1
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Basalla JL, Ghalmi M, Hoang Y, Dow RE, Vecchiarelli AG. An invariant C-terminal tryptophan in McdB mediates its interaction and positioning function with carboxysomes. Mol Biol Cell 2024; 35:ar107. [PMID: 38922842 DOI: 10.1091/mbc.e23-11-0443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024] Open
Abstract
Bacterial microcompartments (BMCs) are widespread, protein-based organelles that regulate metabolism. The model for studying BMCs is the carboxysome, which facilitates carbon fixation in several autotrophic bacteria. Carboxysomes can be distinguished as type α or β, which are structurally and phyletically distinct. We recently characterized the maintenance of carboxysome distribution (Mcd) systems responsible for spatially regulating α- and β-carboxysomes, consisting of the proteins McdA and McdB. McdA is an ATPase that drives carboxysome positioning, and McdB is the adaptor protein that directly interacts with carboxysomes to provide cargo specificity. The molecular features of McdB proteins that specify their interactions with carboxysomes, and whether these are similar between α- and β-carboxysomes, remain unknown. Here, we identify C-terminal motifs containing an invariant tryptophan necessary for α- and β-McdBs to associate with α- and β-carboxysomes, respectively. Substituting this tryptophan with other aromatic residues reveals corresponding gradients in the efficiency of carboxysome colocalization and positioning by McdB in vivo. Intriguingly, these gradients also correlate with the ability of McdB to form condensates in vitro. The results reveal a shared mechanism underlying McdB adaptor protein binding to carboxysomes, and potentially other BMCs. Our findings also implicate condensate formation as playing a key role in this association.
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Affiliation(s)
- Joseph L Basalla
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Maria Ghalmi
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Y Hoang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Rachel E Dow
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Anthony G Vecchiarelli
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
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2
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Rijal A, Johnson ET, Curtis PD. Upstream CtrA-binding sites both induce and repress pilin gene expression in Caulobacter crescentus. BMC Genomics 2024; 25:703. [PMID: 39030481 PMCID: PMC11264516 DOI: 10.1186/s12864-024-10533-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 06/17/2024] [Indexed: 07/21/2024] Open
Abstract
Pili are bacterial surface structures important for surface adhesion. In the alphaproteobacterium Caulobacter crescentus, the global regulator CtrA activates transcription of roughly 100 genes, including pilA which codes for the pilin monomer that makes up the pilus filament. While most CtrA-activated promoters have a single CtrA-binding site at the - 35 position and are induced at the early to mid-predivisional cell stage, the pilA promoter has 3 additional upstream CtrA-binding sites and it is induced at the late predivisional cell stage. Reporter constructs where these additional sites were disrupted by deletion or mutation led to increased activity compared to the WT promoter. In synchronized cultures, these mutations caused pilA transcription to occur approximately 20 min earlier than WT. The results suggested that the site overlapping the - 35 position drives pilA gene expression while the other upstream CtrA-binding sites serve to reduce and delay expression. EMSA experiments showed that the - 35 Site has lower affinity for CtrA∼P compared to the other sites, suggesting binding site affinity may be involved in the delay mechanism. Mutating the upstream inhibitory CtrA-binding sites in the pilA promoter caused significantly higher numbers of pre-divisional cells to express pili, and phage survival assays showed this strain to be significantly more sensitive to pilitropic phage. These results suggest that pilA regulation evolved in C. crescentus to provide an ecological advantage within the context of phage infection.
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Affiliation(s)
- Anurag Rijal
- Department of Biology, University of Mississippi, University, 402 Shoemaker Hall, Oxford, MS, 38677, USA
| | - Eli T Johnson
- Department of Biology, University of Mississippi, University, 402 Shoemaker Hall, Oxford, MS, 38677, USA
| | - Patrick D Curtis
- Department of Biology, University of Mississippi, University, 402 Shoemaker Hall, Oxford, MS, 38677, USA.
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3
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Taguchi A, Nakashima R, Nishino K. Structural Basis of Nucleotide Selectivity in Pyruvate Kinase. J Mol Biol 2024; 436:168708. [PMID: 39009072 DOI: 10.1016/j.jmb.2024.168708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 07/09/2024] [Accepted: 07/10/2024] [Indexed: 07/17/2024]
Abstract
Nucleoside triphosphates are indispensable in numerous biological processes, with enzymes involved in their biogenesis playing pivotal roles in cell proliferation. Pyruvate kinase (PYK), commonly regarded as the terminal glycolytic enzyme that generates ATP in tandem with pyruvate, is also capable of synthesizing a wide range of nucleoside triphosphates from their diphosphate precursors. Despite their substrate promiscuity, some PYKs show preference towards specific nucleotides, suggesting an underlying mechanism for differentiating nucleotide bases. However, the thorough characterization of this mechanism has been hindered by the paucity of nucleotide-bound PYK structures. Here, we present crystal structures of Streptococcus pneumoniae PYK in complex with four different nucleotides. These structures facilitate direct comparison of the protein-nucleotide interactions and offer structural insights into its pronounced selectivity for GTP synthesis. Notably, this selectivity is dependent on a sequence motif in the nucleotide recognition site that is widely present among prokaryotic PYKs, particularly in Firmicutes species. We show that pneumococcal cell growth is significantly impaired when expressing a PYK variant with compromised GTP and UTP synthesis activity, underscoring the importance of PYK in maintaining nucleotide homeostasis. Our findings collectively advance our understanding of PYK biochemistry and prokaryotic metabolism.
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Affiliation(s)
- Atsushi Taguchi
- SANKEN, Osaka University, Ibaraki, Osaka 567-0047, Japan; Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan.
| | | | - Kunihiko Nishino
- SANKEN, Osaka University, Ibaraki, Osaka 567-0047, Japan; Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan; Center for Infectious Disease Education and Research, Osaka University, Suita, Osaka 565-0871, Japan.
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4
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Halte M, Andrianova EP, Goosmann C, Chevance FFV, Hughes KT, Zhulin IB, Erhardt M. FlhE functions as a chaperone to prevent formation of periplasmic flagella in Gram-negative bacteria. Nat Commun 2024; 15:5921. [PMID: 39004688 PMCID: PMC11247099 DOI: 10.1038/s41467-024-50278-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 07/04/2024] [Indexed: 07/16/2024] Open
Abstract
The bacterial flagellum, which facilitates motility, is composed of ~20 structural proteins organized into a long extracellular filament connected to a cytoplasmic rotor-stator complex via a periplasmic rod. Flagellum assembly is regulated by multiple checkpoints that ensure an ordered gene expression pattern coupled to the assembly of the various building blocks. Here, we use epifluorescence, super-resolution, and transmission electron microscopy to show that the absence of a periplasmic protein (FlhE) prevents proper flagellar morphogenesis and results in the formation of periplasmic flagella in Salmonella enterica. The periplasmic flagella disrupt cell wall synthesis, leading to a loss of normal cell morphology resulting in cell lysis. We propose that FlhE functions as a periplasmic chaperone to control assembly of the periplasmic rod, thus preventing formation of periplasmic flagella.
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Affiliation(s)
- Manuel Halte
- Institute of Biology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115, Berlin, Germany.
| | | | - Christian Goosmann
- Max Planck Institute for Infection Biology, Charitéplatz 1, 10117, Berlin, Germany
| | | | - Kelly T Hughes
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
| | - Igor B Zhulin
- Department of Microbiology, The Ohio State University, Columbus, OH, 43210, USA
| | - Marc Erhardt
- Institute of Biology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115, Berlin, Germany.
- Max Planck Unit for the Science of Pathogens, Charitéplatz 1, 10117, Berlin, Germany.
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5
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Li B, Srivastava S, Shaikh M, Mereddy G, Garcia MR, Shah A, Ofori-Anyinam N, Chu T, Cheney N, Yang JH. Bioenergetic stress potentiates antimicrobial resistance and persistence. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.12.603336. [PMID: 39026737 PMCID: PMC11257553 DOI: 10.1101/2024.07.12.603336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Antimicrobial resistance (AMR) is a global health crisis and there is an urgent need to better understand AMR mechanisms. Antibiotic treatment alters several aspects of bacterial physiology, including increased ATP utilization, carbon metabolism, and reactive oxygen species (ROS) formation. However, how the "bioenergetic stress" induced by increased ATP utilization affects treatment outcomes is unknown. Here we utilized a synthetic biology approach to study the direct effects of bioenergetic stress on antibiotic efficacy. We engineered a genetic system that constitutively hydrolyzes ATP or NADH in Escherichia coli. We found that bioenergetic stress potentiates AMR evolution via enhanced ROS production, mutagenic break repair, and transcription-coupled repair. We also find that bioenergetic stress potentiates antimicrobial persistence via potentiated stringent response activation. We propose a unifying model that antibiotic-induced antimicrobial resistance and persistence is caused by antibiotic-induced. This has important implications for preventing or curbing the spread of AMR infections.
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6
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Vadakkepat AK, Xue S, Redzej A, Smith TK, Ho BT, Waksman G. Cryo-EM structure of the R388 plasmid conjugative pilus reveals a helical polymer characterized by an unusual pilin/phospholipid binary complex. Structure 2024:S0969-2126(24)00227-2. [PMID: 39002540 DOI: 10.1016/j.str.2024.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/14/2024] [Accepted: 06/18/2024] [Indexed: 07/15/2024]
Abstract
Bacterial conjugation is a process by which DNA is transferred unidirectionally from a donor cell to a recipient cell. It is the main means by which antibiotic resistance genes spread among bacterial populations. It is crucially dependent upon the elaboration of an extracellular appendage, termed "pilus," by a large double-membrane-spanning secretion system termed conjugative "type IV secretion system." Here we present the structure of the conjugative pilus encoded by the R388 plasmid. We demonstrate that, as opposed to all conjugative pili produced so far for cryoelectron microscopy (cryo-EM) structure determination, the conjugative pilus encoded by the R388 plasmid is greatly stimulated by the presence of recipient cells. Comparison of its cryo-EM structure with existing conjugative pilus structures highlights a number of important differences between the R388 pilus structure and that of its homologs, the most prominent being the highly distinctive conformation of its bound lipid.
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Affiliation(s)
- Abhinav K Vadakkepat
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, Malet Street, London WC1E 7HX, UK.
| | - Songlin Xue
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
| | - Adam Redzej
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, Malet Street, London WC1E 7HX, UK
| | - Terry K Smith
- BSRC, School of Biology, University of St Andrews, St Andrews KY16 9AJ, UK
| | - Brian T Ho
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, Malet Street, London WC1E 7HX, UK; Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
| | - Gabriel Waksman
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, Malet Street, London WC1E 7HX, UK; Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK.
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7
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Winther AR, Salehian Z, Bøe CA, Nesdal M, Håvarstein LS, Kjos M, Straume D. Decreased susceptibility to viscosin in Streptococcus pneumoniae. Microbiol Spectr 2024:e0062424. [PMID: 38958463 DOI: 10.1128/spectrum.00624-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 05/30/2024] [Indexed: 07/04/2024] Open
Abstract
Growing numbers of infections caused by antibiotic-resistant Streptococcus pneumoniae strains are a major concern for healthcare systems that will require new antibiotics for treatment as well as preventative measures that reduce the number of infections. Lipopeptides are antimicrobial molecules, of which some are used as antibiotics, including the last resort antibiotics daptomycin and polymyxins. Here we have studied the antimicrobial effect of the cyclic lipopeptide viscosin on S. pneumoniae growth and morphology. Most lipopeptides function as surfactants that create pores in membrane layers, which is regarded as their main antimicrobial activity. We show that viscosin can inhibit growth of S. pneumoniae without disintegration of the cytoplasmic membrane. Instead, the cells developed abnormal shapes and misplaced new division sites. The cell wall of these bacteria appeared less dense in electron microscopy images, suggesting that viscosin interfered with normal cell wall synthesis. Corroborating this observation, a luciferase reporter assay was used to show that the two-component systems LiaFSR and CiaRH, which are known to be activated upon cell wall stress, were strongly induced by viscosin. Furthermore, a mutant displaying 1.8-fold decreased susceptibility to viscosin was generated by sequential exposure to increasing concentrations of the lipopeptide. The mutant suffered from significant fitness loss and had mutations in genes involved in fatty acid synthesis, teichoic acid synthesis, and cell wall synthesis as well as transcription and translation. How these mutations might be linked to decreased viscosin susceptibility is discussed.IMPORTANCEStreptococcus pneumoniae is a leading cause of bacterial pneumonia, sepsis, and meningitis in children, and the incidence of infections caused by antibiotic-resistant strains is increasing. Development of new antibiotics is therefore necessary to treat these types of infections in the future. Here, we have studied the activity of the antimicrobial lipopeptide viscosin on S. pneumoniae and show that in addition to having the typical membrane destabilizing activity of lipopeptides, viscosin inhibits pneumococcal growth by obstructing normal cell wall synthesis. This suggests a more specific mode of action than just the surfactant activity. Furthermore, we show that S. pneumoniae does not easily acquire resistance to viscosin, which makes it a promising molecule to explore further, for example, by synthesizing less toxic derivates that can be tested for therapeutic potential.
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Affiliation(s)
- Anja Ruud Winther
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Zhian Salehian
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | | | - Malene Nesdal
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Leiv Sigve Håvarstein
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Morten Kjos
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Daniel Straume
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
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8
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Toussaint F, Henry de Frahan M, Poncelet F, Ladrière JM, Horvath P, Fremaux C, Hols P. Unveiling the regulatory network controlling natural transformation in lactococci. PLoS Genet 2024; 20:e1011340. [PMID: 38950059 PMCID: PMC11244767 DOI: 10.1371/journal.pgen.1011340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 07/12/2024] [Accepted: 06/13/2024] [Indexed: 07/03/2024] Open
Abstract
Lactococcus lactis is a lactic acid bacterium of major importance for food fermentation and biotechnological applications. The ability to manipulate its genome quickly and easily through competence for DNA transformation would accelerate its general use as a platform for a variety of applications. Natural transformation in this species requires the activation of the master regulator ComX. However, the growth conditions that lead to spontaneous transformation, as well as the regulators that control ComX production, are unknown. Here, we identified the carbon source, nitrogen supply, and pH as key factors controlling competence development in this species. Notably, we showed that these conditions are sensed by three global regulators (i.e., CcpA, CodY, and CovR), which repress comX transcription directly. Furthermore, our systematic inactivation of known signaling systems suggests that classical pheromone-sensing regulators are not involved. Finally, we revealed that the ComX-degrading MecA-ClpCP machinery plays a predominant role based on the identification of a single amino-acid substitution in the adaptor protein MecA of a highly transformable strain. Contrasting with closely-related streptococci, the master competence regulator in L. lactis is regulated both proximally by general sensors and distantly by the Clp degradation machinery. This study not only highlights the diversity of regulatory networks for competence control in Gram-positive bacteria, but it also paves the way for the use of natural transformation as a tool to manipulate this biotechnologically important bacterium.
