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Avendaño-Herrera R, Echeverría-Bugueño M, Hernández M, Saldivia P, Irgang R. Proteomic characterization of Tenacibaculum dicentrarchi under iron limitation reveals an upregulation of proteins related to iron oxidation and reduction metabolism, iron uptake systems and gliding motility. JOURNAL OF FISH DISEASES 2024; 47:e13984. [PMID: 38943549 DOI: 10.1111/jfd.13984] [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: 03/27/2024] [Revised: 05/29/2024] [Accepted: 06/04/2024] [Indexed: 07/01/2024]
Abstract
A strategy for vaccine design involves identifying proteins that could be involved in pathogen-host interactions. The aim of this proteomic study was to determine how iron limitation affects the protein expression of Tenacibaculum dicentrarchi, with a primary focus on virulence factors and proteins associated with iron uptake. The proteomic analysis was carried out using two strains of T. dicentrarchi grown under normal (control) and iron-limited conditions, mimicking the host environment. Our findings revealed differences in the proteins expressed by the type strain CECT 7612T and the Chilean strain TdCh05 of T. dicentrarchi. Nonetheless, both share a common response to iron deprivation, with an increased expression of proteins associated with iron oxidation and reduction metabolism (e.g., SufA, YpmQ, SufD), siderophore transport (e.g., ExbD, TonB-dependent receptor, HbpA), heme compound biosynthesis, and iron transporters under iron limitation. Proteins involved in gliding motility, such as GldL and SprE, were also upregulated in both strains. A negative differential regulation of metabolic proteins, particularly those associated with amino acid biosynthesis, was observed under iron limitation, reflecting the impact of iron availability on bacterial metabolism. Additionally, the TdCh05 strain exhibited unique proteins associated with gliding motility machinery and phage infection control compared to the type strain. These groups of proteins have been identified as virulence factors within the Flavobacteriaceae family, including the genus Tenacibaculum. These results build upon our previous report on iron acquisition mechanisms and could lay the groundwork for future studies aimed at elucidating the role of some of the described proteins in the infectious process of tenacibaculosis, as well as in the development of potential vaccines.
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Affiliation(s)
- Ruben Avendaño-Herrera
- Universidad Andrés Bello, Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Facultad de Ciencias de la Vida, Viña del Mar, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Viña del Mar, Chile
- Centro de Investigación Marina Quintay (CIMARQ), Universidad Andrés Bello, Quintay, Chile
| | - Macarena Echeverría-Bugueño
- Universidad Andrés Bello, Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Facultad de Ciencias de la Vida, Viña del Mar, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Viña del Mar, Chile
| | - Mauricio Hernández
- Division of Biotechnology, Molecular Epidemiology for Life of Science Research (MELISA) Institute, San Pedro de Paz, Chile
| | - Pablo Saldivia
- Division of Biotechnology, Molecular Epidemiology for Life of Science Research (MELISA) Institute, San Pedro de Paz, Chile
| | - Rute Irgang
- Universidad Andrés Bello, Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Facultad de Ciencias de la Vida, Viña del Mar, Chile
- Interdisciplinary Center for Aquaculture Research (INCAR), Viña del Mar, Chile
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Vanitshavit V, Charoenlap N, Sallabhan R, Whangsuk W, Bhinija K, Dulyayangkul P, Mongkolsuk S, Vattanavibooon P. Acquired resistance of Stenotrophomonas maltophilia to antimicrobials induced by herbicide paraquat dichloride. PLoS One 2024; 19:e0309525. [PMID: 39196988 PMCID: PMC11356428 DOI: 10.1371/journal.pone.0309525] [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: 02/14/2024] [Accepted: 08/14/2024] [Indexed: 08/30/2024] Open
Abstract
Stenotrophomonas maltophilia, a ubiquitous environmental bacterium, is an important cause of nosocomial infections. Although banned in some countries, paraquat (PQ) is commonly used to control weeds. In this study, we investigated the effects of increasing concentrations of PQ on S. maltophilia and its antimicrobial resistance. The sequential exposure of S. maltophilia K279a to increasing concentrations of PQ induces the formation of strains with increased resistance to PQ. Among the 400 PQ-resistant isolates tested, 70 clones were resistant to 16 μg/ml ciprofloxacin (CIP), and around 18% of the PQ/CIP-resistant isolates showed increased resistance to all the tested antimicrobials including, the aminoglycosides, quinolones, cephalosporin, chloramphenicol, and co-trimoxazole. The results of the expression analysis of the antimicrobial resistance genes in the five selected PQ/CIP-resistant isolates demonstrated the high expression of genes encoding efflux pumps (smeYZ, smaAB, smaCDEF, smeDEF, smeVWX, and smtcrA) and the enzymes aph(3')-IIc, blaL1, and blaL2. However, expression of the genes known for PQ resistance (i.e., mfsA and sod) were not altered relative to the wild-type levels. Whole genome sequence analysis identified gene mutations that could account for the antimicrobial resistance, namely, smeT (TetR family regulatory protein), rplA (ribosomal protein L1), and acnA (aconitase A). Ectopic expression of wild-type AcnA partially complemented the fluoroquinolone-resistant phenotype of the mutant with mutated acnA, which suggests the role of aconitase A in antimicrobial susceptibility. Exposure of S. maltophilia to PQ thus induces the development of strains that increase resistance to multiple antimicrobials.
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Affiliation(s)
| | - Nisanart Charoenlap
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, Thailand
- Center of Excellence on Environmental Health and Toxicology (EHT), OPS, MHESI, Bangkok, Thailands
| | - Ratiboot Sallabhan
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, Thailand
| | - Wirongrong Whangsuk
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, Thailand
| | - Kisana Bhinija
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, Thailand
| | | | - Skorn Mongkolsuk
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, Thailand
- Center of Excellence on Environmental Health and Toxicology (EHT), OPS, MHESI, Bangkok, Thailands
| | - Paiboon Vattanavibooon
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, Thailand
- Center of Excellence on Environmental Health and Toxicology (EHT), OPS, MHESI, Bangkok, Thailands
- Program in Applied Biological Science: Environmental Health, Chulabhorn Graduate Institute, Bangkok, Thailand
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Beaud Benyahia B, Taib N, Beloin C, Gribaldo S. Terrabacteria: redefining bacterial envelope diversity, biogenesis and evolution. Nat Rev Microbiol 2024:10.1038/s41579-024-01088-0. [PMID: 39198708 DOI: 10.1038/s41579-024-01088-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2024] [Indexed: 09/01/2024]
Abstract
The bacterial envelope is one of the oldest and most essential cellular components and has been traditionally divided into Gram-positive (monoderm) and Gram-negative (diderm). Recent landmark studies have challenged a major paradigm in microbiology by inferring that the last bacterial common ancestor had a diderm envelope and that the outer membrane (OM) was lost repeatedly in evolution to give rise to monoderms. Intriguingly, OM losses appear to have occurred exclusively in the Terrabacteria, one of the two major clades of bacteria. In this Review, we present current knowledge about the Terrabacteria. We describe their diversity and phylogeny and then highlight the vast phenotypic diversity of the Terrabacteria cell envelopes, which display large deviations from the textbook examples of diderms and monoderms, challenging the classical Gram-positive-Gram-negative divide. We highlight the striking differences in the systems involved in OM biogenesis in Terrabacteria with respect to the classical diderm experimental models and how they provide novel insights into the diversity and biogenesis of the bacterial cell envelope. We also discuss the potential evolutionary steps that might have led to the multiple losses of the OM and speculate on how the very first OM might have emerged before the last bacterial common ancestor.
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Affiliation(s)
- Basile Beaud Benyahia
- Evolutionary Biology of the Microbial Cell Laboratory, Institut Pasteur, Université Paris Cité, Paris, France
| | - 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
| | - Christophe Beloin
- Genetics of Biofilms Laboratory, Institut Pasteur, Université Paris Cité, Paris, France
| | - Simonetta Gribaldo
- Evolutionary Biology of the Microbial Cell Laboratory, Institut Pasteur, Université Paris Cité, Paris, France.
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Zhou P, Bibek GC, Hu B, Wu C. Development of SacB-based Counterselection for Efficient Allelic Exchange in Fusobacterium nucleatum. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.16.608263. [PMID: 39229080 PMCID: PMC11370447 DOI: 10.1101/2024.08.16.608263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Fusobacterium nucleatum , prevalent in the oral cavity, is significantly linked to overall human health. Our molecular comprehension of its role in oral biofilm formation and its interactions with the host under various pathological circumstances has seen considerable advancements in recent years, primarily due to the development of various genetic tools for DNA manipulation in this bacterium. Of these, counterselection-based unmarked in-frame mutation methods have proved notably effective. Under suitable growth conditions, cells carrying a counterselectable gene die, enabling efficient selection of rare defined allelic exchange mutants. The sacB gene from Bacillus subtilis , encoding levansucrase, is a widely used counterselective marker partly due to the easy availability of sucrose. Yet, its potential application in F. nucleatum genetic study remains untested. We demonstrated that F. nucleatum cells expressing sacB in either a shuttle or suicide plasmid exhibit a lethal sensitivity to supplemental sucrose. Utilizing sucrose counterselection, we created an in-frame deletion of the F. nucleatum tonB gene, a critical gene for energy-dependent transport processes in Gram-negative bacteria, and a precise knockin of the luciferase gene immediately following the stop codon of the hslO gene, the last gene of a five-gene operon possible related to the natural competence of F. nucleatum . Post counterselection with 5% sucrose, chromosomal plasmid loss occurred in all colonies, leading to gene alternations in half of the screened isolates. This sacB -based counterselection technique provides a reliable method for isolating unmarked gene mutations in wild-type F. nucleatum , enriching the toolkit for fusobacterial research. IMPORTANCE Investigations into Fusobacterium nucleatum 's role in related diseases significantly benefit from the strategies of creating unmarked gene mutations, which hinge on using a counterselective marker. Previously, the galk -based allelic exchange method, while effective, faced an inherent limitation - the need for a modified host. This study aims to surmount this limitation by substituting galK with sacB for gene modification in F. nucleatum . Our application of the sacB -based methodology successfully yielded a tonB in-frame deletion mutant and a luciferase gene knockin at the precise chromosomal location in the wild-type background. The new method augments the existing toolkit for F. nucleatum research and has far-reaching implications due to the easy accessibility to the counterselection compound sucrose. We anticipate its broader adoption in further exploration, thereby reinforcing its critical role in propelling our understanding of F. nucleatum .
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Luo VC, Peczuh MW. Location, Location, Location: Establishing Design Principles for New Antibacterials from Ferric Siderophore Transport Systems. Molecules 2024; 29:3889. [PMID: 39202968 PMCID: PMC11357680 DOI: 10.3390/molecules29163889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Revised: 08/09/2024] [Accepted: 08/12/2024] [Indexed: 09/03/2024] Open
Abstract
This review strives to assemble a set of molecular design principles that enables the delivery of antibiotic warheads to Gram-negative bacterial targets (ESKAPE pathogens) using iron-chelating siderophores, known as the Trojan Horse strategy for antibiotic development. Principles are derived along two main lines. First, archetypical siderophores and their conjugates are used as case studies for native iron transport. They enable the consideration of the correspondence of iron transport and antibacterial target location. The second line of study charts the rationale behind the clinical antibiotic cefiderocol. It illustrates the potential versatility for the design of new Trojan Horse-based antibiotics. Themes such as matching the warhead to a location where the siderophore delivers its cargo (i.e., periplasm vs. cytoplasm), whether or not a cleavable linker is required, and the relevance of cheaters to the effectiveness and selectivity of new conjugates will be explored. The effort to articulate rules has identified gaps in the current understanding of iron transport pathways and suggests directions for new investigations.
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Affiliation(s)
| | - Mark W. Peczuh
- Department of Chemistry, University of Connecticut, 55 N. Eagleville Road, U3060, Storrs, CT 06269, USA;
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Kalenborn S, Zühlke D, Reintjes G, Riedel K, Amann RI, Harder J. Genes for laminarin degradation are dispersed in the genomes of particle-associated Maribacter species. Front Microbiol 2024; 15:1393588. [PMID: 39188312 PMCID: PMC11345257 DOI: 10.3389/fmicb.2024.1393588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 07/17/2024] [Indexed: 08/28/2024] Open
Abstract
Laminarin is a cytosolic storage polysaccharide of phytoplankton and macroalgae and accounts for over 10% of the world's annually fixed carbon dioxide. Algal disruption, for example, by viral lysis releases laminarin. The soluble sugar is rapidly utilized by free-living planktonic bacteria, in which sugar transporters and the degrading enzymes are frequently encoded in polysaccharide utilization loci. The annotation of flavobacterial genomes failed to identify canonical laminarin utilization loci in several particle-associated bacteria, in particular in strains of Maribacter. In this study, we report in vivo utilization of laminarin by Maribacter forsetii accompanied by additional cell growth and proliferation. Laminarin utilization coincided with the induction of an extracellular endo-laminarinase, SusC/D outer membrane oligosaccharide transporters, and a periplasmic glycosyl hydrolase family 3 protein. An ABC transport system and sugar kinases were expressed. Endo-laminarinase activity was also observed in Maribacter sp. MAR_2009_72, Maribacter sp. Hel_I_7, and Maribacter dokdonensis MAR_2009_60. Maribacter dokdonensis MAR_2009_71 lacked the large endo-laminarinase gene in the genome and had no endo-laminarinase activity. In all genomes, genes of induced proteins were scattered across the genome rather than clustered in a laminarin utilization locus. These observations revealed that the Maribacter strains investigated in this study participate in laminarin utilization, but in contrast to many free-living bacteria, there is no co-localization of genes encoding the enzymatic machinery for laminarin utilization.