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Affiliation(s)
- Frédéric Toussaint
- Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Marie Henry de Frahan
- Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Félix Poncelet
- Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Jean-Marc Ladrière
- IFF Health & Biosciences, Danisco France SAS, Dangé-Saint-Romain, France
| | - Philippe Horvath
- IFF Health & Biosciences, Danisco France SAS, Dangé-Saint-Romain, France
| | - Christophe Fremaux
- IFF Health & Biosciences, Danisco France SAS, Dangé-Saint-Romain, France
| | - Pascal Hols
- Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
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9
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Barrows JM, Talavera-Figueroa BK, Payne IP, Smith EL, Goley ED. GTPase activity regulates FtsZ ring positioning in Caulobacter crescentus. Mol Biol Cell 2024; 35:ar97. [PMID: 38758654 PMCID: PMC11244171 DOI: 10.1091/mbc.e23-09-0365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 05/06/2024] [Accepted: 05/08/2024] [Indexed: 05/19/2024] Open
Abstract
Bacterial cell division is crucial for replication and requires careful coordination via proteins collectively called the divisome. The tubulin-like GTPase FtsZ is the master regulator of this process and serves to recruit downstream divisome proteins and regulate their activities. Upon assembling at mid-cell, FtsZ exhibits treadmilling motion driven by GTP binding and hydrolysis. Treadmilling is proposed to play roles in Z-ring condensation and in distribution and regulation of peptidoglycan (PG) cell wall enzymes. FtsZ polymer superstructure and dynamics are central to its function, yet their regulation is incompletely understood. We addressed these gaps in knowledge by evaluating the contribution of GTPase activity to FtsZ's function in vitro and in Caulobacter crescentus cells. We observed that a lethal mutation that abrogates FtsZ GTP hydrolysis impacts FtsZ dynamics and Z-ring positioning, but not constriction. Aberrant Z-ring positioning was due to insensitivity to the FtsZ regulator MipZ when GTPase activity is reduced. Z-ring mislocalization resulted in DNA damage, likely due to constriction over the nucleoid. Collectively, our results indicate that GTP hydrolysis serves primarily to position the Z-ring at mid-cell in Caulobacter. Proper Z-ring localization is required for effective coordination with chromosome segregation to prevent DNA damage and ensure successful cell division.
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Affiliation(s)
- Jordan M. Barrows
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | | | - Isaac P. Payne
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Erika L. Smith
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Erin D. Goley
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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10
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Diaz-Diaz S, Garcia-Montaner A, Vanni R, Murillo-Torres M, Recacha E, Pulido MR, Romero-Muñoz M, Docobo-Pérez F, Pascual A, Rodriguez-Martinez JM. Heterogeneity of SOS response expression in clinical isolates of Escherichia coli influences adaptation to antimicrobial stress. Drug Resist Updat 2024; 75:101087. [PMID: 38678745 DOI: 10.1016/j.drup.2024.101087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 03/22/2024] [Accepted: 04/18/2024] [Indexed: 05/01/2024]
Abstract
In recent years, new evidence has shown that the SOS response plays an important role in the response to antimicrobials, with involvement in the generation of clinical resistance. Here we evaluate the impact of heterogeneous expression of the SOS response in clinical isolates of Escherichia coli on response to the fluoroquinolone, ciprofloxacin. In silico analysis of whole genome sequencing data showed remarkable sequence conservation of the SOS response regulators, RecA and LexA. Despite the genetic homogeneity, our results revealed a marked differential heterogeneity in SOS response activation, both at population and single-cell level, among clinical isolates of E. coli in the presence of subinhibitory concentrations of ciprofloxacin. Four main stages of SOS response activation were identified and correlated with cell filamentation. Interestingly, there was a correlation between clinical isolates with higher expression of the SOS response and further progression to resistance. This heterogeneity in response to DNA damage repair (mediated by the SOS response) and induced by antimicrobial agents could be a new factor with implications for bacterial evolution and survival contributing to the generation of antimicrobial resistance.
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Affiliation(s)
- Sara Diaz-Diaz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen Macarena/CSIC/Universidad de Sevilla, Sevilla, Spain, Sevilla, Spain.
| | - Andrea Garcia-Montaner
- Departamento de Microbiología, Facultad de Medicina, Universidad de Sevilla, Sevilla, Spain
| | - Roberta Vanni
- Departamento de Microbiología, Facultad de Medicina, Universidad de Sevilla, Sevilla, Spain
| | - Marina Murillo-Torres
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen Macarena/CSIC/Universidad de Sevilla, Sevilla, Spain, Sevilla, Spain; Departamento de Microbiología, Facultad de Medicina, Universidad de Sevilla, Sevilla, Spain
| | - Esther Recacha
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen Macarena/CSIC/Universidad de Sevilla, Sevilla, Spain, Sevilla, Spain; Unidad Clínica de Enfermedades Infecciosas y Microbiología, Hospital Universitario Virgen Macarena, Sevilla, Spain; Centro de Investigación Biomédica en Red en Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Marina R Pulido
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen Macarena/CSIC/Universidad de Sevilla, Sevilla, Spain, Sevilla, Spain; Departamento de Microbiología, Facultad de Medicina, Universidad de Sevilla, Sevilla, Spain; Centro de Investigación Biomédica en Red en Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Maria Romero-Muñoz
- Departamento de Microbiología, Facultad de Medicina, Universidad de Sevilla, Sevilla, Spain
| | - Fernando Docobo-Pérez
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen Macarena/CSIC/Universidad de Sevilla, Sevilla, Spain, Sevilla, Spain; Departamento de Microbiología, Facultad de Medicina, Universidad de Sevilla, Sevilla, Spain; Centro de Investigación Biomédica en Red en Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Alvaro Pascual
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen Macarena/CSIC/Universidad de Sevilla, Sevilla, Spain, Sevilla, Spain; Departamento de Microbiología, Facultad de Medicina, Universidad de Sevilla, Sevilla, Spain; Unidad Clínica de Enfermedades Infecciosas y Microbiología, Hospital Universitario Virgen Macarena, Sevilla, Spain; Centro de Investigación Biomédica en Red en Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Jose Manuel Rodriguez-Martinez
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen Macarena/CSIC/Universidad de Sevilla, Sevilla, Spain, Sevilla, Spain; Departamento de Microbiología, Facultad de Medicina, Universidad de Sevilla, Sevilla, Spain; Centro de Investigación Biomédica en Red en Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
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11
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Halte M, Popp PF, Hathcock D, Severn J, Fischer S, Goosmann C, Ducret A, Charpentier E, Tu Y, Lauga E, Erhardt M, Renault TT. Bacterial motility depends on a critical flagellum length and energy-optimised assembly. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.28.599820. [PMID: 38979141 PMCID: PMC11230379 DOI: 10.1101/2024.06.28.599820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
The flagellum is the most complex macromolecular structure known in bacteria and comprised of around two dozen distinct proteins. The main building block of the long, external flagellar filament, flagellin, is secreted through the flagellar type-III secretion system at a remarkable rate of several tens of thousands amino acids per second, significantly surpassing the rates achieved by other pore-based protein secretion systems. The evolutionary implications and potential benefits of this high secretion rate for flagellum assembly and function, however, have remained elusive. In this study, we provide both experimental and theoretical evidence that the flagellar secretion rate has been evolutionarily optimized to facilitate rapid and efficient construction of a functional flagellum. By synchronizing flagellar assembly, we found that a minimal filament length of 2.5 µm was required for swimming motility. Biophysical modelling revealed that this minimal filament length threshold resulted from an elasto-hydrodynamic instability of the whole swimming cell, dependent on the filament length. Furthermore, we developed a stepwise filament labeling method combined with electron microscopy visualization to validate predicted flagellin secretion rates of up to 10,000 amino acids per second. A biophysical model of flagellum growth demonstrates that the observed high flagellin secretion rate efficiently balances filament elongation and energy consumption, thereby enabling motility in the shortest amount of time. Taken together, these insights underscore the evolutionary pressures that have shaped the development and optimization of the flagellum and type-III secretion system, illuminating the intricate interplay between functionality and efficiency in assembly of large macromolecular structures. Significance statement Our study demonstrates how protein secretion of the bacterial flagellum is finely tuned to optimize filament assembly rate and flagellum function while minimizing energy consumption. By measuring flagellar filament lengths and bacterial swimming after initiation of flag-ellum assembly, we were able to establish the minimal filament length necessary for swimming motility, which we rationalized physically as resulting from an elasto-hydrodynamic instability of the swimming cell. Our bio-physical model of flagellum growth further illustrates how the physiological flagellin secretion rate is optimized to maximize filament elongation while conserving energy. These findings illuminate the evolutionary pressures that have shaped the function of the bacterial flagellum and type-III secretion system, driving improvements in bacterial motility and overall fitness.
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12
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Mårli MT, Oppegaard O, Porcellato D, Straume D, Kjos M. Genetic modification of Streptococcus dysgalactiae by natural transformation. mSphere 2024:e0021424. [PMID: 38904369 DOI: 10.1128/msphere.00214-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Accepted: 05/13/2024] [Indexed: 06/22/2024] Open
Abstract
Streptococcus dysgalactiae is an emerging human and animal pathogen. Functional studies of genes involved in virulence of S. dysgalactiae and other pyogenic group streptococci are often hampered by limited genetic tractability. It is known that pyogenic streptococci carry genes required for competence for natural transformation; however, in contrast to other streptococcal subgroups, there is limited evidence for gene transfer by natural transformation in these bacteria. In this study, we systematically assessed the genomes of 179 S. dysgalactiae strains of both human and animal origins (subsp. equisimilis and dysgalactiae, respectively) for the presence of genes required for natural transformation. While a considerable fraction of the strains contained inactive genes, the majority (64.2%) of the strains had an intact gene set. In selected strains, we examined the dynamics of competence activation after addition of competence-inducing pheromones using transcriptional reporter assays and exploratory RNA-seq. Based on these findings, we were able to establish a protocol allowing us to utilize natural transformation to construct deletion mutants by allelic exchange in several S. dysgalactiae strains of both subspecies. As part of the work, we deleted putative lactose utilization genes to study their role in growth on lactose. The data presented here provide new knowledge on the potential of horizonal gene transfer by natural transformation in S. dysgalactiae and, importantly, demonstrates the possibility to exploit natural transformation for genetic engineering in these bacteria. IMPORTANCE Numerous Streptococcus spp. exchange genes horizontally through natural transformation, which also facilitates efficient genetic engineering in these organisms. However, for the pyogenic group of streptococci, including the emerging pathogen Streptococcus dysgalactiae, there is limited experimental evidence for natural transformation. In this study, we demonstrate that natural transformation in vitro indeed is possible in S. dysgalactiae strains under optimal conditions. We utilized this method to perform gene deletion through allelic exchange in several strains, thereby paving the way for more efficient gene engineering methods in pyogenic streptococci.
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Affiliation(s)
- Marita Torrissen Mårli
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Oddvar Oppegaard
- Haukeland University Hospital, University of Bergen, Bergen, Norway
| | - Davide Porcellato
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Daniel Straume
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Morten Kjos
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
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13
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Iyer A, Frallicciardi J, le Paige UBA, Narasimhan S, Luo Y, Sieiro PA, Syga L, van den Brekel F, Tran BM, Tjioe R, Schuurman-Wolters G, Stuart MCA, Baldus M, van Ingen H, Poolman B. The Structure and Function of the Bacterial Osmotically Inducible Protein Y. J Mol Biol 2024; 436:168668. [PMID: 38908784 DOI: 10.1016/j.jmb.2024.168668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 06/14/2024] [Accepted: 06/14/2024] [Indexed: 06/24/2024]
Abstract
The ability to adapt to osmotically diverse and fluctuating environments is critical to the survival and resilience of bacteria that colonize the human gut and urinary tract. Environmental stress often provides cross-protection against other challenges and increases antibiotic tolerance of bacteria. Thus, it is critical to understand how E. coli and other microbes survive and adapt to stress conditions. The osmotically inducible protein Y (OsmY) is significantly upregulated in response to hypertonicity. Yet its function remains unknown for decades. We determined the solution structure and dynamics of OsmY by nuclear magnetic resonance spectroscopy, which revealed that the two Bacterial OsmY and Nodulation (BON) domains of the protein are flexibly linked under low- and high-salinity conditions. In-cell solid-state NMR further indicates that there are no gross structural changes in OsmY as a function of osmotic stress. Using cryo-electron and super-resolution fluorescence microscopy, we show that OsmY attenuates plasmolysis-induced structural changes in E. coli and improves the time to growth resumption after osmotic upshift. Structure-guided mutational and functional studies demonstrate that exposed hydrophobic residues in the BON1 domain are critical for the function of OsmY. We find no evidence for membrane interaction of the BON domains of OsmY, contrary to current assumptions. Instead, at high ionic strength, we observe an interaction with the water channel, AqpZ. Thus, OsmY does not play a simple structural role in E. coli but may influence a cascade of osmoregulatory functions of the cell.
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Affiliation(s)
- Aditya Iyer
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands.
| | - Jacopo Frallicciardi
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Ulric B A le Paige
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Siddarth Narasimhan
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Yanzhang Luo
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Patricia Alvarez Sieiro
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Lukasz Syga
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Floris van den Brekel
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Buu Minh Tran
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Rendy Tjioe
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Gea Schuurman-Wolters
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Marc C A Stuart
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Marc Baldus
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Hugo van Ingen
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands.
| | - Bert Poolman
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands.