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Affiliation(s)
- Saskia Kalenborn
- Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Daniela Zühlke
- Department for Microbial Physiology and Molecular Biology, University of Greifswald, Greifswald, Germany
| | - Greta Reintjes
- Microbial Carbohydrate Interaction Group, Department of Biology and Chemistry, University of Bremen, Bremen, Germany
| | - Katharina Riedel
- Department for Microbial Physiology and Molecular Biology, University of Greifswald, Greifswald, Germany
| | - Rudolf I. Amann
- Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Jens Harder
- Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, Bremen, Germany
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Knejski PP, Erramilli SK, Kossiakoff AA. Chaperone-assisted cryo-EM structure of P. aeruginosa PhuR reveals molecular basis for heme binding. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.01.551527. [PMID: 37577460 PMCID: PMC10418163 DOI: 10.1101/2023.08.01.551527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Pathogenic bacteria, such as Pseudomonas aeruginosa, depend on scavenging heme for the acquisition of iron, an essential nutrient. The TonB-dependent transporter (TBDT) PhuR is the major heme uptake protein in P. aeruginosa clinical isolates. However, a comprehensive understanding of heme recognition and TBDT transport mechanisms, especially PhuR, remains limited. In this study, we employed single-particle cryogenic electron microscopy (cryo-EM) and a phage display-generated synthetic antibody (sAB) as a fiducial marker to enable the determination of a high-resolution (2.5 Å) structure of PhuR with a bound heme. Notably, the structure reveals iron coordination by Y529 on a conserved extracellular loop, shedding light on the role of tyrosine in heme binding. Biochemical assays and negative-stain EM demonstrated that the sAB specifically targets the heme-bound state of PhuR. These findings provide insights into PhuR's heme binding and offer a template for developing conformation-specific sABs against outer membrane proteins (OMPs) for structure-function investigations.
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Affiliation(s)
- Paweł P. Knejski
- Deparment of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
- Laboratory of Medical Biology, Faculty of Biotechnology, University of Wrocław, Wrocław 50-383, Poland
- Present address: Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zürich, Zürich 8093, Switzerland
| | - Satchal K. Erramilli
- Deparment of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
- Present address: Meso Scale Diagnostics, LLC, Rockville, Maryland 20850, USA
| | - Anthony A. Kossiakoff
- Deparment of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA
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Ryngajłło M, Cielecka I, Daroch M. Complete genome sequence and transcriptome response to vitamin C supplementation of Novacetimonas hansenii SI1 - producer of highly-stretchable cellulose. N Biotechnol 2024; 81:57-68. [PMID: 38531507 DOI: 10.1016/j.nbt.2024.03.004] [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: 10/24/2023] [Revised: 02/28/2024] [Accepted: 03/23/2024] [Indexed: 03/28/2024]
Abstract
Novacetimonas hansenii SI1, previously known as Komagataeibacter hansenii, produces bacterial nanocellulose (BNC) with unique ability to stretch. The addition of vitamin C in the culture medium increases the porosity of the membranes and their stretchability making them highly moldable. To better understand the genetic background of this strain, we obtained its complete genome sequence using a hybrid sequencing and assembly strategy. We described the functional regions in the genome which are important for the synthesis of BNC and acetan-like II polymer. We next investigated the effect of 1% vitamin C supplementation on the global gene expression profile using RNA sequencing. Our transcriptomic readouts imply that vitamin C functions mainly as a reducing agent. We found that the changes in cellular redox status are balanced by strong repression of the sulfur assimilation pathway. Moreover, in the reduced conditions, glucose oxidation is decreased and alternative pathways for energy generation, such as acetate accumulation, are activated. The presence of vitamin C negatively influences acetan-like II polymer biosynthesis, which may explain the lowered yield and changed mechanical properties of BNC. The results of this study enrich the functional characteristics of the genomes of the efficient producers of the N. hansenii species. Improved understanding of the adaptation to the presence of vitamin C at the molecular level has important guiding significance for influencing the biosynthesis of BNC and its morphology.
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Affiliation(s)
- Małgorzata Ryngajłło
- Institute of Molecular and Industrial Biotechnology, Lodz University of Technology, B. Stefanowskiego 2/22, Lodz 90-537, Poland.
| | - Izabela Cielecka
- Institute of Molecular and Industrial Biotechnology, Lodz University of Technology, B. Stefanowskiego 2/22, Lodz 90-537, Poland
| | - Maurycy Daroch
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, China
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9
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Hiralal A, Geelhoed JS, Neukirchen S, Meysman FJR. Comparative genomic analysis of nickel homeostasis in cable bacteria. BMC Genomics 2024; 25:692. [PMID: 39009997 PMCID: PMC11247825 DOI: 10.1186/s12864-024-10594-7] [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: 03/27/2024] [Accepted: 07/03/2024] [Indexed: 07/17/2024] Open
Abstract
BACKGROUND Cable bacteria are filamentous members of the Desulfobulbaceae family that are capable of performing centimetre‑scale electron transport in marine and freshwater sediments. This long‑distance electron transport is mediated by a network of parallel conductive fibres embedded in the cell envelope. This fibre network efficiently transports electrical currents along the entire length of the centimetre‑long filament. Recent analyses show that these fibres consist of metalloproteins that harbour a novel nickel‑containing cofactor, which indicates that cable bacteria have evolved a unique form of biological electron transport. This nickel‑dependent conduction mechanism suggests that cable bacteria are strongly dependent on nickel as a biosynthetic resource. Here, we performed a comprehensive comparative genomic analysis of the genes linked to nickel homeostasis. We compared the genome‑encoded adaptation to nickel of cable bacteria to related members of the Desulfobulbaceae family and other members of the Desulfobulbales order. RESULTS Presently, four closed genomes are available for the monophyletic cable bacteria clade that consists of the genera Candidatus Electrothrix and Candidatus Electronema. To increase the phylogenomic coverage, we additionally generated two closed genomes of cable bacteria: Candidatus Electrothrix gigas strain HY10‑6 and Candidatus Electrothrix antwerpensis strain GW3‑4, which are the first closed genomes of their respective species. Nickel homeostasis genes were identified in a database of 38 cable bacteria genomes (including 6 closed genomes). Gene prevalence was compared to 19 genomes of related strains, residing within the Desulfobulbales order but outside of the cable bacteria clade, revealing several genome‑encoded adaptations to nickel homeostasis in cable bacteria. Phylogenetic analysis indicates that nickel importers, nickel‑binding enzymes and nickel chaperones of cable bacteria are affiliated to organisms outside the Desulfobulbaceae family, with several proteins showing affiliation to organisms outside of the Desulfobacterota phylum. Conspicuously, cable bacteria encode a unique periplasmic nickel export protein RcnA, which possesses a putative cytoplasmic histidine‑rich loop that has been largely expanded compared to RcnA homologs in other organisms. CONCLUSION Cable bacteria genomes show a clear genetic adaptation for nickel utilization when compared to closely related genera. This fully aligns with the nickel‑dependent conduction mechanism that is uniquely found in cable bacteria.
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Affiliation(s)
- Anwar Hiralal
- Geobiology Research Group, University of Antwerp, Antwerp, Belgium
| | | | - Sinje Neukirchen
- Geobiology Research Group, University of Antwerp, Antwerp, Belgium
| | - Filip J R Meysman
- Geobiology Research Group, University of Antwerp, Antwerp, Belgium.
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.
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Ruiz-Fresneda MA, Lazúen-López G, Pérez-Muelas E, Peña-Martín J, Linares-Jiménez RE, Newman-Portela AM, Merroun ML. Identification of a multi-modal mechanism for Se(VI) reduction and Se(0) allotropic transition by Stenotrophomonas bentonitica. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024:10.1007/s11356-024-34256-z. [PMID: 38995337 DOI: 10.1007/s11356-024-34256-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 07/02/2024] [Indexed: 07/13/2024]
Abstract
Microorganisms can play a key role in selenium (Se) bioremediation and the fabrication of Se-based nanomaterials by reducing toxic forms (Se(VI) and Se(IV)) into Se(0). In recent years, omics have become a useful tool in understanding the metabolic pathways involved in the reduction process. This paper aims to elucidate the specific molecular mechanisms involved in Se(VI) reduction by the bacterium Stenotrophomonas bentonitica. Both cytoplasmic and membrane fractions were able to reduce Se(VI) to Se(0) nanoparticles (NPs) with different morphologies (nanospheres and nanorods) and allotropes (amorphous, monoclinic, and trigonal). Proteomic analyses indicated an adaptive response against Se(VI) through the alteration of several metabolic pathways including those related to energy acquisition, synthesis of proteins and nucleic acids, and transport systems. Whilst the thioredoxin system and the Painter reactions were identified to play a crucial role in Se reduction, flagellin may also be involved in the allotropic transformation of Se. These findings suggest a multi-modal reduction mechanism is involved, providing new insights for developing novel strategies in bioremediation and nanoparticle synthesis for the recovery of critical materials within the concept of circular economy.
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Affiliation(s)
| | - Guillermo Lazúen-López
- Department of Microbiology, University of Granada, Campus Fuentenueva, 18071, Granada, Spain
| | - Eduardo Pérez-Muelas
- Department of Microbiology, University of Granada, Campus Fuentenueva, 18071, Granada, Spain
| | - Jesús Peña-Martín
- Department of Human Anatomy and Embryology, Faculty of Medicine, University of Granada, 18016, Granada, Spain
- Centre for Biomedical Research (CIBM), Biopathology and Regenerative Medicine Institute (IBIMER), University of Granada, 18100, Granada, Spain
| | - Raúl Eduardo Linares-Jiménez
- Department of Microbiology, University of Granada, Campus Fuentenueva, 18071, Granada, Spain
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | | | - Mohamed Larbi Merroun
- Department of Microbiology, University of Granada, Campus Fuentenueva, 18071, Granada, Spain
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Shin HE, Pan C, Curran DM, Bateman TJ, Chong DHY, Ng D, Shah M, Moraes TF. Prevalence of Slam-dependent hemophilins in Gram-negative bacteria. J Bacteriol 2024; 206:e0002724. [PMID: 38814789 PMCID: PMC11332172 DOI: 10.1128/jb.00027-24] [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: 01/25/2024] [Accepted: 05/08/2024] [Indexed: 06/01/2024] Open
Abstract
Iron acquisition systems are crucial for pathogen growth and survival in iron-limiting host environments. To overcome nutritional immunity, bacterial pathogens evolved to use diverse mechanisms to acquire iron. Here, we examine a heme acquisition system that utilizes hemophores called hemophilins which are also referred to as HphAs in several Gram-negative bacteria. In this study, we report three new HphA structures from Stenotrophomonas maltophilia, Vibrio harveyi, and Haemophilus parainfluenzae. Structural determination of HphAs revealed an N-terminal clamp-like domain that binds heme and a C-terminal eight-stranded β-barrel domain that shares the same architecture as the Slam-dependent Neisserial surface lipoproteins. The genetic organization of HphAs consists of genes encoding a Slam homolog and a TonB-dependent receptor (TBDR). We investigated the Slam-HphA system in the native organism or the reconstituted system in Escherichia coli cells and found that the efficient secretion of HphA depends on Slam. The TBDR also played an important role in heme uptake and conferred specificity for its cognate HphA. Furthermore, bioinformatic analysis of HphA homologs revealed that HphAs are conserved in the alpha, beta, and gammaproteobacteria. Together, these results show that the Slam-dependent HphA-type hemophores are prevalent in Gram-negative bacteria and further expand the role of Slams in transporting soluble proteins. IMPORTANCE This paper describes the structure and function of a family of Slam (Type IX secretion System) secreted hemophores that bacteria use to uptake heme (iron) while establishing an infection. Using structure-based bioinformatics analysis to define the diversity and prevalence of this heme acquisition pathway, we discovered that a large portion of gammaproteobacterial harbors this system. As organisms, including Acinetobacter baumannii, utilize this system to facilitate survival during host invasion, the identification of this heme acquisition system in bacteria species is valuable information and may represent a target for antimicrobials.