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14
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Bakker AT, Kotsogianni I, Avalos M, Punt JM, Liu B, Piermarini D, Gagestein B, Slingerland CJ, Zhang L, Willemse JJ, Ghimire LB, van den Berg RJHBN, Janssen APA, Ottenhoff THM, van Boeckel CAA, van Wezel GP, Ghilarov D, Martin NI, van der Stelt M. Discovery of isoquinoline sulfonamides as allosteric gyrase inhibitors with activity against fluoroquinolone-resistant bacteria. Nat Chem 2024:10.1038/s41557-024-01516-x. [PMID: 38898213 DOI: 10.1038/s41557-024-01516-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 03/22/2024] [Indexed: 06/21/2024]
Abstract
Bacteria have evolved resistance to nearly all known antibacterials, emphasizing the need to identify antibiotics that operate via novel mechanisms. Here we report a class of allosteric inhibitors of DNA gyrase with antibacterial activity against fluoroquinolone-resistant clinical isolates of Escherichia coli. Screening of a small-molecule library revealed an initial isoquinoline sulfonamide hit, which was optimized via medicinal chemistry efforts to afford the more potent antibacterial LEI-800. Target identification studies, including whole-genome sequencing of in vitro selected mutants with resistance to isoquinoline sulfonamides, unanimously pointed to the DNA gyrase complex, an essential bacterial topoisomerase and an established antibacterial target. Using single-particle cryogenic electron microscopy, we determined the structure of the gyrase-LEI-800-DNA complex. The compound occupies an allosteric, hydrophobic pocket in the GyrA subunit and has a mode of action that is distinct from the clinically used fluoroquinolones or any other gyrase inhibitor reported to date. LEI-800 provides a chemotype suitable for development to counter the increasingly widespread bacterial resistance to fluoroquinolones.
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Affiliation(s)
- Alexander T Bakker
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Ioli Kotsogianni
- Biological Chemistry Group, Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Mariana Avalos
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Jeroen M Punt
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Bing Liu
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Diana Piermarini
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Berend Gagestein
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Cornelis J Slingerland
- Biological Chemistry Group, Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Le Zhang
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Joost J Willemse
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Leela B Ghimire
- Department of Molecular Microbiology, John Innes Centre, Norwich, UK
| | | | - Antonius P A Janssen
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Tom H M Ottenhoff
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, the Netherlands
| | - Constant A A van Boeckel
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands
| | - Gilles P van Wezel
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, the Netherlands
| | - Dmitry Ghilarov
- Department of Molecular Microbiology, John Innes Centre, Norwich, UK.
| | - Nathaniel I Martin
- Biological Chemistry Group, Institute of Biology, Leiden University, Leiden, the Netherlands.
| | - Mario van der Stelt
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands.
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15
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Barbuti MD, Lambert E, Myrbråten IS, Ducret A, Stamsås GA, Wilhelm L, Liu X, Salehian Z, Veening JW, Straume D, Grangeasse C, Perez C, Kjos M. The function of CozE proteins is linked to lipoteichoic acid biosynthesis in Staphylococcus aureus. mBio 2024; 15:e0115724. [PMID: 38757970 PMCID: PMC11237490 DOI: 10.1128/mbio.01157-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Accepted: 04/21/2024] [Indexed: 05/18/2024] Open
Abstract
Coordinated membrane and cell wall synthesis is vital for maintaining cell integrity and facilitating cell division in bacteria. However, the molecular mechanisms that underpin such coordination are poorly understood. Here we uncover the pivotal roles of the staphylococcal proteins CozEa and CozEb, members of a conserved family of membrane proteins previously implicated in bacterial cell division, in the biosynthesis of lipoteichoic acids (LTA) and maintenance of membrane homeostasis in Staphylococcus aureus. We establish that there is a synthetic lethal relationship between CozE and UgtP, the enzyme synthesizing the LTA glycolipid anchor Glc2DAG. By contrast, in cells lacking LtaA, the flippase of Glc2DAG, the essentiality of CozE proteins was alleviated, suggesting that the function of CozE proteins is linked to the synthesis and flipping of the glycolipid anchor. CozE proteins were indeed found to modulate the flipping activity of LtaA in vitro. Furthermore, CozEb was shown to control LTA polymer length and stability. Together, these findings establish CozE proteins as novel players in membrane homeostasis and LTA biosynthesis in S. aureus.IMPORTANCELipoteichoic acids are major constituents of the cell wall of Gram-positive bacteria. These anionic polymers are important virulence factors and modulators of antibiotic susceptibility in the important pathogen Staphylococcus aureus. They are also critical for maintaining cell integrity and facilitating proper cell division. In this work, we discover that a family of membrane proteins named CozE is involved in the biosynthesis of lipoteichoic acids (LTAs) in S. aureus. CozE proteins have previously been shown to affect bacterial cell division, but we here show that these proteins affect LTA length and stability, as well as the flipping of glycolipids between membrane leaflets. This new mechanism of LTA control may thus have implications for the virulence and antibiotic susceptibility of S. aureus.
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Affiliation(s)
- Maria Disen Barbuti
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | | | - Ine Storaker Myrbråten
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Adrien Ducret
- Molecular Microbiology and Structural Biochemistry, CNRS UM 5086, Université de Lyon, Lyon, France
| | - Gro Anita Stamsås
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Linus Wilhelm
- Molecular Microbiology and Structural Biochemistry, CNRS UM 5086, Université de Lyon, Lyon, France
| | - Xue Liu
- Department of Pathogen, Biology, International Cancer Center, Shenzhen University Medical School, Shenzhen, Guangdong, China
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Zhian Salehian
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Daniel Straume
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Christophe Grangeasse
- Molecular Microbiology and Structural Biochemistry, CNRS UM 5086, Université de Lyon, Lyon, France
| | - Camilo Perez
- Biozentrum, University of Basel, Basel, Switzerland
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Morten Kjos
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
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16
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Abrahamsen HL, Sanford TC, Collamore CE, Johnstone BA, Coyne MJ, García-Bayona L, Christie MP, Evans JC, Farrand AJ, Flores K, Morton CJ, Parker MW, Comstock LE, Tweten RK. Distant relatives of a eukaryotic cell-specific toxin family evolved a complement-like mechanism to kill bacteria. Nat Commun 2024; 15:5028. [PMID: 38866748 PMCID: PMC11169675 DOI: 10.1038/s41467-024-49103-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 05/22/2024] [Indexed: 06/14/2024] Open
Abstract
Cholesterol-dependent cytolysins (CDCs) comprise a large family of pore-forming toxins produced by Gram-positive bacteria, which are used to attack eukaryotic cells. Here, we functionally characterize a family of 2-component CDC-like (CDCL) toxins produced by the Gram-negative Bacteroidota that form pores by a mechanism only described for the mammalian complement membrane attack complex (MAC). We further show that the Bacteroides CDCLs are not eukaryotic cell toxins like the CDCs, but instead bind to and are proteolytically activated on the surface of closely related species, resulting in pore formation and cell death. The CDCL-producing Bacteroides is protected from the effects of its own CDCL by the presence of a surface lipoprotein that blocks CDCL pore formation. These studies suggest a prevalent mode of bacterial antagonism by a family of two-component CDCLs that function like mammalian MAC and that are wide-spread in the gut microbiota of diverse human populations.
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Affiliation(s)
- Hunter L Abrahamsen
- Department of Microbiology & Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Tristan C Sanford
- Department of Microbiology & Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Casie E Collamore
- Department of Microbiology & Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Bronte A Johnstone
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Michael J Coyne
- Duchossois Family Institute and Department of Microbiology, University of Chicago, Chicago, IL, USA
| | - Leonor García-Bayona
- Duchossois Family Institute and Department of Microbiology, University of Chicago, Chicago, IL, USA
| | - Michelle P Christie
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jordan C Evans
- Department of Microbiology & Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Wheeler Bio, Oklahoma City, OK, 73104, USA
| | - Allison J Farrand
- Department of Microbiology & Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Wheeler Bio, Oklahoma City, OK, 73104, USA
| | - Katia Flores
- Duchossois Family Institute and Department of Microbiology, University of Chicago, Chicago, IL, USA
| | - Craig J Morton
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia
- CSIRO Biomedical Manufacturing Program, Clayton, VIC, 3168, Australia
| | - Michael W Parker
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia.
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, 3010, Australia.
- Australian Cancer Research Foundation Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, Fitzroy, VIC, 2065, Australia.
| | - Laurie E Comstock
- Duchossois Family Institute and Department of Microbiology, University of Chicago, Chicago, IL, USA.
| | - Rodney K Tweten
- Department of Microbiology & Immunology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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17
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Xu Q, Tang L, Liu W, Xu N, Hu Y, Zhang Y, Chen S. Phage protein Gp11 blocks Staphylococcus aureus cell division by inhibiting peptidoglycan biosynthesis. mBio 2024; 15:e0067924. [PMID: 38752726 PMCID: PMC11237401 DOI: 10.1128/mbio.00679-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 04/10/2024] [Indexed: 06/13/2024] Open
Abstract
Phages and bacteria have a long history of co-evolution. However, these dynamics of phage-host interactions are still largely unknown; identification of phage inhibitors that remodel host metabolism will provide valuable information for target development for antimicrobials. Here, we perform a comprehensive screen for early-gene products of ΦNM1 that inhibit cell growth in Staphylococcus aureus. A small membrane protein, Gp11, with inhibitory effects on S. aureus cell division was identified. A bacterial two-hybrid library containing 345 essential S. aureus genes was constructed to screen for targets of Gp11, and Gp11 was found to interact with MurG and DivIC. Defects in cell growth and division caused by Gp11 were dependent on MurG and DivIC, which was further confirmed using CRISPRi hypersensitivity assay. Gp11 interacts with MurG, the protein essential for cell wall formation, by inhibiting the production of lipid II to regulate peptidoglycan (PG) biosynthesis on the cell membrane. Gp11 also interacts with cell division protein DivIC, an essential part of the division machinery necessary for septal cell wall assembly, to disrupt the recruitment of division protein FtsW. Mutations in Gp11 result in loss of its ability to cause growth defects, whereas infection with phage in which the gp11 gene has been deleted showed a significant increase in lipid II production in S. aureus. Together, our findings reveal that a phage early-gene product interacts with essential host proteins to disrupt PG biosynthesis and block S. aureus cell division, suggesting a potential pathway for the development of therapeutic approaches to treat pathogenic bacterial infections. IMPORTANCE Understanding the interplay between phages and their hosts is important for the development of novel therapies against pathogenic bacteria. Although phages have been used to control methicillin-resistant Staphylococcus aureus infections, our knowledge related to the processes in the early stages of phage infection is still limited. Owing to the fact that most of the phage early proteins have been classified as hypothetical proteins with uncertain functions, we screened phage early-gene products that inhibit cell growth in S. aureus, and one protein, Gp11, selectively targets essential host genes to block the synthesis of the peptidoglycan component lipid II, ultimately leading to cell growth arrest in S. aureus. Our study provides a novel insight into the strategy by which Gp11 blocks essential host cellular metabolism to influence phage-host interaction. Importantly, dissecting the interactions between phages and host cells will contribute to the development of new and effective therapies to treat bacterial infections.
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Affiliation(s)
- Qi Xu
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Li Tang
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Weilin Liu
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Neng Xu
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Yangbo Hu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Yong Zhang
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
| | - Shiyun Chen
- CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
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18
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Yang L, Lawhorn S, Bongrand C, Kosmopoulos JC, Kuwabara J, VanNieuwenhze M, Mandel MJ, McFall-Ngai M, Ruby E. Bacterial growth dynamics in a rhythmic symbiosis. Mol Biol Cell 2024; 35:ar79. [PMID: 38598294 PMCID: PMC11238090 DOI: 10.1091/mbc.e24-01-0044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/01/2024] [Accepted: 04/04/2024] [Indexed: 04/12/2024] Open
Abstract
The symbiotic relationship between the bioluminescent bacterium Vibrio fischeri and the bobtail squid Euprymna scolopes serves as a valuable system to investigate bacterial growth and peptidoglycan (PG) synthesis within animal tissues. To better understand the growth dynamics of V. fischeri in the crypts of the light-emitting organ of its juvenile host, we showed that, after the daily dawn-triggered expulsion of most of the population, the remaining symbionts rapidly proliferate for ∼6 h. At that point the population enters a period of extremely slow growth that continues throughout the night until the next dawn. Further, we found that PG synthesis by the symbionts decreases as they enter the slow-growing stage. Surprisingly, in contrast to the most mature crypts (i.e., Crypt 1) of juvenile animals, most of the symbiont cells in the least mature crypts (i.e., Crypt 3) were not expelled and, instead, remained in the slow-growing state throughout the day, with almost no cell division. Consistent with this observation, the expression of the gene encoding the PG-remodeling enzyme, L,D-transpeptidase (LdtA), was greatest during the slowly growing stage of Crypt 1 but, in contrast, remained continuously high in Crypt 3. Finally, deletion of the ldtA gene resulted in a symbiont that grew and survived normally in culture, but was increasingly defective in competing against its parent strain in the crypts. This result suggests that remodeling of the PG to generate additional 3-3 linkages contributes to the bacterium's fitness in the symbiosis, possibly in response to stresses encountered during the very slow-growing stage.
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Affiliation(s)
- Liu Yang
- Carnegie Institution for Science, Pasadena, CA 91101
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
| | - Susannah Lawhorn
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
| | - Clotilde Bongrand
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
| | - James C. Kosmopoulos
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI 53706
| | - Jill Kuwabara
- Carnegie Institution for Science, Pasadena, CA 91101
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
| | | | - Mark J. Mandel
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI 53706
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI 53706
| | - Margaret McFall-Ngai
- Carnegie Institution for Science, Pasadena, CA 91101
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Edward Ruby
- Carnegie Institution for Science, Pasadena, CA 91101
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125
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19
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Shroff H, Testa I, Jug F, Manley S. Live-cell imaging powered by computation. Nat Rev Mol Cell Biol 2024; 25:443-463. [PMID: 38378991 DOI: 10.1038/s41580-024-00702-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2024] [Indexed: 02/22/2024]
Abstract
The proliferation of microscopy methods for live-cell imaging offers many new possibilities for users but can also be challenging to navigate. The prevailing challenge in live-cell fluorescence microscopy is capturing intra-cellular dynamics while preserving cell viability. Computational methods can help to address this challenge and are now shifting the boundaries of what is possible to capture in living systems. In this Review, we discuss these computational methods focusing on artificial intelligence-based approaches that can be layered on top of commonly used existing microscopies as well as hybrid methods that integrate computation and microscope hardware. We specifically discuss how computational approaches can improve the signal-to-noise ratio, spatial resolution, temporal resolution and multi-colour capacity of live-cell imaging.
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Affiliation(s)
- Hari Shroff
- Janelia Research Campus, Howard Hughes Medical Institute (HHMI), Ashburn, VA, USA
| | - Ilaria Testa
- Department of Applied Physics and Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Florian Jug
- Fondazione Human Technopole (HT), Milan, Italy
| | - Suliana Manley
- Institute of Physics, School of Basic Sciences, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland.
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20
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Ng WL, Rego EH. A nucleoid-associated protein is involved in the emergence of antibiotic resistance by promoting the frequent exchange of the replicative DNA polymerase in Mycobacterium smegmatis. mSphere 2024; 9:e0012224. [PMID: 38591887 PMCID: PMC11237743 DOI: 10.1128/msphere.00122-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 03/16/2024] [Indexed: 04/10/2024] Open
Abstract
Antibiotic resistance in Mycobacterium tuberculosis exclusively originates from chromosomal mutations, either during normal DNA replication or under stress, when the expression of error-prone DNA polymerases increases to repair damaged DNA. To bypass DNA lesions and catalyze error-prone DNA synthesis, translesion polymerases must be able to access the DNA, temporarily replacing the high-fidelity replicative polymerase. The mechanisms that govern polymerase exchange are not well understood, especially in mycobacteria. Here, using a suite of quantitative fluorescence imaging techniques, we discover that in Mycobacterium smegmatis, as in other bacterial species, the replicative polymerase, DnaE1, exchanges at a timescale much faster than that of DNA replication. Interestingly, this fast exchange rate depends on an actinobacteria-specific nucleoid-associated protein (NAP), Lsr2. In cells missing lsr2, DnaE1 exchanges less frequently, and the chromosome is replicated more faithfully. Additionally, in conditions that damage DNA, cells lacking lsr2 load the complex needed to bypass DNA lesions less effectively and, consistently, replicate with higher fidelity but exhibit growth defects. Together, our results show that Lsr2 promotes dynamic flexibility of the mycobacterial replisome, which is critical for robust cell growth and lesion repair in conditions that damage DNA. IMPORTANCE Unlike many other pathogens, Mycobacterium tuberculosis has limited ability for horizontal gene transfer, a major mechanism for developing antibiotic resistance. Thus, the mechanisms that facilitate chromosomal mutagenesis are of particular importance in mycobacteria. Here, we show that Lsr2, a nucleoid-associated protein, has a novel role in DNA replication and mutagenesis in the model mycobacterium Mycobacterium smegmatis. We find that Lsr2 promotes the fast exchange rate of the replicative DNA polymerase, DnaE1, at the replication fork and is important for the effective loading of the DnaE2-ImuA'-ImuB translesion complex. Without lsr2, M. smegmatis replicates its chromosome more faithfully and acquires resistance to rifampin at a lower rate, but at the cost of impaired survival to DNA damaging agents. Together, our work establishes Lsr2 as a potential factor in the emergence of mycobacterial antibiotic resistance.
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Affiliation(s)
- Wei L Ng
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - E Hesper Rego
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
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21
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Kaczmarczyk A, van Vliet S, Jakob RP, Teixeira RD, Scheidat I, Reinders A, Klotz A, Maier T, Jenal U. A genetically encoded biosensor to monitor dynamic changes of c-di-GMP with high temporal resolution. Nat Commun 2024; 15:3920. [PMID: 38724508 PMCID: PMC11082216 DOI: 10.1038/s41467-024-48295-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 04/26/2024] [Indexed: 05/12/2024] Open
Abstract
Monitoring changes of signaling molecules and metabolites with high temporal resolution is key to understanding dynamic biological systems. Here, we use directed evolution to develop a genetically encoded ratiometric biosensor for c-di-GMP, a ubiquitous bacterial second messenger regulating important biological processes like motility, surface attachment, virulence and persistence. The resulting biosensor, cdGreen2, faithfully tracks c-di-GMP in single cells and with high temporal resolution over extended imaging times, making it possible to resolve regulatory networks driving bimodal developmental programs in different bacterial model organisms. We further adopt cdGreen2 as a simple tool for in vitro studies, facilitating high-throughput screens for compounds interfering with c-di-GMP signaling and biofilm formation. The sensitivity and versatility of cdGreen2 could help reveal c-di-GMP dynamics in a broad range of microorganisms with high temporal resolution. Its design principles could also serve as a blueprint for the development of similar, orthogonal biosensors for other signaling molecules, metabolites and antibiotics.
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Affiliation(s)
- Andreas Kaczmarczyk
- Biozentrum, University of Basel, Spitalstrasse 41, 4056, Basel, Switzerland.
| | - Simon van Vliet
- Biozentrum, University of Basel, Spitalstrasse 41, 4056, Basel, Switzerland
| | - Roman Peter Jakob
- Biozentrum, University of Basel, Spitalstrasse 41, 4056, Basel, Switzerland
| | | | - Inga Scheidat
- Biozentrum, University of Basel, Spitalstrasse 41, 4056, Basel, Switzerland
| | - Alberto Reinders
- Biozentrum, University of Basel, Spitalstrasse 41, 4056, Basel, Switzerland
| | - Alexander Klotz
- Biozentrum, University of Basel, Spitalstrasse 41, 4056, Basel, Switzerland
| | - Timm Maier
- Biozentrum, University of Basel, Spitalstrasse 41, 4056, Basel, Switzerland
| | - Urs Jenal
- Biozentrum, University of Basel, Spitalstrasse 41, 4056, Basel, Switzerland.
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22
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Brüwer JD, Sidhu C, Zhao Y, Eich A, Rößler L, Orellana LH, Fuchs BM. Globally occurring pelagiphage infections create ribosome-deprived cells. Nat Commun 2024; 15:3715. [PMID: 38698041 PMCID: PMC11066056 DOI: 10.1038/s41467-024-48172-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 04/22/2024] [Indexed: 05/05/2024] Open
Abstract
Phages play an essential role in controlling bacterial populations. Those infecting Pelagibacterales (SAR11), the dominant bacteria in surface oceans, have been studied in silico and by cultivation attempts. However, little is known about the quantity of phage-infected cells in the environment. Using fluorescence in situ hybridization techniques, we here show pelagiphage-infected SAR11 cells across multiple global ecosystems and present evidence for tight community control of pelagiphages on the SAR11 hosts in a case study. Up to 19% of SAR11 cells were phage-infected during a phytoplankton bloom, coinciding with a ~90% reduction in SAR11 cell abundance within 5 days. Frequently, a fraction of the infected SAR11 cells were devoid of detectable ribosomes, which appear to be a yet undescribed possible stage during pelagiphage infection. We dubbed such cells zombies and propose, among other possible explanations, a mechanism in which ribosomal RNA is used as a resource for the synthesis of new phage genomes. On a global scale, we detected phage-infected SAR11 and zombie cells in the Atlantic, Pacific, and Southern Oceans. Our findings illuminate the important impact of pelagiphages on SAR11 populations and unveil the presence of ribosome-deprived zombie cells as part of the infection cycle.
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Affiliation(s)
- Jan D Brüwer
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany.
| | - Chandni Sidhu
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany
| | - Yanlin Zhao
- College of Juncao Science and Ecology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Andreas Eich
- PSL Research University: EPHE-UPVD-CNRS,UAR 3278 CRIOBE, Moorea, French Polynesia
| | - Leonard Rößler
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany
| | - Luis H Orellana
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany
| | - Bernhard M Fuchs
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany.
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23
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Adeleye SA, Yadavalli SS. Queuosine biosynthetic enzyme, QueE moonlights as a cell division regulator. PLoS Genet 2024; 20:e1011287. [PMID: 38768229 PMCID: PMC11142719 DOI: 10.1371/journal.pgen.1011287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 05/31/2024] [Accepted: 05/03/2024] [Indexed: 05/22/2024] Open
Abstract
In many organisms, stress responses to adverse environments can trigger secondary functions of certain proteins by altering protein levels, localization, activity, or interaction partners. Escherichia coli cells respond to the presence of specific cationic antimicrobial peptides by strongly activating the PhoQ/PhoP two-component signaling system, which regulates genes important for growth under this stress. As part of this pathway, a biosynthetic enzyme called QueE, which catalyzes a step in the formation of queuosine (Q) tRNA modification is upregulated. When cellular QueE levels are high, it co-localizes with the central cell division protein FtsZ at the septal site, blocking division and resulting in filamentous growth. Here we show that QueE affects cell size in a dose-dependent manner. Using alanine scanning mutagenesis of amino acids in the catalytic active site, we pinpoint residues in QueE that contribute distinctly to each of its functions-Q biosynthesis or regulation of cell division, establishing QueE as a moonlighting protein. We further show that QueE orthologs from enterobacteria like Salmonella typhimurium and Klebsiella pneumoniae also cause filamentation in these organisms, but the more distant counterparts from Pseudomonas aeruginosa and Bacillus subtilis lack this ability. By comparative analysis of E. coli QueE with distant orthologs, we elucidate a unique region in this protein that is responsible for QueE's secondary function as a cell division regulator. A dual-function protein like QueE is an exception to the conventional model of "one gene, one enzyme, one function", which has divergent roles across a range of fundamental cellular processes including RNA modification and translation to cell division and stress response.
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Affiliation(s)
- Samuel A. Adeleye
- Waksman Institute of Microbiology and Department of Genetics, Rutgers University, Piscataway New Jersey, United States of America
| | - Srujana S. Yadavalli
- Waksman Institute of Microbiology and Department of Genetics, Rutgers University, Piscataway New Jersey, United States of America
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24
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Castagnini D, Palma K, Jara-Wilde J, Navarro N, González MJ, Toledo J, Canales-Huerta N, Scavone P, Härtel S. Proteus mirabilis biofilm expansion microscopy yields over 4-fold magnification for super-resolution of biofilm structure and subcellular DNA organization. J Microbiol Methods 2024; 220:106927. [PMID: 38561125 DOI: 10.1016/j.mimet.2024.106927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/04/2024]
Abstract
Bacterial biofilms form when bacteria attach to surfaces and generate an extracellular matrix that embeds and stabilizes a growing community. Detailed visualization and quantitative analysis of biofilm architecture by optical microscopy are limited by the law of diffraction. Expansion Microscopy (ExM) is a novel Super-Resolution technique where specimens are physically enlarged by a factor of ∼4, prior to observation by conventional fluorescence microscopy. ExM requires homogenization of rigid constituents of biological components by enzymatic digestion. We developed an ExM approach capable of expanding 48-h old Proteus mirabilis biofilms 4.3-fold (termed PmbExM), close to the theoretic maximum expansion factor without gross shape distortions. Our protocol, based on lytic and glycoside-hydrolase enzymatic treatments, degrades rigid components in bacteria and extracellular matrix. Our results prove PmbExM to be a versatile and easy-to-use Super-Resolution approach for enabling studies of P. mirabilis biofilm architecture, assembly, and even intracellular features, such as DNA organization.
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Affiliation(s)
- Dante Castagnini
- Laboratory for Scientific Image Analysis SCIAN-Lab, Integrative Biology Program, Institute of Biomedical Sciences ICBM, Faculty of Medicine, University of Chile, Santiago, Chile; Biomedical Neuroscience Institute BNI, Independencia, Santiago, Chile
| | - Karina Palma
- Laboratory for Scientific Image Analysis SCIAN-Lab, Integrative Biology Program, Institute of Biomedical Sciences ICBM, Faculty of Medicine, University of Chile, Santiago, Chile; Biomedical Neuroscience Institute BNI, Independencia, Santiago, Chile; Centro de Informática Médica y Telemedicina CIMT, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Jorge Jara-Wilde
- Laboratory for Scientific Image Analysis SCIAN-Lab, Integrative Biology Program, Institute of Biomedical Sciences ICBM, Faculty of Medicine, University of Chile, Santiago, Chile; Biomedical Neuroscience Institute BNI, Independencia, Santiago, Chile; Centro de Informática Médica y Telemedicina CIMT, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Nicolás Navarro
- Advanced Center for Chronic Diseases ACCDiS, Santiago, Chile.; Laboratorio de Biofilms Microbianos, Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - María José González
- Laboratorio de Biofilms Microbianos, Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Jorge Toledo
- Red de Equipamiento Científico Avanzado REDECA, Institute of Biomedical Sciences ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Nicole Canales-Huerta
- Laboratory for Scientific Image Analysis SCIAN-Lab, Integrative Biology Program, Institute of Biomedical Sciences ICBM, Faculty of Medicine, University of Chile, Santiago, Chile; Biomedical Neuroscience Institute BNI, Independencia, Santiago, Chile
| | - Paola Scavone
- Laboratorio de Biofilms Microbianos, Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Steffen Härtel
- Laboratory for Scientific Image Analysis SCIAN-Lab, Integrative Biology Program, Institute of Biomedical Sciences ICBM, Faculty of Medicine, University of Chile, Santiago, Chile; Biomedical Neuroscience Institute BNI, Independencia, Santiago, Chile; Centro de Informática Médica y Telemedicina CIMT, Faculty of Medicine, University of Chile, Santiago, Chile; National Center for Health Information Systems CENS, Santiago, Chile.; Red de Equipamiento Científico Avanzado REDECA, Institute of Biomedical Sciences ICBM, Faculty of Medicine, University of Chile, Santiago, Chile; Centro de Modelamiento Matemático, Universidad de Chile, Beauchef 851, Casilla 170-3, Santiago, Chile.
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25
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Ithurbide S, de Silva RT, Brown HJ, Shinde V, Duggin IG. A vector system for single and tandem expression of cloned genes and multi-colour fluorescent tagging in Haloferax volcanii. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001461. [PMID: 38787390 PMCID: PMC11165654 DOI: 10.1099/mic.0.001461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 04/26/2024] [Indexed: 05/25/2024]
Abstract
Archaeal cell biology is an emerging field expected to identify fundamental cellular processes, help resolve the deep evolutionary history of cellular life, and contribute new components and functions in biotechnology and synthetic biology. To facilitate these, we have developed plasmid vectors that allow convenient cloning and production of proteins and fusion proteins with flexible, rigid, or semi-rigid linkers in the model archaeon Haloferax volcanii. For protein subcellular localization studies using fluorescent protein (FP) tags, we created vectors incorporating a range of codon-optimized fluorescent proteins for N- or C-terminal tagging, including GFP, mNeonGreen, mCherry, YPet, mTurquoise2 and mScarlet-I. Obtaining functional fusion proteins can be challenging with proteins involved in multiple interactions, mainly due to steric interference. We demonstrated the use of the new vector system to screen for improved function in cytoskeletal protein FP fusions, and identified FtsZ1-FPs that are functional in cell division and CetZ1-FPs that are functional in motility and rod cell development. Both the type of linker and the type of FP influenced the functionality of the resulting fusions. The vector design also facilitates convenient cloning and tandem expression of two genes or fusion genes, controlled by a modified tryptophan-inducible promoter, and we demonstrated its use for dual-colour imaging of tagged proteins in H. volcanii cells. These tools should promote further development and applications of archaeal molecular and cellular biology and biotechnology.