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Affiliation(s)
- Hyejin Esther Shin
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Chuxi Pan
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - David M. Curran
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Thomas J. Bateman
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | | | - Dixon Ng
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Megha Shah
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Trevor F. Moraes
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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12
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Vikraman D, Majumdar BB, Sk S, Weichbrodt C, Fertig N, Winterhalter M, Mondal J, Mahendran KR. Conformational flexibility driving charge-selective substrate translocation across a bacterial transporter. Chem Sci 2024; 15:9333-9344. [PMID: 38903220 PMCID: PMC11186346 DOI: 10.1039/d4sc00345d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 05/11/2024] [Indexed: 06/22/2024] Open
Abstract
Bacterial membrane porins facilitate the translocation of small molecules while restricting large molecules, and this mechanism remains elusive at the molecular level. Here, we investigate the selective uptake of large cyclic sugars across an unusual passive membrane transporter, CymA, comprising a charged zone and a constricting N terminus segment. Using a combination of electrical recordings, protein mutagenesis and molecular dynamics simulations, we establish substrate translocation across CymA governed by the electrostatic pore properties and conformational dynamics of the constriction segment. Notably, we show that the variation in pH of the environment resulted in reversible modulation of the substrate binding site in the pore, thereby regulating charge-selective transport of cationic, anionic and neutral cyclic sugars. The quantitative kinetics of cyclic sugar translocation across CymA obtained in electrical recordings at different pHs are comparable with molecular dynamics simulations that revealed the transport pathway, energetics and favorable affinity sites in the pore for substrate binding. We further define the molecular basis of cyclic sugar translocation and establish that the constriction segment is flexible and can reside inside or outside the pore, regulating substrate translocation distinct from the ligand-gated transport mechanism. Our study provides novel insights into energy-independent large molecular membrane transport for targeted drug design strategies.
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Affiliation(s)
- Devika Vikraman
- Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology Thiruvananthapuram 695014 India
- Manipal Academy of Higher Education Manipal Karnataka-576104 India
| | | | - Sharavanakkumar Sk
- Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology Thiruvananthapuram 695014 India
| | | | | | - Mathias Winterhalter
- School of Science, Constructor University Campus Ring 1 28759 Bremen Germany
- Center for Hybrid Nanostructures (CHyN), Universität Hamburg Luruper Chaussee 149 Hamburg 22761 Germany
| | - Jagannath Mondal
- Tata Institute of Fundamental Research Hyderabad Telangana-500046 India
| | - Kozhinjampara R Mahendran
- Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology Thiruvananthapuram 695014 India
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13
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Asefi S, Nouri H, Pourmohammadi G, Moghimi H. Comprehensive network of stress-induced responses in Zymomonas mobilis during bioethanol production: from physiological and molecular responses to the effects of system metabolic engineering. Microb Cell Fact 2024; 23:180. [PMID: 38890644 PMCID: PMC11186258 DOI: 10.1186/s12934-024-02459-1] [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: 10/05/2023] [Accepted: 06/13/2024] [Indexed: 06/20/2024] Open
Abstract
Nowadays, biofuels, especially bioethanol, are becoming increasingly popular as an alternative to fossil fuels. Zymomonas mobilis is a desirable species for bioethanol production due to its unique characteristics, such as low biomass production and high-rate glucose metabolism. However, several factors can interfere with the fermentation process and hinder microbial activity, including lignocellulosic hydrolysate inhibitors, high temperatures, an osmotic environment, and high ethanol concentration. Overcoming these limitations is critical for effective bioethanol production. In this review, the stress response mechanisms of Z. mobilis are discussed in comparison to other ethanol-producing microbes. The mechanism of stress response is divided into physiological (changes in growth, metabolism, intracellular components, and cell membrane structures) and molecular (up and down-regulation of specific genes and elements of the regulatory system and their role in expression of specific proteins and control of metabolic fluxes) changes. Systemic metabolic engineering approaches, such as gene manipulation, overexpression, and silencing, are successful methods for building new metabolic pathways. Therefore, this review discusses systems metabolic engineering in conjunction with systems biology and synthetic biology as an important method for developing new strains with an effective response mechanism to fermentation stresses during bioethanol production. Overall, understanding the stress response mechanisms of Z. mobilis can lead to more efficient and effective bioethanol production.
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Affiliation(s)
- Shaqayeq Asefi
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Hoda Nouri
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran.
| | - Golchehr Pourmohammadi
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Hamid Moghimi
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran.
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14
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You LX, Zhong HL, Chen SR, Sun YN, Wu GK, Zhao MX, Hu SS, Alwathnani H, Herzberg M, Qin SF, Rensing C. Biosynthesis of silver nanoparticles using Burkholderia contaminans ZCC and mechanistic analysis at the proteome level. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 278:116425. [PMID: 38723385 DOI: 10.1016/j.ecoenv.2024.116425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 03/31/2024] [Accepted: 04/30/2024] [Indexed: 05/26/2024]
Abstract
The biogenic synthesis of silver nanoparticles (AgNPs) by microorganisms has been a subject of increasing attention. Despite extensive studies on this biosynthetic pathway, the mechanisms underlying the involvement of proteins and enzymes in AgNPs production have not been fully explored. Herein, we reported that Burkholderia contaminans ZCC was able to reduce Ag+ to AgNPs with a diameter of (10±5) nm inside the cell. Exposure of B. contaminans ZCC to Ag+ ions led to significant changes in the functional groups of cellular proteins, with approximately 5.72% of the (C-OH) bonds being converted to (C-C/C-H) (3.61%) and CO (2.11%) bonds, and 4.52% of the CO (carbonyl) bonds being converted to (C-OH) bonds. Furthermore, the presence of Ag+ and AgNPs induced the ability of extracellular electron transfer for ZCC cells via specific membrane proteins, but this did not occur in the absence of Ag+ ions. Proteomic analysis of the proteins and enzymes involved in heavy metal efflux systems, protein secretion system, oxidative phosphorylation, intracellular electron transfer chain, and glutathione metabolism suggests that glutathione S-transferase and ubiquinol-cytochrome c reductase iron-sulfur subunit play importance roles in the biosynthesis of AgNPs. These findings contribute to a deeper understanding of the functions exerted by glutathione S-transferase and ferredoxin-thioredoxin reductase iron-sulfur subunits in the biogenesis of AgNPs, thereby hold immense potential for optimizing biotechnological techniques aimed at enhancing the yield and purity of biosynthetic AgNPs.
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Affiliation(s)
- Le-Xing You
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China.
| | - Hong-Lin Zhong
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China; Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China
| | - Si-Ru Chen
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China
| | - Yi-Nan Sun
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China
| | - Gao-Kai Wu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China
| | - Meng-Xin Zhao
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China
| | - Shan-Shan Hu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004, PR China
| | - Hend Alwathnani
- Department of Botany and Microbiology, King Saud University, Riyadh, Saudi Arabia
| | - Martin Herzberg
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Su-Fang Qin
- College of Pharmacy, Jinhua Polytechnic, Jinhua 321007, PR China.
| | - Christopher Rensing
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
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15
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Younker IT, Molnar N, Scorza K, Weed R, Light SH, Pfister CA. Bacteria on the foundational kelp in kelp forest ecosystems: Insights from culturing, whole genome sequencing and metabolic assays. ENVIRONMENTAL MICROBIOLOGY REPORTS 2024; 16:e13270. [PMID: 38778582 PMCID: PMC11112141 DOI: 10.1111/1758-2229.13270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 04/06/2024] [Indexed: 05/25/2024]
Abstract
In coastal marine ecosystems, kelp forests serve as a vital habitat for numerous species and significantly influence local nutrient cycles. Bull kelp, or Nereocystis luetkeana, is a foundational species in the iconic kelp forests of the northeast Pacific Ocean and harbours a complex microbial community with potential implications for kelp health. Here, we report the isolation and functional characterisation of 16 Nereocystis-associated bacterial species, comprising 13 Gammaproteobacteria, 2 Flavobacteriia and 1 Actinomycetia. Genome analyses of these isolates highlight metabolisms potentially beneficial to the host, such as B vitamin synthesis and nitrogen retention. Assays revealed that kelp-associated bacteria thrive on amino acids found in high concentrations in the ocean and in the kelp (glutamine and asparagine), generating ammonium that may facilitate host nitrogen acquisition. Multiple isolates have genes indicative of interactions with key elemental cycles in the ocean, including carbon, nitrogen and sulphur. We thus report a collection of kelp-associated microbial isolates that provide functional insight for the future study of kelp-microbe interactions.
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Affiliation(s)
- Isaac T. Younker
- Committee on MicrobiologyThe University of ChicagoChicagoIllinoisUSA
| | - Nichos Molnar
- The CollegeThe University of ChicagoChicagoIllinoisUSA
| | - Kaylie Scorza
- The CollegeThe University of ChicagoChicagoIllinoisUSA
| | - Roo Weed
- The Graduate Program in Biophysical SciencesThe University of ChicagoChicagoIllinoisUSA
| | - Samuel H. Light
- Department of MicrobiologyThe University of ChicagoChicagoIllinoisUSA
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16
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Cherrak Y, Salazar MA, Yilmaz K, Kreuzer M, Hardt WD. Commensal E. coli limits Salmonella gut invasion during inflammation by producing toxin-bound siderophores in a tonB-dependent manner. PLoS Biol 2024; 22:e3002616. [PMID: 38865418 PMCID: PMC11168627 DOI: 10.1371/journal.pbio.3002616] [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: 12/13/2023] [Accepted: 04/05/2024] [Indexed: 06/14/2024] Open
Abstract
The gastrointestinal tract is densely colonized by a polymicrobial community known as the microbiota which serves as primary line of defence against pathogen invasion. The microbiota can limit gut-luminal pathogen growth at different stages of infection. This can be traced to specific commensal strains exhibiting direct or indirect protective functions. Although these mechanisms hold the potential to develop new approaches to combat enteric pathogens, they remain far from being completely described. In this study, we investigated how a mouse commensal Escherichia coli can outcompete Salmonella enterica serovar Typhimurium (S. Tm). Using a salmonellosis mouse model, we found that the commensal E. coli 8178 strain relies on a trojan horse trap strategy to limit S. Tm expansion in the inflamed gut. Combining mutants and reporter tools, we demonstrated that inflammation triggers the expression of the E. coli 8178 antimicrobial microcin H47 toxin which, when fused to salmochelin siderophores, can specifically alter S. Tm growth. This protective function was compromised upon disruption of the E. coli 8178 tonB-dependent catecholate siderophore uptake system, highlighting a previously unappreciated crosstalk between iron intake and microcin H47 activity. By identifying the genetic determinants mediating S. Tm competition, our work not only provides a better mechanistic understanding of the protective function displayed by members of the gut microbiota but also further expands the general contribution of microcins in bacterial antagonistic relationships. Ultimately, such insights can open new avenues for developing microbiota-based approaches to better control intestinal infections.
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Affiliation(s)
- Yassine Cherrak
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Miguel Angel Salazar
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Koray Yilmaz
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Markus Kreuzer
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Wolf-Dietrich Hardt
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
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17
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Kirsch JM, Hryckowian AJ, Duerkop BA. A metagenomics pipeline reveals insertion sequence-driven evolution of the microbiota. Cell Host Microbe 2024; 32:739-754.e4. [PMID: 38565143 PMCID: PMC11081829 DOI: 10.1016/j.chom.2024.03.005] [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: 10/16/2023] [Revised: 02/06/2024] [Accepted: 03/08/2024] [Indexed: 04/04/2024]
Abstract
Insertion sequence (IS) elements are mobile genetic elements in bacterial genomes that support adaptation. We developed a database of IS elements coupled to a computational pipeline that identifies IS element insertions in the microbiota. We discovered that diverse IS elements insert into the genomes of intestinal bacteria regardless of human host lifestyle. These insertions target bacterial accessory genes that aid in their adaptation to unique environmental conditions. Using IS expansion in Bacteroides, we show that IS activity leads to the insertion of "hot spots" in accessory genes. We show that IS insertions are stable and can be transferred between humans. Extreme environmental perturbations force IS elements to fall out of the microbiota, and many fail to rebound following homeostasis. Our work shows that IS elements drive bacterial genome diversification within the microbiota and establishes a framework for understanding how strain-level variation within the microbiota impacts human health.
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Affiliation(s)
- Joshua M Kirsch
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045, USA
| | - Andrew J Hryckowian
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA; Department of Medical Microbiology & Immunology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Breck A Duerkop
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045, USA.
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18
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Carson DV, Juarez RJ, Do T, Yang Z, James Link A. Antimicrobial Lasso Peptide Cloacaenodin Utilizes a Unique TonB-Dependent Transporter to Access Susceptible Bacteria. ACS Chem Biol 2024; 19:981-991. [PMID: 38527226 PMCID: PMC11031277 DOI: 10.1021/acschembio.4c00009] [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] [Indexed: 03/27/2024]
Abstract
The development of new antimicrobial agents effective against Gram-negative bacteria remains a major challenge in drug discovery. The lasso peptide cloacaenodin has potent antimicrobial activity against multiple strains in the Enterobacter genus, one of the ESKAPE pathogens. Here, we show that cloacaenodin uses a previously uncharacterized TonB-dependent transporter, which we name CloU, to cross the outer membrane (OM) of susceptible bacteria. Inner membrane transport is mediated by the protein SbmA. CloU is distinct from the known OM transporters (FhuA and PupB) utilized by other antimicrobial lasso peptides and thus offers important insight into the spectrum of activity of cloacaenodin. Using knowledge of the transport pathway to predict other cloacaenodin-susceptible strains, we demonstrate the activity of cloacaenodin against clinical isolates of Enterobacter and of a Kluyvera strain. Further, we use molecular dynamics simulations and mutagenesis of CloU to explain the variation in cloacaenodin susceptibility observed across different strains of Enterobacter. This work expands the currently limited understanding of lasso peptide uptake and advances the potential of cloacaenodin as an antibiotic.