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Affiliation(s)
- Solenne Ithurbide
- The Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Roshali T. de Silva
- The Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Hannah J. Brown
- The Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Vinaya Shinde
- The Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Iain G. Duggin
- The Australian Institute for Microbiology and Infection, University of Technology Sydney, Ultimo, NSW, 2007, Australia
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26
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Arejan NH, Czapski DR, Buonomo JA, Boutte CC. MmpL3, Wag31 and PlrA are involved in coordinating polar growth with peptidoglycan metabolism and nutrient availability. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.29.591792. [PMID: 38746181 PMCID: PMC11092516 DOI: 10.1101/2024.04.29.591792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Cell growth in mycobacteria involves cell wall expansion that is restricted to the cell poles. The DivIVA homolog Wag31 is required for this process, but the molecular mechanism and protein partners of Wag31 have not been described. In this study of Mycobacterium smegmatis, we identify a connection between wag31 and trehalose monomycolate (TMM) transporter mmpl3 in a suppressor screen, and show that Wag31 and polar regulator PlrA are required for MmpL3's polar localization. In addition, the localization of PlrA and MmpL3 are responsive to nutrient and energy deprivation and inhibition of peptidoglycan metabolism. We show that inhibition of MmpL3 causes delocalized cell wall metabolism, but does not delocalize MmpL3 itself. We found that cells with an MmpL3 C-terminal truncation, which is defective for localization, have only minor defects in polar growth, but are impaired in their ability to downregulate cell wall metabolism under stress. Our work suggests that, in addition to its established function in TMM transport, MmpL3 has a second function in regulating global cell wall metabolism in response to stress. Our data are consistent with a model in which the presence of TMMs in the periplasm stimulates polar elongation, and in which the connection between Wag31, PlrA and the C-terminus of MmpL3 is involved in detecting and responding to stress in order to coordinate synthesis of the different layers of the mycobacterial cell wall in changing conditions.
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Affiliation(s)
| | - Desiree R Czapski
- Department of Chemistry and Biochemistry, University of Texas, Arlington
| | - Joseph A Buonomo
- Department of Chemistry and Biochemistry, University of Texas, Arlington
| | - Cara C Boutte
- Department of Biology, University of Texas, Arlington
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27
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Hellenbrand CN, Stevenson DM, Gromek KA, Amador-Noguez D, Hershey DM. A deoxynucleoside triphosphate triphosphohydrolase promotes cell cycle progression in Caulobacter crescentus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.25.591158. [PMID: 38712277 PMCID: PMC11071499 DOI: 10.1101/2024.04.25.591158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Intracellular pools of deoxynucleoside triphosphates (dNTPs) are strictly maintained throughout the cell cycle to ensure accurate and efficient DNA replication. DNA synthesis requires an abundance of dNTPs, but elevated dNTP concentrations in nonreplicating cells delay entry into S phase. Enzymes known as deoxyguanosine triphosphate triphosphohydrolases (Dgts) hydrolyze dNTPs into deoxynucleosides and triphosphates, and we propose that Dgts restrict dNTP concentrations to promote the G1 to S phase transition. We characterized a Dgt from the bacterium Caulobacter crescentus termed flagellar signaling suppressor C (fssC) to clarify the role of Dgts in cell cycle regulation. Deleting fssC increases dNTP levels and extends the G1 phase of the cell cycle. We determined that the segregation and duplication of the origin of replication (oriC) is delayed in ΔfssC, but the rate of replication elongation is unchanged. We conclude that dNTP hydrolysis by FssC promotes the initiation of DNA replication through a novel nucleotide signaling pathway. This work further establishes Dgts as important regulators of the G1 to S phase transition, and the high conservation of Dgts across all domains of life implies that Dgt-dependent cell cycle control may be widespread in both prokaryotic and eukaryotic organisms.
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Affiliation(s)
| | - David M. Stevenson
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI 53706, USA
| | - Katarzyna A. Gromek
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI 53706, USA
| | - Daniel Amador-Noguez
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI 53706, USA
| | - David M. Hershey
- Department of Bacteriology, University of Wisconsin – Madison, Madison, WI 53706, USA
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28
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Zhang C, Joseph AM, Casini L, Collier J, Badrinarayanan A, Manley S. Chromosome organization shapes replisome dynamics in Caulobacter crescentus. Nat Commun 2024; 15:3460. [PMID: 38658616 PMCID: PMC11043382 DOI: 10.1038/s41467-024-47849-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 04/15/2024] [Indexed: 04/26/2024] Open
Abstract
DNA replication in bacteria takes place on highly compacted chromosomes, where segregation, transcription, and repair must occur simultaneously. Within this dynamic environment, colocalization of sister replisomes has been observed in many bacterial species, driving the hypothesis that a physical linker may tether them together. However, replisome splitting has also been reported in many of the same species, leaving the principles behind replisome organization a long-standing puzzle. Here, by tracking the replisome β-clamp subunit in live Caulobacter crescentus, we find that rapid DNA segregation can give rise to a second focus which resembles a replisome, but does not replicate DNA. Sister replisomes can remain colocalized, or split apart to travel along DNA separately upon disruption of chromosome inter-arm alignment. Furthermore, chromosome arm-specific replication-transcription conflicts differentially modify replication speed on the two arms, facilitate the decoupling of the two replisomes. With these observations, we conclude that the dynamic chromosome organization flexibly shapes the organization of sister replisomes, and we outline principles which can help to reconcile previously conflicting models of replisome architecture.
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Affiliation(s)
- Chen Zhang
- Laboratory of Experimental Biophysics, Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Asha Mary Joseph
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | - Laurent Casini
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Justine Collier
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Anjana Badrinarayanan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | - Suliana Manley
- Laboratory of Experimental Biophysics, Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
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29
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Medici IF, Bartrolí L, Guaimas FF, Fulgenzi FR, Molina CL, Sánchez IE, Comerci DJ, Mongiardini E, Soler-Bistué A. The distinct cell physiology of Bradyrhizobium at the population and cellular level. BMC Microbiol 2024; 24:129. [PMID: 38643099 PMCID: PMC11031950 DOI: 10.1186/s12866-024-03272-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 03/22/2024] [Indexed: 04/22/2024] Open
Abstract
The α-Proteobacteria belonging to Bradyrhizobium genus are microorganisms of extreme slow growth. Despite their extended use as inoculants in soybean production, their physiology remains poorly characterized. In this work, we produced quantitative data on four different isolates: B. diazoefficens USDA110, B. diazoefficiens USDA122, B. japonicum E109 and B. japonicum USDA6 which are representative of specific genomic profiles. Notably, we found conserved physiological traits conserved in all the studied isolates: (i) the lag and initial exponential growth phases display cell aggregation; (ii) the increase in specific nutrient concentration such as yeast extract and gluconate hinders growth; (iii) cell size does not correlate with culture age; and (iv) cell cycle presents polar growth. Meanwhile, fitness, cell size and in vitro growth widely vary across isolates correlating to ribosomal RNA operon number. In summary, this study provides novel empirical data that enriches the comprehension of the Bradyrhizobium (slow) growth dynamics and cell cycle.
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Affiliation(s)
- Ian F Medici
- Instituto de Investigaciones Biotecnológicas, IIB-IIBIO, Universidad Nacional de San Martín- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. 25 de Mayo y Francia CP (1650), San Martín, Prov. de Buenos Aires, Argentina
| | - Leila Bartrolí
- Instituto de Investigaciones Biotecnológicas, IIB-IIBIO, Universidad Nacional de San Martín- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. 25 de Mayo y Francia CP (1650), San Martín, Prov. de Buenos Aires, Argentina
| | - Francisco F Guaimas
- Instituto de Investigaciones Biotecnológicas, IIB-IIBIO, Universidad Nacional de San Martín- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. 25 de Mayo y Francia CP (1650), San Martín, Prov. de Buenos Aires, Argentina
| | - Fabiana R Fulgenzi
- Instituto de Investigaciones Biotecnológicas, IIB-IIBIO, Universidad Nacional de San Martín- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. 25 de Mayo y Francia CP (1650), San Martín, Prov. de Buenos Aires, Argentina
| | - Charo Luciana Molina
- Instituto de Investigaciones Biotecnológicas, IIB-IIBIO, Universidad Nacional de San Martín- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. 25 de Mayo y Francia CP (1650), San Martín, Prov. de Buenos Aires, Argentina
| | - Ignacio Enrique Sánchez
- Laboratorio de Fisiología de Proteínas, Facultad de Ciencias Exactas y Naturales, CONICET Instituto de Química Biológica, Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Diego J Comerci
- Instituto de Investigaciones Biotecnológicas, IIB-IIBIO, Universidad Nacional de San Martín- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. 25 de Mayo y Francia CP (1650), San Martín, Prov. de Buenos Aires, Argentina
| | - Elías Mongiardini
- Instituto de Biotecnología y Biología Molecular (IBBM), Facultad de Ciencias Exactas, UNLP y CCT-La Plata-CONICET, La Plata, Argentina
| | - Alfonso Soler-Bistué
- Instituto de Investigaciones Biotecnológicas, IIB-IIBIO, Universidad Nacional de San Martín- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. 25 de Mayo y Francia CP (1650), San Martín, Prov. de Buenos Aires, Argentina.
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30
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Zheng EJ, Valeri JA, Andrews IW, Krishnan A, Bandyopadhyay P, Anahtar MN, Herneisen A, Schulte F, Linnehan B, Wong F, Stokes JM, Renner LD, Lourido S, Collins JJ. Discovery of antibiotics that selectively kill metabolically dormant bacteria. Cell Chem Biol 2024; 31:712-728.e9. [PMID: 38029756 PMCID: PMC11031330 DOI: 10.1016/j.chembiol.2023.10.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 08/13/2023] [Accepted: 10/30/2023] [Indexed: 12/01/2023]
Abstract
There is a need to discover and develop non-toxic antibiotics that are effective against metabolically dormant bacteria, which underlie chronic infections and promote antibiotic resistance. Traditional antibiotic discovery has historically favored compounds effective against actively metabolizing cells, a property that is not predictive of efficacy in metabolically inactive contexts. Here, we combine a stationary-phase screening method with deep learning-powered virtual screens and toxicity filtering to discover compounds with lethality against metabolically dormant bacteria and favorable toxicity profiles. The most potent and structurally distinct compound without any obvious mechanistic liability was semapimod, an anti-inflammatory drug effective against stationary-phase E. coli and A. baumannii. Integrating microbiological assays, biochemical measurements, and single-cell microscopy, we show that semapimod selectively disrupts and permeabilizes the bacterial outer membrane by binding lipopolysaccharide. This work illustrates the value of harnessing non-traditional screening methods and deep learning models to identify non-toxic antibacterial compounds that are effective in infection-relevant contexts.
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Affiliation(s)
- Erica J Zheng
- Program in Chemical Biology, Harvard University, Cambridge, MA 02138, USA; Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Jacqueline A Valeri
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Ian W Andrews
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Aarti Krishnan
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Parijat Bandyopadhyay
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Melis N Anahtar
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Alice Herneisen
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, MIT, Cambridge, MA 02139, USA
| | - Fabian Schulte
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Brooke Linnehan
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Felix Wong
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jonathan M Stokes
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
| | - Lars D Renner
- Leibniz Institute of Polymer Research and the Max Bergmann Center of Biomaterials, 01062 Dresden, Germany
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, MIT, Cambridge, MA 02139, USA
| | - James J Collins
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Institute for Medical Engineering & Science, Department of Biological Engineering, and Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA; Harvard-MIT Program in Health Sciences and Technology, Cambridge, MA 02139, USA.
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31
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Herdman M, Isbilir B, von Kügelgen A, Schulze U, Wainman A, Bharat TAM. Cell cycle dependent coordination of surface layer biogenesis in Caulobacter crescentus. Nat Commun 2024; 15:3355. [PMID: 38637514 PMCID: PMC11026435 DOI: 10.1038/s41467-024-47529-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 04/04/2024] [Indexed: 04/20/2024] Open
Abstract
Surface layers (S-layers) are proteinaceous, two-dimensional paracrystalline arrays that constitute a major component of the cell envelope in many prokaryotic species. In this study, we investigated S-layer biogenesis in the bacterial model organism Caulobacter crescentus. Fluorescence microscopy revealed localised incorporation of new S-layer at the poles and mid-cell, consistent with regions of cell growth in the cell cycle. Light microscopy and electron cryotomography investigations of drug-treated bacteria revealed that localised S-layer insertion is retained when cell division is inhibited, but is disrupted upon dysregulation of MreB or lipopolysaccharide. We further uncovered that S-layer biogenesis follows new peptidoglycan synthesis and localises to regions of high cell wall turnover. Finally, correlated cryo-light microscopy and electron cryotomographic analysis of regions of S-layer insertion showed the presence of discontinuities in the hexagonal S-layer lattice, contrasting with other S-layers completed by defined symmetric defects. Our findings present insights into how C. crescentus cells form an ordered S-layer on their surface in coordination with the biogenesis of other cell envelope components.
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Affiliation(s)
- Matthew Herdman
- Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE, UK
| | - Buse Isbilir
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Andriko von Kügelgen
- Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE, UK
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Ulrike Schulze
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Alan Wainman
- Sir William Dunn School of Pathology, University of Oxford, Oxford, OX1 3RE, UK
| | - Tanmay A M Bharat
- Structural Studies Division, MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK.
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32
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Muñoz-Gutierrez V, Cornejo FA, Schmidt K, Frese CK, Halte M, Erhardt M, Elsholz AKW, Turgay K, Charpentier E. Bacillus subtilis remains translationally active after CRISPRi-mediated replication initiation arrest. mSystems 2024; 9:e0022124. [PMID: 38546227 PMCID: PMC11019786 DOI: 10.1128/msystems.00221-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 03/06/2024] [Indexed: 04/17/2024] Open
Abstract
Initiation of bacterial DNA replication takes place at the origin of replication (oriC), a region characterized by the presence of multiple DnaA boxes that serve as the binding sites for the master initiator protein DnaA. This process is tightly controlled by modulation of the availability or activity of DnaA and oriC during development or stress conditions. Here, we aimed to uncover the physiological and molecular consequences of stopping replication in the model bacterium Bacillus subtilis. We successfully arrested replication in B. subtilis by employing a clustered regularly interspaced short palindromic repeats interference (CRISPRi) approach to specifically target the key DnaA boxes 6 and 7, preventing DnaA binding to oriC. In this way, other functions of DnaA, such as a transcriptional regulator, were not significantly affected. When replication initiation was halted by this specific artificial and early blockage, we observed that non-replicating cells continued translation and cell growth, and the initial replication arrest did not induce global stress conditions such as the SOS response.IMPORTANCEAlthough bacteria constantly replicate under laboratory conditions, natural environments expose them to various stresses such as lack of nutrients, high salinity, and pH changes, which can trigger non-replicating states. These states can enable bacteria to (i) become tolerant to antibiotics (persisters), (ii) remain inactive in specific niches for an extended period (dormancy), and (iii) adjust to hostile environments. Non-replicating states have also been studied because of the possibility of repurposing energy for the production of additional metabolites or proteins. Using clustered regularly interspaced short palindromic repeats interference (CRISPRi) targeting bacterial replication initiation sequences, we were able to successfully control replication initiation in Bacillus subtilis. This precise approach makes it possible to study non-replicating phenotypes, contributing to a better understanding of bacterial adaptive strategies.