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Affiliation(s)
- Drew V. Carson
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Reecan J. Juarez
- Chemical and Physical Biology Program, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Truc Do
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Zhongyue Yang
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
- Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37235, United States
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37235, United States
- Data Science Institute, Vanderbilt University, Nashville, Tennessee 37235, United States
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - A. James Link
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, United States
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19
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Méndez-Sotelo BJ, Delgado-Beltrán M, Hernández-Durán M, Colín-Castro CA, Esquivel-Bautista J, Ortega-Oliva SA, Ortiz-Álvarez J, García-Contreras R, Franco-Cendejas R, Lopez Jacome LE. In vitro activity of ceftazidime/avibactam, cefiderocol, meropenem/vaborbactam and imipenem/relebactam against clinical strains of the Stenotrophomonas maltophilia complex. PLoS One 2024; 19:e0298577. [PMID: 38635685 PMCID: PMC11025899 DOI: 10.1371/journal.pone.0298577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 01/28/2024] [Indexed: 04/20/2024] Open
Abstract
BACKGROUND Infections caused by Stenotrophomonas maltophilia and related species are increasing worldwide. Unfortunately, treatment options are limited, whereas the antimicrobial resistance is increasing. METHODS We included clinical isolates identified as S. maltophilia by VITEK 2 Compact. Ceftazidime/avibactam, meropenem/vaborbactam, imipenem/relebactam, cefiderocol, quinolones, and tetracycline family members were evaluated by broth microdilution method and compared with first-line treatment drugs. Minimum inhibitory concentrations (MICs) were reported for all antibiotics. We sequenced the Whole Genome of cefiderocol resistant strains (CRSs) and annotated their genes associated with cefiderocol resistance (GACR). Presumptive phylogenetic identification employing the 16S marker was performed. RESULTS One hundred and one clinical strains were evaluated, sulfamethoxazole and trimethoprim, levofloxacin and minocycline showed susceptibilities of 99.01%, 95.04% and 100% respectively. Ceftazidime was the antibiotic with the highest percentage of resistance in all samples (77.22%). Five strains were resistant to cefiderocol exhibiting MIC values ≥ 2 μg/mL (4.95%). The β-lactamase inhibitors meropenem/vaborbactam and imipenem/relebactam, failed to inhibit S. maltophilia, preserving both MIC50 and MIC90 ≥64 μg/mL. Ceftazidime/avibactam restored the activity of ceftazidime decreasing the MIC range. Tigecycline had the lowest MIC range, MIC50 and MIC90. Phylogeny based on 16S rRNA allowed to identify to cefiderocol resistant strains as putative species clustered into Stenotrophomonas maltophilia complex (Smc). In these strains, we detected GARCs such as Mutiple Drug Resistance (MDR) efflux pumps, L1-type β-lactamases, iron transporters and type-1 fimbriae. CONCLUSION Antimicrobial resistance to first-line treatment is low. The in vitro activity of new β-lactamase inhibitors against S. maltophilia is poor, but avibactam may be a potential option. Cefiderocol could be considered as a potential new option for multidrug resistant infections. Tetracyclines had the best in vitro activity of all antibiotics evaluated.
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Affiliation(s)
- Braulio Josué Méndez-Sotelo
- Infectious Diseases Division, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Mexico City, Mexico
| | | | - Melissa Hernández-Durán
- Clinical Microbiology Laboratory, Infectious Diseases Division, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Mexico City, Mexico
| | - Claudia Adriana Colín-Castro
- Clinical Microbiology Laboratory, Infectious Diseases Division, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Mexico City, Mexico
| | - José Esquivel-Bautista
- Centro Nacional de Referencia de Inocuidad y Bioseguridad Agroalimentaria, Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria (SENASICA), Tecámac, Mexico State, Mexico
| | - Sandra Angélica Ortega-Oliva
- Centro Nacional de Referencia de Inocuidad y Bioseguridad Agroalimentaria, Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria (SENASICA), Tecámac, Mexico State, Mexico
| | - Jossue Ortiz-Álvarez
- Programa “Investigadoras e Investigadores por México”, Consejo Nacional de Humanidades, Ciencias y Tecnologías (CONAHCYT), Mexico City, Mexico
| | - Rodolfo García-Contreras
- Medicine Faculty, Bacteriology Laboratory, Microbiology and Parasitology Department, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Rafael Franco-Cendejas
- Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Biomedical Research Subdirection, Mexico City, Mexico
| | - Luis Esau Lopez Jacome
- Clinical Microbiology Laboratory, Infectious Diseases Division, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Mexico City, Mexico
- Chemistry Faculty, Biology Department, Universidad Nacional Autónoma de México, Mexico City, Mexico
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20
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Kalenborn S, Zühlke D, Riedel K, Amann RI, Harder J. Proteomic insight into arabinogalactan utilization by particle-associated Maribacter sp. MAR_2009_72. FEMS Microbiol Ecol 2024; 100:fiae045. [PMID: 38569650 PMCID: PMC11036162 DOI: 10.1093/femsec/fiae045] [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: 02/05/2024] [Revised: 03/13/2024] [Accepted: 04/02/2024] [Indexed: 04/05/2024] Open
Abstract
Arabinose and galactose are major, rapidly metabolized components of marine particulate and dissolved organic matter. In this study, we observed for the first time large microbiomes for the degradation of arabinogalactan and report a detailed investigation of arabinogalactan utilization by the flavobacterium Maribacter sp. MAR_2009_72. Cellular extracts hydrolysed arabinogalactan in vitro. Comparative proteomic analyses of cells grown on arabinogalactan, arabinose, galactose, and glucose revealed the expression of specific proteins in the presence of arabinogalactan, mainly glycoside hydrolases (GH). Extracellular glycan hydrolysis involved five alpha-l-arabinofuranosidases affiliating with glycoside hydrolase families 43 and 51, four unsaturated rhamnogalacturonylhydrolases (GH105) and a protein with a glycoside hydrolase family-like domain. We detected expression of three induced TonB-dependent SusC/D transporter systems, one SusC, and nine glycoside hydrolases with a predicted periplasmatic location. These are affiliated with the families GH3, GH10, GH29, GH31, GH67, GH78, and GH115. The genes are located outside of and within canonical polysaccharide utilization loci classified as specific for arabinogalactan, for galactose-containing glycans, and for arabinose-containing glycans. The breadth of enzymatic functions expressed in Maribacter sp. MAR_2009_72 as response to arabinogalactan from the terrestrial plant larch suggests that Flavobacteriia are main catalysts of the rapid turnover of arabinogalactans in the marine environment.
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Affiliation(s)
- Saskia Kalenborn
- Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, Celsiusstr. 1, D-28359 Bremen, Germany
| | - Daniela Zühlke
- Department for Microbial Physiology and Molecular Biology, University of Greifswald, Felix-Hausdorff-Str. 8, D-17489 Greifswald, Germany
| | - Katharina Riedel
- Department for Microbial Physiology and Molecular Biology, University of Greifswald, Felix-Hausdorff-Str. 8, D-17489 Greifswald, Germany
| | - Rudolf I Amann
- Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, Celsiusstr. 1, D-28359 Bremen, Germany
| | - Jens Harder
- Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, Celsiusstr. 1, D-28359 Bremen, Germany
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21
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Li Y, Liu Q, Zhang DX, Zhang ZY, Xu A, Jiang YL, Chen ZC. Metal nutrition and transport in the process of symbiotic nitrogen fixation. PLANT COMMUNICATIONS 2024; 5:100829. [PMID: 38303509 PMCID: PMC11009365 DOI: 10.1016/j.xplc.2024.100829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/14/2024] [Accepted: 01/26/2024] [Indexed: 02/03/2024]
Abstract
Symbiotic nitrogen fixation (SNF) facilitated by the interaction between legumes and rhizobia is a well-documented and eco-friendly alternative to chemical nitrogen fertilizers. Host plants obtain fixed nitrogen from rhizobia by providing carbon and mineral nutrients. These mineral nutrients, which are mostly in the form of metal ions, are implicated in various stages of the SNF process. This review describes the functional roles played by metal ions in nodule formation and nitrogen fixation and specifically addresses their transport mechanisms and associated transporters within root nodules. Future research directions and potential strategies for enhancing SNF efficiency are also discussed.
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Affiliation(s)
- Yuan Li
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Qian Liu
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Dan-Xun Zhang
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhuo-Yan Zhang
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Ao Xu
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yuan-Long Jiang
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhi-Chang Chen
- Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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22
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Knejski PP, Erramilli SK, Kossiakoff AA. Chaperone-assisted cryo-EM structure of P. aeruginosa PhuR reveals molecular basis for heme binding. Structure 2024; 32:411-423.e6. [PMID: 38325368 PMCID: PMC10997469 DOI: 10.1016/j.str.2024.01.007] [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: 08/02/2023] [Revised: 12/14/2023] [Accepted: 01/11/2024] [Indexed: 02/09/2024]
Abstract
Pathogenic bacteria, such as Pseudomonas aeruginosa, depend on scavenging heme for the acquisition of iron, an essential nutrient. The TonB-dependent transporter (TBDT) PhuR is the major heme uptake protein in P. aeruginosa clinical isolates. However, a comprehensive understanding of heme recognition and TBDT transport mechanisms, especially PhuR, remains limited. In this study, we employed single-particle cryogenic electron microscopy (cryo-EM) and a phage display-generated synthetic antibody (sAB) as a fiducial marker to enable the determination of a high-resolution (2.5 Å) structure of PhuR with a bound heme. Notably, the structure reveals iron coordination by Y529 on a conserved extracellular loop, shedding light on the role of tyrosine in heme binding. Biochemical assays and negative-stain EM demonstrated that the sAB specifically targets the heme-bound state of PhuR. These findings provide insights into PhuR's heme binding and offer a template for developing conformation-specific sABs against outer membrane proteins (OMPs) for structure-function investigations.
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Affiliation(s)
- Paweł P Knejski
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Laboratory of Medical Biology, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Satchal K Erramilli
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA.
| | - Anthony A Kossiakoff
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, USA; Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637, USA.
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23
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Goult JD, Van DCL, Taylor YV, Inns PG, Kaminska R, Vesely M, Kleanthous C, Paci E. Structural constraints of pyocin S2 import through the ferripyoverdine receptor FpvAI. PNAS NEXUS 2024; 3:pgae124. [PMID: 38577260 PMCID: PMC10994204 DOI: 10.1093/pnasnexus/pgae124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 03/12/2024] [Indexed: 04/06/2024]
Abstract
TonB-dependent transporters (TBDTs) mediate energized transport of essential nutrients into gram-negative bacteria. TBDTs are increasingly being exploited for the delivery of antibiotics to drug-resistant bacteria. While much is known about ground state complexes of TBDTs, few details have emerged about the transport process itself. In this study, we exploit bacteriocin parasitization of a TBDT to probe the mechanics of transport. Previous work has shown that the N-terminal domain of Pseudomonas aeruginosa-specific bacteriocin pyocin S2 (PyoS2NTD) is imported through the pyoverdine receptor FpvAI. PyoS2NTD transport follows the opening of a proton-motive force-dependent pore through FpvAI and the delivery of its own TonB box that engages TonB. We use molecular models and simulations to formulate a complete translocation pathway for PyoS2NTD that we validate using protein engineering and cytotoxicity measurements. We show that following partial removal of the FpvAI plug domain which occludes the channel, the pyocin's N-terminus enters the channel by electrostatic steering and ratchets to the periplasm. Application of force, mimicking that exerted by TonB, leads to unraveling of PyoS2NTD as it squeezes through the channel. Remarkably, while some parts of PyoS2NTD must unfold, complete unfolding is not required for transport, a result we confirmed by disulfide bond engineering. Moreover, the section of the FpvAI plug that remains embedded in the channel appears to serve as a buttress against which PyoS2NTD is pushed to destabilize the domain. Our study reveals the limits of structural deformation that accompanies import through a TBDT and the role the TBDT itself plays in accommodating transport.
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Affiliation(s)
- Jonathan D Goult
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Daniel C L Van
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Yasmin V Taylor
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Patrick G Inns
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Renata Kaminska
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Martin Vesely
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Colin Kleanthous
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Emanuele Paci
- Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna 40127, Italy
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24
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Yang T, Zou Y, Ng HL, Kumar A, Newton SM, Klebba PE. Specificity and mechanism of TonB-dependent ferric catecholate uptake by Fiu. Front Microbiol 2024; 15:1355253. [PMID: 38601941 PMCID: PMC11005823 DOI: 10.3389/fmicb.2024.1355253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 01/23/2024] [Indexed: 04/12/2024] Open
Abstract
We studied the Escherichia coli outer membrane protein Fiu, a presumed transporter of monomeric ferric catecholates, by introducing Cys residues in its surface loops and modifying them with fluorescein maleimide (FM). Fiu-FM bound iron complexes of the tricatecholate siderophore enterobactin (FeEnt) and glucosylated enterobactin (FeGEnt), their dicatecholate degradation product Fe(DHBS)2 (FeEnt*), the monocatecholates dihydroxybenzoic acid (FeDHBA) and dihydroxybenzoyl serine (FeDHBS), and the siderophore antibiotics cefiderocol (FDC) and MB-1. Unlike high-affinity ligand-gated porins (LGPs), Fiu-FM had only micromolar affinity for iron complexes. Its apparent KD values for FeDHBS, FeDHBA, FeEnt*, FeEnt, FeGEnt, FeFDC, and FeMB-1 were 0.1, 0.7, 0.7, 1.0, 0.3, 0.4, and 4 μM, respectively. Despite its broad binding abilities, the transport repertoires of E. coli Fiu, as well as those of Cir and FepA, were less broad. Fiu only transported FeEnt*. Cir transported FeEnt* and FeDHBS (weakly); FepA transported FeEnt, FeEnt*, and FeDHBA. Both Cir and FepA bound FeGEnt, albeit with lower affinity. Related transporters of Acinetobacter baumannii (PiuA, PirA, BauA) had similarly moderate affinity and broad specificity for di- or monomeric ferric catecholates. Both microbiological and radioisotopic experiments showed Fiu's exclusive transport of FeEnt*, rather than ferric monocatecholate compounds. Molecular docking and molecular dynamics simulations predicted three binding sites for FeEnt*in the external vestibule of Fiu, and a fourth site deeper in its interior. Alanine scanning mutagenesis in the outermost sites (1a, 1b, and 2) decreased FeEnt* binding affinity as much as 20-fold and reduced or eliminated FeEnt* uptake. Finally, the molecular dynamics simulations suggested a pathway of FeEnt* movement through Fiu that may generally describe the process of metal transport by TonB-dependent receptors.
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Affiliation(s)
| | | | | | | | | | - Phillip E. Klebba
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States
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25
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Shaw DR, Tobon Gonzalez J, Bibiano Guadarrama C, Saikaly PE. Emerging biotechnological applications of anaerobic ammonium oxidation. Trends Biotechnol 2024:S0167-7799(24)00061-1. [PMID: 38519307 DOI: 10.1016/j.tibtech.2024.02.013] [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: 11/16/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/24/2024]
Abstract
Anaerobic ammonium oxidation (anammox) is an energy-efficient method for nitrogen removal that opens the possibility for energy-neutral wastewater treatment. Research on anammox over the past decade has primarily focused on its implementation in domestic wastewater treatment. However, emerging studies are now expanding its use to novel biotechnological applications and wastewater treatment processes. This review highlights recent advances in the anammox field that aim to overcome conventional bottlenecks, and explores novel and niche-specific applications of the anammox process. Despite the promising results and potential of these advances, challenges persist for their real-world implementation. This underscores the need for a transition from laboratory achievements to practical, scalable solutions for wastewater treatment which mark the next crucial phase in the evolution of anammox research.
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Affiliation(s)
- Dario Rangel Shaw
- Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
| | - Julian Tobon Gonzalez
- Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Carlos Bibiano Guadarrama
- Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Pascal E Saikaly
- Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia; Environmental Science and Engineering Program, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.
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26
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Xiong K, Deng L, Li Z, Gong H, Chen J, Huang M, Rao X, Cong Y. A TonB dependent transporter YncD of Salmonella enterica Serovar Typhi possesses vaccine potential. World J Microbiol Biotechnol 2024; 40:131. [PMID: 38470539 DOI: 10.1007/s11274-024-03937-9] [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: 12/12/2023] [Accepted: 02/22/2024] [Indexed: 03/14/2024]
Abstract
Multiple TonB dependent transporters (TBDTs) contribute to bacterial virulence due to the importance roles that their substrates play in bacterial growth, and possess vaccine potential. A putative TBDT, YncD, had been identified as one of in vivo induced antigens during human infection of typhoid fever, and is required for the pathogenicity of Salmonella enterica Serovar Typhi. The present study was aimed to determine the function and immunogenicity of YncD. Homologous recombination method was used to construct an yncD-deletion mutant and cirA-iroN-fepA-deletion mutant from the wild-type S. Typhi Ty2. The growth of mutants and the wild-type strain were assessed in iron-deficient medium, as well as in human macrophage cells. Recombinant YncD protein was expressed and purified using Ni-NTA affinity chromatography and anion exchange. A mouse model was then used to evaluate the immunogenicity and protection efficacy of the recombinant YncD. Antibody levels, serum bactericidal efficiency, passive immune protection, opsonophagocysis were assayed to analyse the immunoprotection mechanism of the recombinant YncD. Our results showed that YncD is associated with the iron-uptake of S. Typhi. The yncD-deletion mutant displayed impaired growth in iron-deficient medium, comparable to that the cirA-iroN-fepA-deletion mutant did. The mutation of yncD markedly decreased bacterial growth within human macrophage cells. Moreover, subcutaneous immunization of mice with recombinant YncD elicited high levels of specific anti-YncD IgG, IgG1 and IgG2a, which protected the immunized mice against the intraperitoneal challenge of S. Typhi, and decreased bacterial burdens in the livers and spleens of the infected mice. Passive immunization using the immunized sera also efficiently protected the mice from the challenge of S. Typhi. Moreover, the immunized sera enhanced in vitro bactericidal activity of complement, and opsonophagocytosis. Our results showed that YncD displays a role in the iron-uptake of S. Typhi and possesses immunogenicity.
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Affiliation(s)
- Kun Xiong
- Department of Clinical Laboratory, The First Dongguan Affiliated Hospital of Guangdong Medical University, Dongguan, Guangdong province, 523710, China
- Dongguan Key Laboratory of Pathogenesis and Experimental Diagnosis of Infectious Diseases, The First Dongguan Affiliated Hospital of Guangdong Medical University, Dongguan, Guangdong province, 523710, China
| | - Luxin Deng
- Department of Blood Transfusion, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan province, 646000, China
| | - Zhan Li
- Department of Blood Transfusion, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan province, 646000, China
| | - Haiyan Gong
- Department of Clinical Laboratory, The First Dongguan Affiliated Hospital of Guangdong Medical University, Dongguan, Guangdong province, 523710, China
- Dongguan Key Laboratory of Pathogenesis and Experimental Diagnosis of Infectious Diseases, The First Dongguan Affiliated Hospital of Guangdong Medical University, Dongguan, Guangdong province, 523710, China
| | - Jie Chen
- Department of Clinical Laboratory, The First Dongguan Affiliated Hospital of Guangdong Medical University, Dongguan, Guangdong province, 523710, China
- Dongguan Key Laboratory of Pathogenesis and Experimental Diagnosis of Infectious Diseases, The First Dongguan Affiliated Hospital of Guangdong Medical University, Dongguan, Guangdong province, 523710, China
| | - Mintao Huang
- Department of Clinical Laboratory, The First Dongguan Affiliated Hospital of Guangdong Medical University, Dongguan, Guangdong province, 523710, China
- Dongguan Key Laboratory of Pathogenesis and Experimental Diagnosis of Infectious Diseases, The First Dongguan Affiliated Hospital of Guangdong Medical University, Dongguan, Guangdong province, 523710, China
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Chongqiong, 400038, China.
| | - Yanguang Cong
- Department of Clinical Laboratory, The First Dongguan Affiliated Hospital of Guangdong Medical University, Dongguan, Guangdong province, 523710, China.
- Dongguan Key Laboratory of Pathogenesis and Experimental Diagnosis of Infectious Diseases, The First Dongguan Affiliated Hospital of Guangdong Medical University, Dongguan, Guangdong province, 523710, China.
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27
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Kirsch JM, Hryckowian AJ, Duerkop BA. A metagenomics pipeline reveals insertion sequence-driven evolution of the microbiota. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.06.561241. [PMID: 37873088 PMCID: PMC10592638 DOI: 10.1101/2023.10.06.561241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Insertion sequence (IS) elements are mobile genetic elements in bacterial genomes that support adaptation. We developed a database of IS elements coupled to a computational pipeline that identifies IS element insertions in the microbiota. We discovered that diverse IS elements insert into the genomes of intestinal bacteria regardless of human host lifestyle. These insertions target bacterial accessory genes that aid in their adaptation to unique environmental conditions. Using IS expansion in Bacteroides, we show that IS activity leads to insertion "hot spots" in accessory genes. We show that IS insertions are stable and can be transferred between humans. Extreme environmental perturbations force IS elements to fall out of the microbiota and many fail to rebound following homeostasis. Our work shows that IS elements drive bacterial genome diversification within the microbiota and establishes a framework for understanding how strain level variation within the microbiota impacts human health.
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Affiliation(s)
- Joshua M. Kirsch
- Department of Immunology and Microbiology, University of Colorado - Anschutz Medical Campus, School of Medicine, Aurora, Colorado, 80045, USA
| | - Andrew J. Hryckowian
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706, USA
- Department of Medical Microbiology & Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706, USA
| | - Breck A. Duerkop
- Department of Immunology and Microbiology, University of Colorado - Anschutz Medical Campus, School of Medicine, Aurora, Colorado, 80045, USA
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28
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Sarasa-Buisan C, Ochoa de Alda JAG, Velázquez-Suárez C, Rubio MÁ, Gómez-Baena G, Fillat MF, Luque I. An ancient bacterial zinc acquisition system identified from a cyanobacterial exoproteome. PLoS Biol 2024; 22:e3002546. [PMID: 38466754 PMCID: PMC10957091 DOI: 10.1371/journal.pbio.3002546] [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: 04/21/2023] [Revised: 03/21/2024] [Accepted: 02/12/2024] [Indexed: 03/13/2024] Open
Abstract
Bacteria have developed fine-tuned responses to cope with potential zinc limitation. The Zur protein is a key player in coordinating this response in most species. Comparative proteomics conducted on the cyanobacterium Anabaena highlighted the more abundant proteins in a zur mutant compared to the wild type. Experimental evidence showed that the exoprotein ZepA mediates zinc uptake. Genomic context of the zepA gene and protein structure prediction provided additional insights on the regulation and putative function of ZepA homologs. Phylogenetic analysis suggests that ZepA represents a primordial system for zinc acquisition that has been conserved for billions of years in a handful of species from distant bacterial lineages. Furthermore, these results show that Zur may have been one of the first regulators of the FUR family to evolve, consistent with the scarcity of zinc in the ecosystems of the Archean eon.
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Affiliation(s)
- Cristina Sarasa-Buisan
- Departamento de Bioquímica y Biología Molecular y Celular e Instituto de Biocomputación y Física de Sistemas Complejos (Bifi), Universidad de Zaragoza, Zaragoza, Spain
| | - Jesús A. G. Ochoa de Alda
- Didáctica de las Ciencias Experimentales y la Matemáticas, Universidad de Extremadura, Cáceres, Spain
| | | | - Miguel Ángel Rubio
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
| | - Guadalupe Gómez-Baena
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Córdoba, Spain
| | - María F. Fillat
- Departamento de Bioquímica y Biología Molecular y Celular e Instituto de Biocomputación y Física de Sistemas Complejos (Bifi), Universidad de Zaragoza, Zaragoza, Spain
| | - Ignacio Luque
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
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29
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Saichuer P, Khrisanapant P, Senapin S, Rattanarojpong T, Somsoros W, Khunrae P, Sangsuriya P. Evaluate the potential use of TonB-dependent receptor protein as a subunit vaccine against Aeromonas veronii infection in Nile tilapia (Oreochromis niloticus). Protein Expr Purif 2024; 215:106412. [PMID: 38104792 DOI: 10.1016/j.pep.2023.106412] [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: 08/30/2023] [Revised: 11/30/2023] [Accepted: 12/01/2023] [Indexed: 12/19/2023]
Abstract
Aeromonas veronii is an emerging bacterial pathogen that causes serious systemic infections in cultured Nile tilapia (Oreochromis niloticus), leading to massive deaths. Therefore, there is an urgent need to identify effective vaccine candidates to control the spread of this emerging disease. TonB-dependent receptor (Tdr) of A. veronii, which plays a role in the virulence factor of the organism, could be useful in terms of protective antigens for vaccine development. This study aims to evaluate the potential use of Tdr protein as a novel subunit vaccine against A. veronii infection in Nile tilapia. The Tdr gene from A. veronii was cloned into the pET28b expression vector, and the recombinant protein was subsequently produced in Escherichia coli strain BL21 (DE3). Tdr was expressed as an insoluble protein and purified by affinity chromatography. Antigenicity test indicated that this protein was recognized by serum from A. veronii infected fish. When Nile tilapia were immunized with the Tdr protein, specific antibody levels increased significantly (p-value <0.05) at 7 days post-immunization (dpi), and peaked at 21 dpi compared to antibody levels at 0 dpi. Furthermore, bacterial agglutination activity was observed in the fish serum immunized with the Tdr protein, indicating that specific antibodies in the serum can detect Tdr on the bacterial cell surface. These results suggest that Tdr protein has potential as a vaccine candidate. However, challenging tests with A.veronii in Nile tilapia needs to be investigated to thoroughly evaluate its protective efficacy for future applications.