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Affiliation(s)
- Vanessa Muñoz-Gutierrez
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
- Institute of Microbiology, Leibniz Universität Hannover, Hannover, Germany
| | | | - Katja Schmidt
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
| | | | - Manuel Halte
- Humboldt-Universität zu Berlin, Institute of Biology – Molecular Microbiology, Berlin, Germany
| | - Marc Erhardt
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
- Humboldt-Universität zu Berlin, Institute of Biology – Molecular Microbiology, Berlin, Germany
| | | | - Kürşad Turgay
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
- Institute of Microbiology, Leibniz Universität Hannover, Hannover, Germany
| | - Emmanuelle Charpentier
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
- Institute of Biology, Humboldt-Universität zu Berlin, Berlin, Germany
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33
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Tyson J, Radford P, Lambert C, Till R, Huwiler SG, Lovering AL, Elizabeth Sockett R. Prey killing without invasion by Bdellovibrio bacteriovorus defective for a MIDAS-family adhesin. Nat Commun 2024; 15:3078. [PMID: 38594280 PMCID: PMC11003981 DOI: 10.1038/s41467-024-47412-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 03/27/2024] [Indexed: 04/11/2024] Open
Abstract
The bacterium Bdellovibrio bacteriovorus is a predator of other Gram-negative bacteria. The predator invades the prey's periplasm and modifies the prey's cell wall, forming a rounded killed prey, or bdelloplast, containing a live B. bacteriovorus. Redundancy in adhesive processes makes invasive mutants rare. Here, we identify a MIDAS adhesin family protein, Bd0875, that is expressed at the predator-prey invasive junction and is important for successful invasion of prey. A mutant strain lacking bd0875 is still able to form round, dead bdelloplasts; however, 10% of the bdelloplasts do not contain B. bacteriovorus, indicative of an invasion defect. Bd0875 activity requires the conserved MIDAS motif, which is linked to catch-and-release activity of MIDAS proteins in other organisms. A proteomic analysis shows that the uninvaded bdelloplasts contain B. bacteriovorus proteins, which are likely secreted into the prey by the Δbd0875 predator during an abortive invasion period. Thus, secretion of proteins into the prey seems to be sufficient for prey killing, even in the absence of a live predator inside the prey periplasm.
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Affiliation(s)
- Jess Tyson
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK
- Chain Biotechnology Ltd, MediCity, D6 Thane Road, Nottingham, NG90 6BH, UK
| | - Paul Radford
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Carey Lambert
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK
- Biodiscovery Institute, University of Nottingham, Coates Road, Nottingham, NG7 2RD, UK
| | - Rob Till
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK
- Biodiscovery Institute, University of Nottingham, Coates Road, Nottingham, NG7 2RD, UK
| | - Simona G Huwiler
- Department of Plant & Microbial Biology, University of Zurich, CH-, 8057, Zurich, Switzerland
| | - Andrew L Lovering
- School of Biosciences, University of Birmingham, Birmingham, B15 2TT, UK.
| | - R Elizabeth Sockett
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
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34
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Delgadillo-Guevara M, Halte M, Erhardt M, Popp PF. Fluorescent tools for the standardized work in Gram-negative bacteria. J Biol Eng 2024; 18:25. [PMID: 38589953 PMCID: PMC11003136 DOI: 10.1186/s13036-024-00420-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 03/18/2024] [Indexed: 04/10/2024] Open
Abstract
Standardized and thoroughly characterized genetic tools are a prerequisite for studying cellular processes to ensure the reusability and consistency of experimental results. The discovery of fluorescent proteins (FPs) represents a milestone in the development of genetic reporters for monitoring transcription or protein localization in vivo. FPs have revolutionized our understanding of cellular dynamics by enabling the real-time visualization and tracking of biological processes. Despite these advancements, challenges remain in the appropriate use of FPs, specifically regarding their proper application, protein turnover dynamics, and the undesired disruption of cellular functions. Here, we systematically compared a comprehensive set of 15 FPs and assessed their performance in vivo by focusing on key parameters, such as signal over background ratios and protein stability rates, using the Gram-negative model organism Salmonella enterica as a representative host. We evaluated four protein degradation tags in both plasmid- and genome-based systems and our findings highlight the necessity of introducing degradation tags to analyze time-sensitive cellular processes. We demonstrate that the gain of dynamics mediated by the addition of degradation tags impacts the cell-to-cell heterogeneity of plasmid-based but not genome-based reporters. Finally, we probe the applicability of FPs for protein localization studies in living cells using standard and super-resolution fluorescence microscopy. In summary, our study underscores the importance of careful FP selection and paves the way for the development of improved genetic reporters to enhance the reproducibility and reliability of fluorescence-based research in Gram-negative bacteria and beyond.
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Affiliation(s)
- Mario Delgadillo-Guevara
- Institute of Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, 10115, Germany
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Manuel Halte
- Institute of Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, 10115, Germany
| | - Marc Erhardt
- Institute of Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, 10115, Germany
- Max Planck Unit for the Science of Pathogens, Berlin, 10117, Germany
| | - Philipp F Popp
- Institute of Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, 10115, Germany.
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35
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Lux J, Portmann H, Sánchez García L, Erhardt M, Holivololona L, Laloli L, Licheri MF, Gallay C, Hoepner R, Croucher NJ, Straume D, Veening JW, Dijkman R, Heller M, Grandgirard D, Leib SL, Hathaway LJ. Klebsiella pneumoniae peptide hijacks a Streptococcus pneumoniae permease to subvert pneumococcal growth and colonization. Commun Biol 2024; 7:425. [PMID: 38589539 PMCID: PMC11001997 DOI: 10.1038/s42003-024-06113-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 03/26/2024] [Indexed: 04/10/2024] Open
Abstract
Treatment of pneumococcal infections is limited by antibiotic resistance and exacerbation of disease by bacterial lysis releasing pneumolysin toxin and other inflammatory factors. We identified a previously uncharacterized peptide in the Klebsiella pneumoniae secretome, which enters Streptococcus pneumoniae via its AmiA-AliA/AliB permease. Subsequent downregulation of genes for amino acid biosynthesis and peptide uptake was associated with reduction of pneumococcal growth in defined medium and human cerebrospinal fluid, irregular cell shape, decreased chain length and decreased genetic transformation. The bacteriostatic effect was specific to S. pneumoniae and Streptococcus pseudopneumoniae with no effect on Streptococcus mitis, Haemophilus influenzae, Staphylococcus aureus or K. pneumoniae. Peptide sequence and length were crucial to growth suppression. The peptide reduced pneumococcal adherence to primary human airway epithelial cell cultures and colonization of rat nasopharynx, without toxicity. We identified a peptide with potential as a therapeutic for pneumococcal diseases suppressing growth of multiple clinical isolates, including antibiotic resistant strains, while avoiding bacterial lysis and dysbiosis.
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Affiliation(s)
- Janine Lux
- Faculty of Medicine, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Hannah Portmann
- Faculty of Medicine, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Lucía Sánchez García
- Faculty of Medicine, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Maria Erhardt
- Faculty of Medicine, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Lalaina Holivololona
- Faculty of Medicine, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Laura Laloli
- Faculty of Medicine, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Manon F Licheri
- Faculty of Medicine, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Clement Gallay
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Robert Hoepner
- Department of Neurology, Bern University Hospital and University of Bern, Bern, Switzerland
| | - Nicholas J Croucher
- MRC Centre for Global Infectious Disease Analysis, Sir Michael Uren Hub, White City Campus, Imperial College London, London, UK
| | - Daniel Straume
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, 1430, Ås, Norway
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Ronald Dijkman
- Faculty of Medicine, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Manfred Heller
- Proteomics and Mass Spectrometry Core Facility, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Denis Grandgirard
- Faculty of Medicine, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Stephen L Leib
- Faculty of Medicine, Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Lucy J Hathaway
- Faculty of Medicine, Institute for Infectious Diseases, University of Bern, Bern, Switzerland.
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36
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Mallikaarachchi KS, Huang JL, Madras S, Cuellar RA, Huang Z, Gega A, Rathnayaka-Mudiyanselage IW, Al-Husini N, Saldaña-Rivera N, Ma LH, Ng E, Chen JC, Schrader JM. Sinorhizobium meliloti BR-bodies promote fitness during host colonization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.05.588320. [PMID: 38617242 PMCID: PMC11014517 DOI: 10.1101/2024.04.05.588320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Biomolecular condensates, such as the nucleoli or P-bodies, are non-membrane-bound assemblies of proteins and nucleic acids that facilitate specific cellular processes. Like eukaryotic P-bodies, the recently discovered bacterial ribonucleoprotein bodies (BR-bodies) organize the mRNA decay machinery, yet the similarities in molecular and cellular functions across species have been poorly explored. Here, we examine the functions of BR-bodies in the nitrogen-fixing endosymbiont Sinorhizobium meliloti, which colonizes the roots of compatible legume plants. Assembly of BR-bodies into visible foci in S. meliloti cells requires the C-terminal intrinsically disordered region (IDR) of RNase E, and foci fusion is readily observed in vivo, suggesting they are liquid-like condensates that form via mRNA sequestration. Using Rif-seq to measure mRNA lifetimes, we found a global slowdown in mRNA decay in a mutant deficient in BR-bodies, indicating that compartmentalization of the degradation machinery promotes efficient mRNA turnover. While BR-bodies are constitutively present during exponential growth, the abundance of BR-bodies increases upon cell stress, whereby they promote stress resistance. Finally, using Medicago truncatula as host, we show that BR-bodies enhance competitiveness during colonization and appear to be required for effective symbiosis, as mutants without BR-bodies failed to stimulate plant growth. These results suggest that BR-bodies provide a fitness advantage for bacteria during infection, perhaps by enabling better resistance against the host immune response.
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Affiliation(s)
| | | | | | - Rodrigo A. Cuellar
- Department of Biology, San Francisco State University
- Current affiliation: University of Wisconsin, Madison
| | | | - Alisa Gega
- Department of Biological Sciences, Wayne State University
- Current affiliation: University of Toledo Medical School, Toledo
| | | | | | | | - Loi H. Ma
- Department of Biology, San Francisco State University
| | - Eric Ng
- Department of Biology, San Francisco State University
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37
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Thongchol J, Yu Z, Harb L, Lin Y, Koch M, Theodore M, Narsaria U, Shaevitz J, Gitai Z, Wu Y, Zhang J, Zeng L. Removal of Pseudomonas type IV pili by a small RNA virus. Science 2024; 384:eadl0635. [PMID: 38574145 PMCID: PMC11126211 DOI: 10.1126/science.adl0635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 02/29/2024] [Indexed: 04/06/2024]
Abstract
The retractile type IV pilus (T4P) is important for virulence of the opportunistic human pathogen Pseudomonas aeruginosa. The single-stranded RNA (ssRNA) phage PP7 binds to T4P and is brought to the cell surface through pilus retraction. Using fluorescence microscopy, we discovered that PP7 detaches T4P, which impairs cell motility and restricts the pathogen's virulence. Using cryo-electron microscopy, mutagenesis, optical trapping, and Langevin dynamics simulation, we resolved the structure of PP7, T4P, and the PP7/T4P complex and showed that T4P detachment is driven by the affinity between the phage maturation protein and its bound pilin, plus the pilus retraction force and speed, and pilus bending. Pilus detachment may be widespread among other ssRNA phages and their retractile pilus systems and offers new prospects for antibacterial prophylaxis and therapeutics.
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Affiliation(s)
- Jirapat Thongchol
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
- Center for Phage Technology, Texas A&M University, College Station, TX 77843, USA
| | - Zihao Yu
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
- Center for Phage Technology, Texas A&M University, College Station, TX 77843, USA
| | - Laith Harb
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
- Center for Phage Technology, Texas A&M University, College Station, TX 77843, USA
| | - Yiruo Lin
- Department of Computer Science and Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Matthias Koch
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
- Joseph Henry Laboratories of Physics, Princeton University, Princeton, NJ 08544, USA
- Department of Biology, Texas A&M University, College Station, TX 77843, USA
| | - Matthew Theodore
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
- Center for Phage Technology, Texas A&M University, College Station, TX 77843, USA
| | - Utkarsh Narsaria
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
- Center for Phage Technology, Texas A&M University, College Station, TX 77843, USA
| | - Joshua Shaevitz
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
- Joseph Henry Laboratories of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Zemer Gitai
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Yinghao Wu
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, NY 10461, USA
| | - Junjie Zhang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
- Center for Phage Technology, Texas A&M University, College Station, TX 77843, USA
| | - Lanying Zeng
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA
- Center for Phage Technology, Texas A&M University, College Station, TX 77843, USA
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38
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Alvarado Obando M, Rey-Varela D, Cava F, Dörr T. Genetic interaction mapping reveals functional relationships between peptidoglycan endopeptidases and carboxypeptidases. PLoS Genet 2024; 20:e1011234. [PMID: 38598601 PMCID: PMC11034669 DOI: 10.1371/journal.pgen.1011234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 04/22/2024] [Accepted: 03/25/2024] [Indexed: 04/12/2024] Open
Abstract
Peptidoglycan (PG) is the main component of the bacterial cell wall; it maintains cell shape while protecting the cell from internal osmotic pressure and external environmental challenges. PG synthesis is essential for bacterial growth and survival, and a series of PG modifications are required to allow expansion of the sacculus. Endopeptidases (EPs), for example, cleave the crosslinks between adjacent PG strands to allow the incorporation of newly synthesized PG. EPs are collectively essential for bacterial growth and must likely be carefully regulated to prevent sacculus degradation and cell death. However, EP regulation mechanisms are poorly understood. Here, we used TnSeq to uncover novel EP regulators in Vibrio cholerae. This screen revealed that the carboxypeptidase DacA1 (PBP5) alleviates EP toxicity. dacA1 is essential for viability on LB medium, and this essentiality was suppressed by EP overexpression, revealing that EP toxicity both mitigates, and is mitigated by, a defect in dacA1. A subsequent suppressor screen to restore viability of ΔdacA1 in LB medium identified hypomorphic mutants in the PG synthesis pathway, as well as mutations that promote EP activation. Our data thus reveal a more complex role of DacA1 in maintaining PG homeostasis than previously assumed.