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Affiliation(s)
- Pornpavee Saichuer
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand
| | - Prit Khrisanapant
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand
| | - Saengchan Senapin
- Fish Health Platform, Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp), Faculty of Science, Mahidol University, Bangkok, 10400, Thailand; National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathumthani, 12120, Thailand
| | - Triwit Rattanarojpong
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand
| | - Wasusit Somsoros
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand
| | - Pongsak Khunrae
- Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand.
| | - Pakkakul Sangsuriya
- Aquatic Molecular Genetics and Biotechnology Research Team, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathumthani, 12120, Thailand.
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30
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Zhao X, Wang W, Zeng X, Xu R, Yuan B, Yu W, Wang M, Jia R, Chen S, Zhu D, Liu M, Yang Q, Wu Y, Zhang S, Huang J, Ou X, Sun D, Cheng A. Klebicin E, a pore-forming bacteriocin of Klebsiella pneumoniae, exploits the porin OmpC and the Ton system for translocation. J Biol Chem 2024; 300:105694. [PMID: 38301890 PMCID: PMC10906532 DOI: 10.1016/j.jbc.2024.105694] [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: 09/21/2023] [Revised: 01/09/2024] [Accepted: 01/15/2024] [Indexed: 02/03/2024] Open
Abstract
Bacteriocins, which have narrow-spectrum activity and limited adverse effects, are promising alternatives to antibiotics. In this study, we identified klebicin E (KlebE), a small bacteriocin derived from Klebsiella pneumoniae. KlebE exhibited strong efficacy against multidrug-resistant K. pneumoniae isolates and conferred a significant growth advantage to the producing strain during intraspecies competition. A giant unilamellar vesicle leakage assay demonstrated the unique membrane permeabilization effect of KlebE, suggesting that it is a pore-forming toxin. In addition to a C-terminal toxic domain, KlebE also has a disordered N-terminal domain and a globular central domain. Pulldown assays and soft agar overlay experiments revealed the essential role of the outer membrane porin OmpC and the Ton system in KlebE recognition and cytotoxicity. Strong binding between KlebE and both OmpC and TonB was observed. The TonB-box, a crucial component of the toxin-TonB interaction, was identified as the 7-amino acid sequence (E3ETLTVV9) located in the N-terminal region. Further studies showed that a region near the bottom of the central domain of KlebE plays a primary role in recognizing OmpC, with eight residues surrounding this region identified as essential for KlebE toxicity. Finally, based on the discrepancies in OmpC sequences between the KlebE-resistant and sensitive strains, it was found that the 91st residue of OmpC, an aspartic acid residue, is a key determinant of KlebE toxicity. The identification and characterization of this toxin will facilitate the development of bacteriocin-based therapies targeting multidrug-resistant K. pneumoniae infections.
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Affiliation(s)
- Xinxin Zhao
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People's Republic of China, Chengdu, Sichuan, China
| | - Wenyu Wang
- Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xiaoli Zeng
- Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Rong Xu
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China
| | - Bing Yuan
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China
| | - Wenyao Yu
- Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Mingshu Wang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People's Republic of China, Chengdu, Sichuan, China
| | - Renyong Jia
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People's Republic of China, Chengdu, Sichuan, China
| | - Shun Chen
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People's Republic of China, Chengdu, Sichuan, China
| | - Dekang Zhu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People's Republic of China, Chengdu, Sichuan, China
| | - Mafeng Liu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People's Republic of China, Chengdu, Sichuan, China
| | - Qiao Yang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People's Republic of China, Chengdu, Sichuan, China
| | - Ying Wu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People's Republic of China, Chengdu, Sichuan, China
| | - Shaqiu Zhang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Juan Huang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People's Republic of China, Chengdu, Sichuan, China
| | - Xumin Ou
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People's Republic of China, Chengdu, Sichuan, China
| | - Di Sun
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People's Republic of China, Chengdu, Sichuan, China
| | - Anchun Cheng
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Chengdu, Sichuan, China; Institute of Veterinary Medicine and Immunology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China; Engineering Research Center of Southwest Animal Disease Prevention and Control Technology, Ministry of Education of the People's Republic of China, Chengdu, Sichuan, China.
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31
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Loll PJ, Grasty KC, Shultis DD, Guzman NJ, Wiener MC. Discovery and structural characterization of the D-box, a conserved TonB motif that couples an inner-membrane motor to outer-membrane transport. J Biol Chem 2024; 300:105723. [PMID: 38311172 PMCID: PMC10907165 DOI: 10.1016/j.jbc.2024.105723] [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: 01/07/2024] [Revised: 01/26/2024] [Accepted: 01/28/2024] [Indexed: 02/10/2024] Open
Abstract
Gram-negative bacteria use TonB-dependent transport to take up nutrients from the external environment, employing the Ton complex to import a variety of nutrients that are either scarce or too large to cross the outer membrane unaided. The Ton complex contains an inner-membrane motor (ExbBD) that generates force, as well as nutrient-specific transport proteins on the outer membrane. These two components are coupled by TonB, which transmits the force from the inner to the outer membrane. TonB contains an N-terminus anchored in the inner membrane, a C-terminal domain that binds the outer-membrane transporter, and a proline-rich linker connecting the two. While much is known about the interaction between TonB and outer-membrane transporters, the critical interface between TonB and ExbBD is less well understood. Here, we identify a conserved motif within TonB that we term the D-box, which serves as an attachment point for ExbD. We characterize the interaction between ExbD and the D-box both functionally and structurally, showing that a homodimer of ExbD captures one copy of the D-box peptide via beta-strand recruitment. We additionally show that both the D-box motif and ExbD are conserved in a range of Gram-negative bacteria, including members of the ESKAPE group of pathogens. The ExbD:D-box interaction is likely to represent an important aspect of force transduction between the inner and outer membranes. Given that TonB-dependent transport is an important contributor to virulence, this interaction is an intriguing potential target for novel antibacterial therapies.
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Affiliation(s)
- Patrick J Loll
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.
| | - Kimberly C Grasty
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - David D Shultis
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
| | - Nicholas J Guzman
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Michael C Wiener
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA.
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Graf J, Fresenborg L, Seitz HM, Pernil R, Schleiff E. A cobalt concentration sensitive Btu-like system facilitates cobalamin uptake in Anabaena sp. PCC 7120. MICROBIAL CELL (GRAZ, AUSTRIA) 2024; 11:41-56. [PMID: 38379927 PMCID: PMC10878165 DOI: 10.15698/mic2024.02.814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 12/21/2023] [Accepted: 01/09/2024] [Indexed: 02/22/2024]
Abstract
Metal homeostasis is central to all forms of life, as metals are essential micronutrients with toxic effects at elevated levels. Macromolecular machines facilitate metal uptake into the cells and their intracellular level is regulated by multiple means, which can involve RNA elements and proteinaceous components. While the general principles and components for uptake and cellular content regulation of, e.g., cobalt have been identified for proteobacteria, the corresponding mechanism in other Gram-negative bacteria such as cyanobacteria remain to be established. Based on their photosynthetic activity, cyanobacteria are known to exhibit a special metal demand in comparison to other bacteria. Here, the regulation by cobalt and cobalamin as well as their uptake is described for Anabaena sp. PCC 7120, a model filamentous heterocyst-forming cyanobacterium. Anabaena contains at least three cobalamin riboswitches in its genome, for one of which the functionality is confirmed here. Moreover, two outer membrane-localized cobalamin TonB-dependent transporters, namely BtuB1 and BtuB2, were identified. BtuB2 is important for fast uptake of cobalamin under conditions with low external cobalt, whereas BtuB1 appears to function in cobalamin uptake under conditions of sufficient cobalt supply. While the general function is comparable, the specific function of the two genes differs and mutants thereof show distinct phenotypes. The uptake of cobalamin depends further on the TonB and a BtuFCD machinery, as mutants of tonB3 and btuD show reduced cobalamin uptake rates. Thus, our results provide novel information on the uptake of cobalamin and the regulation of the cellular cobalt content in cyanobacteria.
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Affiliation(s)
- Julia Graf
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438 Frankfurt, Germany
| | - Leonard Fresenborg
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438 Frankfurt, Germany
- Frankfurt Isotope and Element Research Center, Goethe University Frankfurt, 60438 Frankfurt Germany
| | - Hans-Michael Seitz
- Frankfurt Isotope and Element Research Center, Goethe University Frankfurt, 60438 Frankfurt Germany
- Institute for Geoscience, Goethe University Frankfurt, Altenhöferallee 1, 60438 Frankfurt, Germany
| | - Rafael Pernil
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438 Frankfurt, Germany
| | - Enrico Schleiff
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438 Frankfurt, Germany
- Frankfurt Isotope and Element Research Center, Goethe University Frankfurt, 60438 Frankfurt Germany
- Frankfurt Institute for Advanced Studies, Ruth-Moufang-Straβe 1, 60438 Frankfurt, Germany
- Buchmann Institute for Molecular Life Sciences, Max von Laue Str. 11, 60438 Frankfurt, Germany
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Banchi E, Corre E, Del Negro P, Celussi M, Malfatti F. Genome-resolved metagenomics of Venice Lagoon surface sediment bacteria reveals high biosynthetic potential and metabolic plasticity as successful strategies in an impacted environment. MARINE LIFE SCIENCE & TECHNOLOGY 2024; 6:126-142. [PMID: 38433960 PMCID: PMC10902248 DOI: 10.1007/s42995-023-00192-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 09/05/2023] [Indexed: 03/05/2024]
Abstract
Bacteria living in sediments play essential roles in marine ecosystems and deeper insights into the ecology and biogeochemistry of these largely unexplored organisms can be obtained from 'omics' approaches. Here, we characterized metagenome-assembled-genomes (MAGs) from the surface sediment microbes of the Venice Lagoon (northern Adriatic Sea) in distinct sub-basins exposed to various natural and anthropogenic pressures. MAGs were explored for biodiversity, major marine metabolic processes, anthropogenic activity-related functions, adaptations at the microscale, and biosynthetic gene clusters. Starting from 126 MAGs, a non-redundant dataset of 58 was compiled, the majority of which (35) belonged to (Alpha- and Gamma-) Proteobacteria. Within the broad microbial metabolic repertoire (including C, N, and S metabolisms) the potential to live without oxygen emerged as one of the most important features. Mixotrophy was also found as a successful lifestyle. Cluster analysis showed that different MAGs encoded the same metabolic patterns (e.g., C fixation, sulfate oxidation) thus suggesting metabolic redundancy. Antibiotic and toxic compounds resistance genes were coupled, a condition that could promote the spreading of these genetic traits. MAGs showed a high biosynthetic potential related to antimicrobial and biotechnological classes and to organism defense and interactions as well as adaptive strategies for micronutrient uptake and cellular detoxification. Our results highlighted that bacteria living in an impacted environment, such as the surface sediments of the Venice Lagoon, may benefit from metabolic plasticity as well as from the synthesis of a wide array of secondary metabolites, promoting ecosystem resilience and stability toward environmental pressures. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-023-00192-z.
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Affiliation(s)
- Elisa Banchi
- National Institute of Oceanography and Applied Geophysics OGS, Trieste, Italy
| | - Erwan Corre
- FR2424, Station Biologique de Roscoff, Plateforme ABiMS (Analysis and Bioinformatics for Marine Science), Sorbonne Université CNRS, 29680 Roscoff, France
| | - Paola Del Negro
- National Institute of Oceanography and Applied Geophysics OGS, Trieste, Italy
| | - Mauro Celussi
- National Institute of Oceanography and Applied Geophysics OGS, Trieste, Italy
| | - Francesca Malfatti
- National Institute of Oceanography and Applied Geophysics OGS, Trieste, Italy
- Department of Life Sciences, University of Trieste, Trieste, Italy
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Tsylents U, Burmistrz M, Wojciechowska M, Stępień J, Maj P, Trylska J. Iron uptake pathway of Escherichia coli as an entry route for peptide nucleic acids conjugated with a siderophore mimic. Front Microbiol 2024; 15:1331021. [PMID: 38357356 PMCID: PMC10864483 DOI: 10.3389/fmicb.2024.1331021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/09/2024] [Indexed: 02/16/2024] Open
Abstract
Bacteria secrete various iron-chelators (siderophores), which scavenge Fe3+ from the environment, bind it with high affinity, and retrieve it inside the cell. After the Fe3+ uptake, bacteria extract the soluble iron(II) from the siderophore. Ferric siderophores are transported inside the cell via the TonB-dependent receptor system. Importantly, siderophore uptake paths have been also used by sideromycins, natural antibiotics. Our goal is to hijack the transport system for hydroxamate-type siderophores to deliver peptide nucleic acid oligomers into Escherichia coli cells. As siderophore mimics we designed and synthesized linear and cyclic Nδ-acetyl-Nδ-hydroxy-l-ornithine based peptides. Using circular dichroism spectroscopy, we found that iron(III) is coordinated by the linear trimer with hydroxamate groups but not by the cyclic peptide. The internal flexibility of the linear siderophore oxygen atoms and their interactions with Fe3+ were confirmed by all-atom molecular dynamics simulations. Using flow cytometry we found that the designed hydroxamate trimer transports PNA oligomers inside the E. coli cells. Growth recovery assays on various E. coli mutants suggest the pathway of this transport through the FhuE outer-membrane receptor, which is responsible for the uptake of the natural iron chelator, ferric-coprogen. This pathway also involves the FhuD periplasmic binding protein. Docking of the siderophores to the FhuE and FhuD receptor structures showed that binding of the hydroxamate trimer is energetically favorable corroborating the experimentally suggested uptake path. Therefore, this siderophore mimic, as well as its conjugate with PNA, is most probably internalized through the hydroxamate pathway.
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Rivera Vazquez J, Trujillo E, Williams J, She F, Getahun F, Callaghan MM, Coon JJ, Amador-Noguez D. Lipid membrane remodeling and metabolic response during isobutanol and ethanol exposure in Zymomonas mobilis. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:14. [PMID: 38281959 PMCID: PMC10823705 DOI: 10.1186/s13068-023-02450-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 12/16/2023] [Indexed: 01/30/2024]
Abstract
BACKGROUND Recent engineering efforts have targeted the ethanologenic bacterium Zymomonas mobilis for isobutanol production. However, significant hurdles remain due this organism's vulnerability to isobutanol toxicity, adversely affecting its growth and productivity. The limited understanding of the physiological impacts of isobutanol on Z. mobilis constrains our ability to overcome these production barriers. RESULTS We utilized a systems-level approach comprising LC-MS/MS-based lipidomics, metabolomics, and shotgun proteomics, to investigate how exposure to ethanol and isobutanol impact the lipid membrane composition and overall physiology of Z. mobilis. Our analysis revealed significant and distinct alterations in membrane phospholipid and fatty acid composition resulting from ethanol and isobutanol exposure. Notably, ethanol exposure increased membrane cyclopropane fatty acid content and expression of cyclopropane fatty acid (CFA) synthase. Surprisingly, isobutanol decreased cyclopropane fatty acid content despite robust upregulation of CFA synthase. Overexpression of the native Z. mobilis' CFA synthase increased cyclopropane fatty acid content in all phospholipid classes and was associated with a significant improvement in growth rates in the presence of added ethanol and isobutanol. Heterologous expression of CFA synthase from Clostridium acetobutylicum resulted in a near complete replacement of unsaturated fatty acids with cyclopropane fatty acids, affecting all lipid classes. However, this did not translate to improved growth rates under isobutanol exposure. Correlating with its greater susceptibility to isobutanol, Z. mobilis exhibited more pronounced alterations in its proteome, metabolome, and overall cell morphology-including cell swelling and formation of intracellular protein aggregates -when exposed to isobutanol compared to ethanol. Isobutanol triggered a broad stress response marked by the upregulation of heat shock proteins, efflux transporters, DNA repair systems, and the downregulation of cell motility proteins. Isobutanol also elicited widespread dysregulation of Z. mobilis' primary metabolism evidenced by increased levels of nucleotide degradation intermediates and the depletion of biosynthetic and glycolytic intermediates. CONCLUSIONS This study provides a comprehensive, systems-level evaluation of the impact of ethanol and isobutanol exposure on the lipid membrane composition and overall physiology of Z. mobilis. These findings will guide engineering of Z. mobilis towards the creation of isobutanol-tolerant strains that can serve as robust platforms for the industrial production of isobutanol from lignocellulosic sugars.
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Affiliation(s)
- Julio Rivera Vazquez
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, 53726, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
| | - Edna Trujillo
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, 53726, USA
- Genome Center of Wisconsin, Madison, WI, USA
| | - Jonathan Williams
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, 53726, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
| | - Fukang She
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
| | - Fitsum Getahun
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, 53726, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
| | - Melanie M Callaghan
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, 53726, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
| | - Joshua J Coon
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, 53726, USA
- Morgridge Institute for Research, Madison, WI, USA
- National Center for Quantitative Biology of Complex Systems, University of Wisconsin-Madison, Madison, WI, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Daniel Amador-Noguez
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, 53726, USA.
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA.
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Graf J, Schöpperle M, Pernil R, Schleiff E. Two TonB-dependent outer membrane transporters involved in heme uptake in Anabaena sp. PCC 7120. MICROBIAL CELL (GRAZ, AUSTRIA) 2024; 11:16-28. [PMID: 38234586 PMCID: PMC10792254 DOI: 10.15698/mic2024.01.812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 11/03/2023] [Accepted: 11/13/2023] [Indexed: 01/19/2024]
Abstract
Low availability of micronutrients such as iron has enforced the evolution of uptake systems in all kingdoms of life. In Gram-negative bacteria, outer membrane, periplasmatic and plasma membrane localized proteins facilitate the uptake of iron-loaded chelators, which are energized by TonB proteins. The specificity of different uptake systems likely depends either on the endogenously produced siderophore or on the bioavailability of iron-chelator complexes in the environment. Hence, an uptake system for schizokinen produced by the model cyanobacterium Anabaena sp. PCC 7120 exists, while bioinformatics analysis suggests the existence of additional systems, likely for uptake of xenosiderophores. Consistently, proteins encoded by alr2153 (hutA1) and alr3242 (hutA2) are assigned as outer membrane heme transporters. Indeed, Anabaena sp. PCC 7120 can utilize external heme as an iron source. The addition of heme resulted in an induction of genes involved in heme degradation and chlorophyll a synthesis and in an increase of the chlorophyll a content. Moreover, iron starvation induced the expression of hutA1, while the addition of heme led to its repression. Remarkably, the addition of a high concentration of heme but not iron starvation resulted in hutA2 induction. Plasmid insertion mutants of both genes exhibited a reduced capacity to recover from iron starvation by heme addition, which indicates a dependence of heme uptake on functional HutA1 and HutA2 proteins. The structural model generated by bioinformatics methods is further in agreement with a role in heme uptake. Thus, we provide evidence that Anabaena sp. PCC 7120 uses a heme uptake system in parallel to other iron acquisition systems.
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Affiliation(s)
- Julia Graf
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438 Frankfurt, Germany
| | - Martin Schöpperle
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438 Frankfurt, Germany
- Current address: Lonza Cologne GmbH, Köln, Germany:
| | - Rafael Pernil
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438 Frankfurt, Germany
| | - Enrico Schleiff
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max von Laue Str. 9, 60438 Frankfurt, Germany
- Frankfurt Institute for Advanced Studies, Ruth-Moufang-Straße 1, 60438 Frankfurt, Germany
- Buchmann Institute for Molecular Life Sciences, Max von Laue Str. 11, 60438 Frankfurt, Germany
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37
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Du X, Liu N, Yan B, Li Y, Liu M, Huang Y. Proximity-based defensive mutualism between Streptomyces and Mesorhizobium by sharing and sequestering iron. THE ISME JOURNAL 2024; 18:wrad041. [PMID: 38366066 PMCID: PMC10881299 DOI: 10.1093/ismejo/wrad041] [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: 11/01/2023] [Revised: 12/25/2023] [Accepted: 12/26/2024] [Indexed: 02/18/2024]
Abstract
Microorganisms living in soil maintain intricate interactions among themselves, forming the soil microbiota that influences the rhizosphere microbiome and plant growth. However, the mechanisms underlying the soil microbial interactions remain unclear. Streptomyces and Mesorhizobium are commonly found in soil and serve as plant growth-promoting rhizobacteria (PGPR). Here, we identified an unprecedented interaction between the colonies of red-soil-derived Streptomyces sp. FXJ1.4098 and Mesorhizobium sp. BAC0120 and referred to it as "proximity-based defensive mutualism (PBDM)." We found that metabolite-mediated iron competition and sharing between the two microorganisms were responsible for PBDM. Streptomyces sp. FXJ1.4098 produced a highly diffusible siderophore, desferrioxamine, which made iron unavailable to co-cultured Mesorhizobium sp. BAC0120, thereby inhibiting its growth. Streptomyces sp. FXJ1.4098 also released poorly diffusible iron-porphyrin complexes, which could be utilized by Mesorhizobium sp. BAC0120, thereby restoring the growth of nearby Mesorhizobium sp. BAC0120. Furthermore, in ternary interactions, the PBDM strategy contributed to the protection of Mesorhizobium sp. BAC0120 close to Streptomyces sp. FXJ1.4098 from other microbial competitors, resulting in the coexistence of these two PGPR. A scale-up pairwise interaction screening suggested that the PBDM strategy may be common between Mesorhizobium and red-soil-derived Streptomyces. These results demonstrate the key role of iron in complex microbial interactions and provide novel insights into the coexistence of PGPR in soil.
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Affiliation(s)
- Xueyuan Du
- State Key Laboratory of Microbial Resources, Chinese Academy of Sciences, Institute of Microbiology, Beijing 100101, P. R. China
- College of Life Sciences, University of Chinese Academy of Sciences , Beijing 101408, P. R. China
- National Engineering Laboratory for Site Remediation Technologies, BCEG Environmental Remediation Co., Ltd., Beijing 100015, P. R. China
| | - Ning Liu
- State Key Laboratory of Microbial Resources, Chinese Academy of Sciences, Institute of Microbiology, Beijing 100101, P. R. China
| | - Bingfa Yan
- State Key Laboratory of Microbial Resources, Chinese Academy of Sciences, Institute of Microbiology, Beijing 100101, P. R. China
- College of Life Sciences, University of Chinese Academy of Sciences , Beijing 101408, P. R. China
| | - Yisong Li
- School of Public Health, Qingdao University, Qingdao 266071, P. R. China
| | - Minghao Liu
- State Key Laboratory of Microbial Resources, Chinese Academy of Sciences, Institute of Microbiology, Beijing 100101, P. R. China
| | - Ying Huang
- State Key Laboratory of Microbial Resources, Chinese Academy of Sciences, Institute of Microbiology, Beijing 100101, P. R. China
- College of Life Sciences, University of Chinese Academy of Sciences , Beijing 101408, P. R. China
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Zinke M, Lejeune M, Mechaly A, Bardiaux B, Boneca IG, Delepelaire P, Izadi-Pruneyre N. Ton motor conformational switch and peptidoglycan role in bacterial nutrient uptake. Nat Commun 2024; 15:331. [PMID: 38184686 PMCID: PMC10771500 DOI: 10.1038/s41467-023-44606-z] [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: 07/20/2023] [Accepted: 12/20/2023] [Indexed: 01/08/2024] Open
Abstract
Active nutrient uptake is fundamental for survival and pathogenicity of Gram-negative bacteria, which operate a multi-protein Ton system to transport essential nutrients like metals and vitamins. This system harnesses the proton motive force at the inner membrane to energize the import through the outer membrane, but the mechanism of energy transfer remains enigmatic. Here, we study the periplasmic domain of ExbD, a crucial component of the proton channel of the Ton system. We show that this domain is a dynamic dimer switching between two conformations representing the proton channel's open and closed states. By in vivo phenotypic assays we demonstrate that this conformational switch is essential for the nutrient uptake by bacteria. The open state of ExbD triggers a disorder to order transition of TonB, enabling TonB to supply energy to the nutrient transporter. We also reveal the anchoring role of the peptidoglycan layer in this mechanism. Herein, we propose a mechanistic model for the Ton system, emphasizing ExbD duality and the pivotal catalytic role of peptidoglycan. Sequence analysis suggests that this mechanism is conserved in other systems energizing gliding motility and membrane integrity. Our study fills important gaps in understanding bacterial motor mechanism and proposes novel antibacterial strategies.
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Affiliation(s)
- Maximilian Zinke
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Bacterial Transmembrane Systems Unit, F-75015, Paris, France
| | - Maylis Lejeune
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Bacterial Transmembrane Systems Unit, F-75015, Paris, France
| | - Ariel Mechaly
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Crystallography Platform, F-75015, Paris, France
| | - Benjamin Bardiaux
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Bacterial Transmembrane Systems Unit, F-75015, Paris, France
| | - Ivo Gomperts Boneca
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, INSERM U1306, Unité de Biologie et génétique de la paroi bactérienne, F-75015, Paris, France
| | - Philippe Delepelaire
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, Université Paris Cité, UMR7099 CNRS, F-75005, Paris, France
- Institut de Biologie Physico-Chimique, F-75005, Paris, France
| | - Nadia Izadi-Pruneyre
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Bacterial Transmembrane Systems Unit, F-75015, Paris, France.