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Affiliation(s)
- Manuela Alvarado Obando
- Department of Microbiology, Cornell University, Ithaca, New York, United States of America
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America
| | - Diego Rey-Varela
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Center for Microbial Research (UCMR), Science for Life Laboratory (SciLifeLab), Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Felipe Cava
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Center for Microbial Research (UCMR), Science for Life Laboratory (SciLifeLab), Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Tobias Dörr
- Department of Microbiology, Cornell University, Ithaca, New York, United States of America
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America
- Cornell Institute for Host-Microbe Interactions and Disease (CIHMID), Ithaca, New York, United States of America
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39
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Patterson B, Dinkele R, Gessner S, Koch A, Hoosen Z, January V, Leonard B, McKerry A, Seldon R, Vazi A, Hermans S, Cobelens F, Warner DF, Wood R. Aerosolization of viable Mycobacterium tuberculosis bacilli by tuberculosis clinic attendees independent of sputum-Xpert Ultra status. Proc Natl Acad Sci U S A 2024; 121:e2314813121. [PMID: 38470917 PMCID: PMC10962937 DOI: 10.1073/pnas.2314813121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 02/01/2024] [Indexed: 03/14/2024] Open
Abstract
Potential Mycobacterium tuberculosis (Mtb) transmission during different pulmonary tuberculosis (TB) disease states is poorly understood. We quantified viable aerosolized Mtb from TB clinic attendees following diagnosis and through six months' follow-up thereafter. Presumptive TB patients (n=102) were classified by laboratory, radiological, and clinical features into Group A: Sputum-Xpert Ultra-positive TB (n=52), Group B: Sputum-Xpert Ultra-negative TB (n=20), or Group C: TB undiagnosed (n=30). All groups were assessed for Mtb bioaerosol release at baseline, and subsequently at 2 wk, 2 mo, and 6 mo. Groups A and B were notified to the national TB program and received standard anti-TB chemotherapy; Mtb was isolated from 92% and 90% at presentation, 87% and 74% at 2 wk, 54% and 44% at 2 mo and 32% and 20% at 6 mo, respectively. Surprisingly, similar numbers were detected in Group C not initiating TB treatment: 93%, 70%, 48% and 22% at the same timepoints. A temporal association was observed between Mtb bioaerosol release and TB symptoms in all three groups. Persistence of Mtb bioaerosol positivity was observed in ~30% of participants irrespective of TB chemotherapy. Captured Mtb bacilli were predominantly acid-fast stain-negative and poorly culturable; however, three bioaerosol samples yielded sufficient biomass following culture for whole-genome sequencing, revealing two different Mtb lineages. Detection of viable aerosolized Mtb in clinic attendees, independent of TB diagnosis, suggests that unidentified Mtb transmitters might contribute a significant attributable proportion of community exposure. Additional longitudinal studies with sputum culture-positive and -negative control participants are required to investigate this possibility.
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Affiliation(s)
- Benjamin Patterson
- Amsterdam Institute for Global Health and Development, University of Amsterdam, Amsterdam1105, The Netherlands
| | - Ryan Dinkele
- South African Medical Research Council, National Health Laboratory Service, University of Cape Town Molecular Mycobacteriology Research Unit & Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town7925, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town7925, South Africa
| | - Sophia Gessner
- South African Medical Research Council, National Health Laboratory Service, University of Cape Town Molecular Mycobacteriology Research Unit & Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town7925, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town7925, South Africa
| | - Anastasia Koch
- South African Medical Research Council, National Health Laboratory Service, University of Cape Town Molecular Mycobacteriology Research Unit & Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town7925, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town7925, South Africa
| | - Zeenat Hoosen
- Aerobiology and TB Research Unit, Desmond Tutu Health Foundation, Cape Town7975, South Africa
| | - Vanessa January
- Aerobiology and TB Research Unit, Desmond Tutu Health Foundation, Cape Town7975, South Africa
| | - Bryan Leonard
- Aerobiology and TB Research Unit, Desmond Tutu Health Foundation, Cape Town7975, South Africa
| | - Andrea McKerry
- Aerobiology and TB Research Unit, Desmond Tutu Health Foundation, Cape Town7975, South Africa
| | - Ronnett Seldon
- Aerobiology and TB Research Unit, Desmond Tutu Health Foundation, Cape Town7975, South Africa
| | - Andiswa Vazi
- Aerobiology and TB Research Unit, Desmond Tutu Health Foundation, Cape Town7975, South Africa
| | - Sabine Hermans
- Amsterdam Institute for Global Health and Development, University of Amsterdam, Amsterdam1105, The Netherlands
| | - Frank Cobelens
- Amsterdam Institute for Global Health and Development, University of Amsterdam, Amsterdam1105, The Netherlands
| | - Digby F. Warner
- South African Medical Research Council, National Health Laboratory Service, University of Cape Town Molecular Mycobacteriology Research Unit & Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical TB Research, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town7925, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town7925, South Africa
- Wellcome Centre for Infectious Diseases Research in Africa, Faculty of Health Sciences, University of Cape Town, Cape Town7925, South Africa
| | - Robin Wood
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town7925, South Africa
- Aerobiology and TB Research Unit, Desmond Tutu Health Foundation, Cape Town7975, South Africa
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40
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Zhang Y, Wang X, Odesanmi C, Hu Q, Li D, Tang Y, Liu Z, Mi J, Liu S, Wen T. Model-guided metabolic rewiring to bypass pyruvate oxidation for pyruvate derivative synthesis by minimizing carbon loss. mSystems 2024; 9:e0083923. [PMID: 38315666 PMCID: PMC10949502 DOI: 10.1128/msystems.00839-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 01/08/2024] [Indexed: 02/07/2024] Open
Abstract
Engineering microbial hosts to synthesize pyruvate derivatives depends on blocking pyruvate oxidation, thereby causing severe growth defects in aerobic glucose-based bioprocesses. To decouple pyruvate metabolism from cell growth to improve pyruvate availability, a genome-scale metabolic model combined with constraint-based flux balance analysis, geometric flux balance analysis, and flux variable analysis was used to identify genetic targets for strain design. Using translation elements from a ~3,000 cistronic library to modulate fxpK expression in a bicistronic cassette, a bifido shunt pathway was introduced to generate three molecules of non-pyruvate-derived acetyl-CoA from one molecule of glucose, bypassing pyruvate oxidation and carbon dioxide generation. The dynamic control of flux distribution by T7 RNAP-mediated synthetic small RNA decoupled pyruvate catabolism from cell growth. Adaptive laboratory evolution and multi-omics analysis revealed that a mutated isocitrate dehydrogenase functioned as a metabolic switch to activate the glyoxylate shunt as the only C4 anaplerotic pathway to generate malate from two molecules of acetyl-CoA input and bypass two decarboxylation reactions in the tricarboxylic acid cycle. A chassis strain for pyruvate derivative synthesis was constructed to reduce carbon loss by using the glyoxylate shunt as the only C4 anaplerotic pathway and the bifido shunt as a non-pyruvate-derived acetyl-CoA synthetic pathway and produced 22.46, 27.62, and 6.28 g/L of l-leucine, l-alanine, and l-valine by a controlled small RNA switch, respectively. Our study establishes a novel metabolic pattern of glucose-grown bacteria to minimize carbon loss under aerobic conditions and provides valuable insights into cell design for manufacturing pyruvate-derived products.IMPORTANCEBio-manufacturing from biomass-derived carbon sources using microbes as a cell factory provides an eco-friendly alternative to petrochemical-based processes. Pyruvate serves as a crucial building block for the biosynthesis of industrial chemicals; however, it is different to improve pyruvate availability in vivo due to the coupling of pyruvate-derived acetyl-CoA with microbial growth and energy metabolism via the oxidative tricarboxylic acid cycle. A genome-scale metabolic model combined with three algorithm analyses was used for strain design. Carbon metabolism was reprogrammed using two genetic control tools to fine-tune gene expression. Adaptive laboratory evolution and multi-omics analysis screened the growth-related regulatory targets beyond rational design. A novel metabolic pattern of glucose-grown bacteria is established to maintain growth fitness and minimize carbon loss under aerobic conditions for the synthesis of pyruvate-derived products. This study provides valuable insights into the design of a microbial cell factory for synthetic biology to produce industrial bio-products of interest.
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Affiliation(s)
- Yun Zhang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xueliang Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Christianah Odesanmi
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Qitiao Hu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Dandan Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yuan Tang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Zhe Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jie Mi
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Shuwen Liu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Tingyi Wen
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
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41
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Steemans B, Govers SK. Protocol to train a support vector machine for the automatic curation of bacterial cell detections in microscopy images. STAR Protoc 2024; 5:102868. [PMID: 38308840 PMCID: PMC10850855 DOI: 10.1016/j.xpro.2024.102868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/10/2024] [Accepted: 01/17/2024] [Indexed: 02/05/2024] Open
Abstract
Manual curation of bacterial cell detections in microscopy images remains a time-consuming and laborious task. This work offers a comprehensive, step-by-step tutorial on training a support vector machine to autonomously distinguish between good and bad cell detections. Jupyter notebooks are included to perform feature extraction, labeling, and training of the machine learning model. This method can readily be incorporated into profiling pipelines aimed at extracting a multitude of features across large collections of individual cells, strains, and species. For complete details on the use and execution of this protocol, please refer to Govers et al.1.
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Affiliation(s)
- Bart Steemans
- Department of Biology, KU Leuven, 3001 Leuven, Belgium
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Castro-Falcón G, Straetener J, Bornikoel J, Reimer D, Purdy TN, Berscheid A, Schempp FM, Liu DY, Linington RG, Brötz-Oesterhelt H, Hughes CC. Antibacterial Marinopyrroles and Pseudilins Act as Protonophores. ACS Chem Biol 2024; 19:743-752. [PMID: 38377384 PMCID: PMC10949930 DOI: 10.1021/acschembio.3c00773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 12/27/2023] [Indexed: 02/22/2024]
Abstract
Elucidating the mechanism of action (MoA) of antibacterial natural products is crucial to evaluating their potential as novel antibiotics. Marinopyrroles, pentachloropseudilin, and pentabromopseudilin are densely halogenated, hybrid pyrrole-phenol natural products with potent activity against Gram-positive bacterial pathogens like Staphylococcus aureus. However, the exact way they exert this antibacterial activity has not been established. In this study, we explore their structure-activity relationship, determine their spatial location in bacterial cells, and investigate their MoA. We show that the natural products share a common MoA based on membrane depolarization and dissipation of the proton motive force (PMF) that is essential for cell viability. The compounds show potent protonophore activity but do not appear to destroy the integrity of the cytoplasmic membrane via the formation of larger pores or interfere with the stability of the peptidoglycan sacculus. Thus, our current model for the antibacterial MoA of marinopyrrole, pentachloropseudilin, and pentabromopseudilin stipulates that the acidic compounds insert into the membrane and transport protons inside the cell. This MoA may explain many of the deleterious biological effects in mammalian cells, plants, phytoplankton, viruses, and protozoans that have been reported for these compounds.
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Affiliation(s)
- Gabriel Castro-Falcón
- Center
for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, California 92093, United States
| | - Jan Straetener
- Department
of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology
and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
| | - Jan Bornikoel
- Department
of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology
and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
| | - Daniela Reimer
- Center
for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, California 92093, United States
| | - Trevor N. Purdy
- Center
for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, California 92093, United States
| | - Anne Berscheid
- Department
of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology
and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
| | - Florence M. Schempp
- Center
for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, California 92093, United States
| | - Dennis Y. Liu
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Roger G. Linington
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Heike Brötz-Oesterhelt
- Department
of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology
and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
- Cluster
of Excellence EXC 2124: Controlling Microbes to Fight Infection, University of Tübingen, Tübingen 72076, Germany
- German
Center for Infection Research, Partner Site Tübingen, Tübingen 72076, Germany
| | - Chambers C. Hughes
- Center
for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, California 92093, United States
- Department
of Microbial Bioactive Compounds, Interfaculty Institute of Microbiology
and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
- Cluster
of Excellence EXC 2124: Controlling Microbes to Fight Infection, University of Tübingen, Tübingen 72076, Germany
- German
Center for Infection Research, Partner Site Tübingen, Tübingen 72076, Germany
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Bollinger KW, Müh U, Ocius KL, Apostolos AJ, Pires MM, Helm RF, Popham DL, Weiss DS, Ellermeier CD. Identification of a new family of peptidoglycan transpeptidases reveals atypical crosslinking is essential for viability in Clostridioides difficile. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.14.584917. [PMID: 38559057 PMCID: PMC10980060 DOI: 10.1101/2024.03.14.584917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Clostridioides difficile, the leading cause of antibiotic-associated diarrhea, relies primarily on 3-3 crosslinks created by L,D-transpeptidases (LDTs) to fortify its peptidoglycan (PG) cell wall. This is unusual, as in most bacteria the vast majority of PG crosslinks are 4-3 crosslinks, which are created by penicillin-binding proteins (PBPs). Here we report the unprecedented observation that 3-3 crosslinking is essential for viability in C. difficile. We also report the discovery of a new family of LDTs that use a VanW domain to catalyze 3-3 crosslinking rather than a YkuD domain as in all previously known LDTs. Bioinformatic analyses indicate VanW domain LDTs are less common than YkuD domain LDTs and are largely restricted to Gram-positive bacteria. Our findings suggest that LDTs might be exploited as targets for antibiotics that kill C. difficile without disrupting the intestinal microbiota that is important for keeping C. difficile in check.
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Affiliation(s)
- Kevin W. Bollinger
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Ute Müh
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Karl L. Ocius
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - Alexis J. Apostolos
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
- Present address: Haleon, 1211 Sherwood Ave, Richmond, VA 23220
| | - Marcos M. Pires
- Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - Richard F. Helm
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA
| | - David L. Popham
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - David S. Weiss
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
- Graduate Program in Genetics, University of Iowa, Iowa City, IA USA
| | - Craig D. Ellermeier
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
- Graduate Program in Genetics, University of Iowa, Iowa City, IA USA
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VanOtterloo LM, Macias LA, Powers MJ, Brodbelt JS, Trent MS. Characterization of Acinetobacter baumannii core oligosaccharide synthesis reveals novel aspects of lipooligosaccharide assembly. mBio 2024; 15:e0301323. [PMID: 38349180 PMCID: PMC10936431 DOI: 10.1128/mbio.03013-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 01/12/2024] [Indexed: 03/14/2024] Open
Abstract
A fundamental feature of Gram-negative bacteria is their outer membrane that protects the cell against environmental stressors. This defense is predominantly due to its asymmetry, with glycerophospholipids located in the inner leaflet and lipopolysaccharide (LPS) or lipooligosaccharide (LOS) confined to the outer leaflet. LPS consists of a lipid A anchor, a core oligosaccharide, and a distal O-antigen while LOS lacks O-antigen. While LPS/LOS is typically essential for growth, this is not the case for Acinetobacter baumannii. Despite this unique property, the synthesis of the core oligosaccharide of A. baumannii LOS is not well-described. Here, we characterized the LOS chemotypes of A. baumannii strains with mutations in a predicted core oligosaccharide locus via tandem mass spectrometry. This allowed for an extensive identification of genes required for core assembly that can be exploited to generate precise structural LOS modifications in many A. baumannii strains. We further investigated two chemotypically identical yet phenotypically distinct mutants, ∆2903 and ∆lpsB, that exposed a possible link between LOS and the peptidoglycan cell wall-two cell envelope components whose coordination has not yet been described in A. baumannii. Selective reconstruction of the core oligosaccharide via expression of 2903 and LpsB revealed that these proteins rely on each other for the unusual tandem transfer of two residues, KdoIII and N-acetylglucosaminuronic acid. The data presented not only allow for better usage of A. baumannii as a tool to study outer membrane integrity but also provide further evidence for a novel mechanism of core oligosaccharide assembly. IMPORTANCE Acinetobacter baumannii is a multidrug-resistant pathogen that produces lipooligosaccharide (LOS), a glycolipid that confers protective asymmetry to the bacterial outer membrane. The core oligosaccharide is a ubiquitous component of LOS that typically follows a well-established model of synthesis. In addition to providing an extensive analysis of the genes involved in the synthesis of the core region, we demonstrate that this organism has evidently diverged from the long-held archetype of core synthesis. Moreover, our data suggest that A. baumannii LOS assembly is important for cell division and likely intersects with the synthesis of the peptidoglycan cell wall, another essential component of the Gram-negative cell envelope. This connection between LOS and cell wall synthesis provides an intriguing foundation for a unique method of outer membrane biogenesis and cell envelope coordination.
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Affiliation(s)
- Leah M. VanOtterloo
- Department of Microbiology, College of Art and Sciences, University of Georgia, Athens, Georgia, USA
| | - Luis A. Macias
- Department of Chemistry, University of Texas at Austin, Austin, Texas, USA
| | - Matthew J. Powers
- Department of Microbiology, College of Art and Sciences, University of Georgia, Athens, Georgia, USA
| | | | - M. Stephen Trent
- Department of Microbiology, College of Art and Sciences, University of Georgia, Athens, Georgia, USA
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
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Halte M, Andrianova EP, Goosmann C, Chevance FFV, Hughes KT, Zhulin IB, Erhardt M. FlhE functions as a chaperone to prevent formation of periplasmic flagella in Gram-negative bacteria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.11.584431. [PMID: 38558991 PMCID: PMC10979839 DOI: 10.1101/2024.03.11.584431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The bacterial flagellum is an organelle utilized by many Gram-negative bacteria to facilitate motility. The flagellum is composed of a several µm long, extracellular filament that is connected to a cytoplasmic rotor-stator complex via a periplasmic rod. Composed of ∼20 structural proteins, ranging from a few subunits to several thousand building blocks, the flagellum is a paradigm of a complex macromolecular structure that utilizes a highly regulated assembly process. This process is governed by multiple checkpoints that ensure an ordered gene expression pattern coupled to the assembly of the various flagellar building blocks in order to produce a functional flagellum. Using epifluorescence, super-resolution STED and transmission electron microscopy, we discovered that in Salmonella , the absence of one periplasmic protein, FlhE, prevents proper flagellar morphogenesis and results in the formation of periplasmic flagella. The periplasmic flagella disrupt cell wall synthesis, leading to a loss of the standard cell morphology resulting in cell lysis. We propose a model where FlhE functions as a periplasmic chaperone to control assembly of the periplasmic rod to prevent formation of periplasmic flagella. Our results highlight that bacteria evolved sophisticated regulatory mechanisms to control proper flagellar assembly and minor deviations from this highly regulated process can cause dramatic physiological consequences.
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Wurzbacher CE, Haufschild T, Hammer J, van Teeseling MCF, Kallscheuer N, Jogler C. Planctoellipticum variicoloris gen. nov., sp. nov., a novel member of the family Planctomycetaceae isolated from wastewater of the aeration lagoon of a sugar processing plant in Northern Germany. Sci Rep 2024; 14:5741. [PMID: 38459238 PMCID: PMC10923784 DOI: 10.1038/s41598-024-56373-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 03/05/2024] [Indexed: 03/10/2024] Open
Abstract
In the present study, we characterise a strain isolated from the wastewater aeration lagoon of a sugar processing plant in Schleswig (Northern Germany) by Heinz Schlesner. As a pioneer in planctomycetal research, he isolated numerous strains belonging to the phylum Planctomycetota from aquatic habitats around the world. Phylogenetic analyses show that strain SH412T belongs to the family Planctomycetaceae and shares with 91.6% the highest 16S rRNA gene sequence similarity with Planctopirus limnophila DSM 3776T. Its genome has a length of 7.3 Mb and a G + C content of 63.6%. Optimal growth of strain SH412T occurs at pH 7.0-7.5 and 28 °C with its pigmentation depending on sunlight exposure. Strain SH412T reproduces by polar asymmetric division ("budding") and forms ovoid cells. The cell size determination was performed using a semi-automatic pipeline, which we first evaluated with the model species P. limnophila and then applied to strain SH412T. Furthermore, the data acquired during time-lapse analyses suggests a lifestyle switch from flagellated daughter cells to non-flagellated mother cells in the subsequent cycle. Based on our data, we suggest that strain SH412T represents a novel species within a novel genus, for which we propose the name Planctoellipticum variicoloris gen. nov., sp. nov., with strain SH412T (= CECT 30430T = STH00996T, the STH number refers to the Jena Microbial Resource Collection JMRC) as the type strain of the new species.
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Affiliation(s)
- Carmen E Wurzbacher
- Department of Microbial Interactions, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Tom Haufschild
- Department of Microbial Interactions, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Jonathan Hammer
- Department of Microbial Interactions, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Muriel C F van Teeseling
- Junior Research Group "Prokaryotic Cell Biology", Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Nicolai Kallscheuer
- Department of Microbial Interactions, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Christian Jogler
- Department of Microbial Interactions, Institute of Microbiology, Friedrich Schiller University, Jena, Germany.
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Nußbaum P, Kureisaite-Ciziene D, Bellini D, van der Does C, Kojic M, Taib N, Yeates A, Tourte M, Gribaldo S, Loose M, Löwe J, Albers SV. Proteins containing photosynthetic reaction centre domains modulate FtsZ-based archaeal cell division. Nat Microbiol 2024; 9:698-711. [PMID: 38443575 DOI: 10.1038/s41564-024-01600-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 01/08/2024] [Indexed: 03/07/2024]
Abstract
Cell division in all domains of life requires the orchestration of many proteins, but in Archaea most of the machinery remains poorly characterized. Here we investigate the FtsZ-based cell division mechanism in Haloferax volcanii and find proteins containing photosynthetic reaction centre (PRC) barrel domains that play an essential role in archaeal cell division. We rename these proteins cell division protein B 1 (CdpB1) and CdpB2. Depletions and deletions in their respective genes cause severe cell division defects, generating drastically enlarged cells. Fluorescence microscopy of tagged FtsZ1, FtsZ2 and SepF in CdpB1 and CdpB2 mutant strains revealed an unusually disordered divisome that is not organized into a distinct ring-like structure. Biochemical analysis shows that SepF forms a tripartite complex with CdpB1/2 and crystal structures suggest that these two proteins might form filaments, possibly aligning SepF and the FtsZ2 ring during cell division. Overall our results indicate that PRC-domain proteins play essential roles in FtsZ-based cell division in Archaea.
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Affiliation(s)
- Phillip Nußbaum
- Molecular Biology of Archaea, Microbiology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Dom Bellini
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Chris van der Does
- Molecular Biology of Archaea, Microbiology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Marko Kojic
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Najwa Taib
- Evolutionary Biology of the Microbial Cell Laboratory, Institut Pasteur, Université Paris Cité, Paris, France
- Bioinformatics and Biostatistics Hub, Institut Pasteur, Université Paris Cité, Paris, France
| | - Anna Yeates
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Maxime Tourte
- Molecular Biology of Archaea, Microbiology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Simonetta Gribaldo
- Evolutionary Biology of the Microbial Cell Laboratory, Institut Pasteur, Université Paris Cité, Paris, France
| | - Martin Loose
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Jan Löwe
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Microbiology, Faculty of Biology, University of Freiburg, Freiburg, Germany.
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.
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Bartlett TM, Sisley TA, Mychack A, Walker S, Baker RW, Rudner DZ, Bernhardt TG. FacZ is a GpsB-interacting protein that prevents aberrant division-site placement in Staphylococcus aureus. Nat Microbiol 2024; 9:801-813. [PMID: 38443581 PMCID: PMC10914604 DOI: 10.1038/s41564-024-01607-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 01/15/2024] [Indexed: 03/07/2024]
Abstract
Staphylococcus aureus is a Gram-positive pathogen responsible for antibiotic-resistant infections. To identify vulnerabilities in cell envelope biogenesis that may overcome resistance, we enriched for S. aureus transposon mutants with defects in cell surface integrity or cell division by sorting for cells that stain with propidium iodide or have increased light-scattering properties, respectively. Transposon sequencing of the sorted populations identified more than 20 previously uncharacterized factors impacting these processes. Cells inactivated for one of these proteins, factor preventing extra Z-rings (FacZ, SAOUHSC_01855), showed aberrant membrane invaginations and multiple FtsZ cytokinetic rings. These phenotypes were suppressed in mutants lacking the conserved cell-division protein GpsB, which forms an interaction hub bridging envelope biogenesis factors with the cytokinetic ring in S. aureus. FacZ was found to interact directly with GpsB in vitro and in vivo. We therefore propose that FacZ is an envelope biogenesis factor that antagonizes GpsB function to prevent aberrant division events in S. aureus.
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Affiliation(s)
- Thomas M Bartlett
- Department of Microbiology Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Tyler A Sisley
- Department of Microbiology Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Aaron Mychack
- Department of Microbiology Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Suzanne Walker
- Department of Microbiology Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Richard W Baker
- Department of Biochemistry and Biophysics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - David Z Rudner
- Department of Microbiology Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
| | - Thomas G Bernhardt
- Department of Microbiology Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA.
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Fraikin N, Van Melderen L. Single-cell evidence for plasmid addiction mediated by toxin-antitoxin systems. Nucleic Acids Res 2024; 52:1847-1859. [PMID: 38224456 PMCID: PMC10899753 DOI: 10.1093/nar/gkae018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/22/2023] [Accepted: 01/03/2024] [Indexed: 01/16/2024] Open
Abstract
Toxin-antitoxin (TA) systems are small selfish genetic modules that increase vertical stability of their replicons. They have long been thought to stabilize plasmids by killing cells that fail to inherit a plasmid copy through a phenomenon called post-segregational killing (PSK) or addiction. While this model has been widely accepted, no direct observation of PSK was reported in the literature. Here, we devised a system that enables visualization of plasmid loss and PSK at the single-cell level using meganuclease-driven plasmid curing. Using the ccd system, we show that cells deprived of a ccd-encoding plasmid show hallmarks of DNA damage, i.e. filamentation and induction of the SOS response. Activation of ccd triggered cell death in most plasmid-free segregants, although some intoxicated cells were able to resume growth, showing that PSK-induced damage can be repaired in a SOS-dependent manner. Damage induced by ccd activates resident lambdoid prophages, which potentiate the killing effect of ccd. The loss of a model plasmid containing TA systems encoding toxins presenting various molecular mechanisms induced different morphological changes, growth arrest and loss of viability. Our experimental setup enables further studies of TA-induced phenotypes and suggests that PSK is a general mechanism for plasmid stabilization by TA systems.
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Affiliation(s)
- Nathan Fraikin
- Bacterial Genetics and Physiology, Department of Molecular Biology, Faculté des Sciences, Université Libre de Bruxelles (ULB), 6041 Gosselies, Belgium
| | - Laurence Van Melderen
- Bacterial Genetics and Physiology, Department of Molecular Biology, Faculté des Sciences, Université Libre de Bruxelles (ULB), 6041 Gosselies, Belgium
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Tran BM, Punter CM, Linnik D, Iyer A, Poolman B. Single-protein Diffusion in the Periplasm of Escherichia coli. J Mol Biol 2024; 436:168420. [PMID: 38143021 DOI: 10.1016/j.jmb.2023.168420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 12/13/2023] [Accepted: 12/19/2023] [Indexed: 12/26/2023]
Abstract
The width of the periplasmic space of Gram-negative bacteria is only about 25-30 nm along the long axis of the cell, which affects free diffusion of (macro)molecules. We have performed single-particle displacement measurements and diffusion simulation studies to determine the impact of confinement on the apparent mobility of proteins in the periplasm of Escherichia coli. The diffusion of a reporter protein and of OsmY, an osmotically regulated periplasmic protein, is characterized by a fast and slow component regardless of the osmotic conditions. The diffusion coefficient of the fast fraction increases upon osmotic upshift, in agreement with a decrease in macromolecular crowding of the periplasm, but the mobility of the slow (immobile) fraction is not affected by the osmotic stress. We observe that the confinement created by the inner and outer membranes results in a lower apparent diffusion coefficient, but this can only partially explain the slow component of diffusion in the particle displacement measurements, suggesting that a fraction of the proteins is hindered in its mobility by large periplasmic structures. Using particle-based simulations, we have determined the confinement effect on the apparent diffusion coefficient of the particles for geometries akin the periplasmic space of Gram-negative bacteria.
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Affiliation(s)
- Buu Minh Tran
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Christiaan Michiel Punter
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Dmitrii Linnik
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Aditya Iyer
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Bert Poolman
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands.
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