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Li S, Yang W, Mo J, Wang Y, Lu C, Gao Y, Li Y, Sun K. Adaptive responses and metabolic strategies of Novosphingobium sp. ES2-1-17β-estradiol analyzed through integration of genomic and proteomic approaches. JOURNAL OF HAZARDOUS MATERIALS 2024; 461:132543. [PMID: 37717446 DOI: 10.1016/j.jhazmat.2023.132543] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 09/03/2023] [Accepted: 09/11/2023] [Indexed: 09/19/2023]
Abstract
Environmental 17β-estradiol (E2) can cause potential harm to ecological balance and human health. Novosphingobium sp. ES2-1 is an E2-degrading bacterium previously obtained, which converts E2 to estrone (E1) and then to 4-hydroxyestrone (4-OH-E1) followed by oxidation to form metabolites with long-chain structure during upstream degradation. Herein, we found that intracellular enzymes were the major contributors to E2 biodegradation by strain ES2-1. A total of 243 proteins were dys-expressed under E2 condition, 123 were up-regulated and 120 were down-regulated thereinto. The up-regulated members of ABC transport systems, aromatics degradation, and fatty acid degradation indicated a reinforced transfer and utilization of E2. Cytochrome P450 monooxygenase (EstP1), 2-keto-4-pentenoate hydratase, pyruvate dehydrogenase, acetyl-CoA acetyltransferase, TonB-dependent receptor were involved in E2 catabolism. During downstream degradation, the metabolites with long-chain structure were decomposed adopting β-oxidation pattern and ultimately entered the TCA cycle; 2-keto-4-pentenoic acid might be an emblematic product of such process. Furthermore, E2 converting to E1 was catalyzed by 17β-dehydrogenase probably encoded by IM701_16645 or IM701_16910; 4-OH-E1 meta-cleavage was catalyzed by a dioxygenase encoded by IM701_20340 or IM701_21000 or IM701_09625. Our study provided an in-depth insight into the adaptive responses and metabolic strategies of Novosphingobium to E2.
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Affiliation(s)
- Shunyao Li
- Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration, Anhui University, Jiulong Road 111, Hefei 230601, China.
| | - Wei Yang
- Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration, Anhui University, Jiulong Road 111, Hefei 230601, China
| | - Jingjing Mo
- Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration, Anhui University, Jiulong Road 111, Hefei 230601, China
| | - Yubing Wang
- Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration, Anhui University, Jiulong Road 111, Hefei 230601, China
| | - Chao Lu
- National Agricultural Experimental Station for Agricultural Environment, Luhe, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, PR China
| | - Yanzheng Gao
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Yucheng Li
- Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration, Anhui University, Jiulong Road 111, Hefei 230601, China
| | - Kai Sun
- Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, Anhui, China.
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40
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Hernandez JA, Micus PS, Sunga SAL, Mazzei L, Ciurli S, Meloni G. Metal selectivity and translocation mechanism characterization in proteoliposomes of the transmembrane NiCoT transporter NixA from Helicobacter pylori. Chem Sci 2024; 15:651-665. [PMID: 38179545 PMCID: PMC10762997 DOI: 10.1039/d3sc05135h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 11/29/2023] [Indexed: 01/06/2024] Open
Abstract
Essential trace metals play key roles in the survival, replication, and virulence of bacterial pathogens. Helicobacter pylori (H. pylori), the main bacterial cause of gastric ulcers, requires Ni(ii) to colonize and persist in the acidic environment inside the stomach, exploiting the nickel-containing enzyme urease to catalyze the hydrolysis of urea to ammonia and bicarbonate and create a pH-buffered microenvironment. Urease utilizes Ni(ii) as a catalytic cofactor for its activity. In ureolytic bacteria, unique transmembrane (TM) transporters evolved to guarantee the selective uptake and efflux of Ni(ii) across cellular membranes to meet the cellular requirements. NixA is an essential Ni(ii) transporter expressed by H. pylori when the extracellular environment experiences a drop in pH. This Class I nickel-cobalt transporter of the NiCoT family catalyzes the uptake of Ni(ii) across the inner membrane from the periplasm. In this study, we characterized NixA using a platform whereby, for the first time on a NiCoT transporter, recombinantly expressed and purified NixA and key mutants in the translocation pathway have been reconstituted in artificial lipid bilayer vesicles (proteoliposomes). Fluorescent sensors responsive to Ni(ii) transport (Fluozin-3-Zn(ii)), luminal pH changes (pyranine), and membrane potential (oxonol VI) were encapsulated in the proteoliposomes lumen to monitor, in real-time, NixA transport properties and translocation mechanism. Kinetic transport analysis revealed that NixA is highly selective for Ni(ii) with no substrate promiscuity towards Co(ii), the other putative metal substrate of the NiCoT family, nor Zn(ii). NixA-mediated Ni(ii) transport exhibited a Michaelis-Menten-type saturable substrate concentration dependence, with an experimental KM, Ni(ii) = 31.0 ± 1.2 μM. Ni(ii) transport by NixA was demonstrated to be electrogenic, and metal translocation did not require a proton motive force, resulting in the generation of a positive-inside transmembrane potential in the proteoliposome lumen. Mutation analysis characterized key transmembrane residues for substrate recognition, binding, and/or transport, suggesting the presence of a three-step transmembrane translocation conduit. Taken together, these investigations reveal that NixA is a Ni(ii)-selective Class I NiCoT electrogenic uniporter. The work also provides an in vitro approach to characterize the transport properties of metal transporters responsible for Ni(ii) acquisition and extrusion in prokaryotes.
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Affiliation(s)
- Jayoh A Hernandez
- Department of Chemistry and Biochemistry, The University of Texas at Dallas Richardson TX 75080 USA
| | - Paul S Micus
- Department of Chemistry and Biochemistry, The University of Texas at Dallas Richardson TX 75080 USA
| | - Sean Alec Lois Sunga
- Department of Chemistry and Biochemistry, The University of Texas at Dallas Richardson TX 75080 USA
| | - Luca Mazzei
- Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology, University of Bologna Bologna I-40127 Italy
| | - Stefano Ciurli
- Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology, University of Bologna Bologna I-40127 Italy
| | - Gabriele Meloni
- Department of Chemistry and Biochemistry, The University of Texas at Dallas Richardson TX 75080 USA
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41
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Hussein SM, Sofoluwe A, Paleja A, Duhme-Klair A, Thomas MS. Identification of a system for hydroxamate xenosiderophore-mediated iron transport in Burkholderia cenocepacia. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001425. [PMID: 38189440 PMCID: PMC10866019 DOI: 10.1099/mic.0.001425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 12/19/2023] [Indexed: 01/09/2024]
Abstract
One of the mechanisms employed by the opportunistic pathogen Burkholderia cenocepacia to acquire the essential element iron is the production and release of two ferric iron chelating compounds (siderophores), ornibactin and pyochelin. Here we show that B. cenocepacia is also able to take advantage of a range of siderophores produced by other bacteria and fungi ('xenosiderophores') that chelate iron exclusively by means of hydroxamate groups. These include the tris-hydroxamate siderophores ferrioxamine B, ferrichrome, ferricrocin and triacetylfusarinine C, the bis-hydroxamates alcaligin and rhodotorulic acid, and the monohydroxamate siderophore cepabactin. We also show that of the 24 TonB-dependent transporters encoded by the B. cenocepacia genome, two (FhuA and FeuA) are involved in the uptake of hydroxamate xenosiderophores, with FhuA serving as the exclusive transporter of iron-loaded ferrioxamine B, triacetylfusarinine C, alcaligin and rhodotorulic acid, while both FhuA and FeuA are able to translocate ferrichrome-type siderophores across the outer membrane. Finally, we identified FhuB, a putative cytoplasmic membrane-anchored ferric-siderophore reductase, as being obligatory for utilization of all of the tested bis- and tris-hydroxamate xenosiderophores apart from alcaligin.
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Affiliation(s)
- Syakira Mohammed Hussein
- Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Medical School, Beech Hill Road, Sheffield S10 2RX, UK
| | - Aderonke Sofoluwe
- Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Medical School, Beech Hill Road, Sheffield S10 2RX, UK
- Department of Immunobiology, School of Immunology & Microbial Sciences, King’s College London, London WC2R 2LS, UK
| | - Ameya Paleja
- Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Medical School, Beech Hill Road, Sheffield S10 2RX, UK
| | - Anne Duhme-Klair
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Mark S. Thomas
- Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Medical School, Beech Hill Road, Sheffield S10 2RX, UK
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42
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Smith P, Schuster M. The fitness benefit of pyoverdine cross-feeding by Pseudomonas protegens Pf-5. Environ Microbiol 2024; 26:e16554. [PMID: 38097191 DOI: 10.1111/1462-2920.16554] [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: 09/19/2023] [Accepted: 11/24/2023] [Indexed: 12/20/2023]
Abstract
Under iron-limiting conditions, fluorescent pseudomonads acquire iron from the environment by secreting strain-specific, iron-chelating siderophores termed pyoverdines (PVD). The rhizosphere bacterium Pseudomonas protegens Pf-5 produces its own PVD but also can cross-feed on PVDs produced by other species. Previous work has found that Pf-5 continues to produce its own PVD when allowed to cross-feed, raising questions about the benefit of heterologous PVD utilisation. Here, we investigate this question using a defined, unidirectional P. protegens Pf-5/Pseudomonas aeruginosa PAO1 cross-feeding model. Quantifying the production of PVD in the presence of heterologous PVD produced by PAO1, we show that cross-feeding Pf-5 strains reduce the production of their own PVD, while non-cross-feeding Pf-5 strains increase the production of PVD. Measuring the fitness of cross-feeding and non-cross-feeding Pf-5 strains in triple coculture with PAO1, we find that cross-feeding provides a fitness benefit to Pf-5 when the availability of heterologous PVD is high. We conclude that cross-feeding can reduce the costs of self-PVD production and may thus aid in the colonisation of iron-limited environments that contain compatible siderophores produced by other resident microbes. Taken together, these results expand our understanding of the mechanisms of interspecific competition for iron in microbial communities.
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Affiliation(s)
- Parker Smith
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
| | - Martin Schuster
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
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43
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Zou Z, Robinson JI, Steinberg LK, Henderson JP. Uropathogenic Escherichia coli wield enterobactin-derived catabolites as siderophores. J Biol Chem 2024; 300:105554. [PMID: 38072063 PMCID: PMC10788543 DOI: 10.1016/j.jbc.2023.105554] [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: 07/28/2023] [Revised: 11/20/2023] [Accepted: 12/05/2023] [Indexed: 12/19/2023] Open
Abstract
Uropathogenic Escherichia coli (UPEC) secrete multiple siderophore types to scavenge extracellular iron(III) ions during clinical urinary tract infections, despite the metabolic costs of biosynthesis. Here, we find the siderophore enterobactin (Ent) and its related products to be prominent components of the iron-responsive extracellular metabolome of a model UPEC strain. Using defined Ent biosynthesis and import mutants, we identify lower molecular weight dimeric exometabolites as products of incomplete siderophore catabolism, rather than prematurely released biosynthetic intermediates. In E. coli, iron acquisition from iron(III)-Ent complexes requires intracellular esterases that hydrolyze the siderophore. Although UPEC are equipped to consume the products of completely hydrolyzed Ent, we find that Ent and its derivatives may be incompletely hydrolyzed to yield products with retained siderophore activity. These results are consistent with catabolic inefficiency as means to obtain more than one iron ion per siderophore molecule. This is compatible with an evolved UPEC strategy to maximize the nutritional returns from metabolic investments in siderophore biosynthesis.
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Affiliation(s)
- Zongsen Zou
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - John I Robinson
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Lindsey K Steinberg
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Jeffrey P Henderson
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA.
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44
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Naka H, Haygood MG. The dual role of TonB genes in turnerbactin uptake and carbohydrate utilization in the shipworm symbiont Teredinibacter turnerae. Appl Environ Microbiol 2023; 89:e0074423. [PMID: 38009998 PMCID: PMC10734418 DOI: 10.1128/aem.00744-23] [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: 05/18/2023] [Accepted: 10/01/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE This study highlights diversity in iron acquisition and regulation in bacteria. The mechanisms of iron acquisition and its regulation in Teredinibacter turnerae, as well as its connection to cellulose utilization, a hallmark phenotype of T. turnerae, expand the paradigm of bacterial iron acquisition. Two of the four TonB genes identified in T. turnerae exhibit functional redundancy and play a crucial role in siderophore-mediated iron transport. Unlike typical TonB genes in bacteria, none of the TonB genes in T. turnerae are clearly iron regulated. This unusual regulation could be explained by another important finding in this study, namely, that the two TonB genes involved in iron transport are also essential for cellulose utilization as a carbon source, leading to the expression of TonB genes even under iron-rich conditions.
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Affiliation(s)
- Hiroaki Naka
- Department of Medicinal Chemistry, The University of Utah, Salt Lake City, Utah, USA
- Division of Genetics, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Margo G. Haygood
- Department of Medicinal Chemistry, The University of Utah, Salt Lake City, Utah, USA
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45
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Gabor CE, Hazen TH, Delaine-Elias BC, Rasko DA, Barry EM. Genomic, transcriptomic, and phenotypic differences among archetype Shigella flexneri strains of serotypes 2a, 3a, and 6. mSphere 2023; 8:e0040823. [PMID: 37830809 PMCID: PMC10732043 DOI: 10.1128/msphere.00408-23] [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: 07/25/2023] [Accepted: 08/30/2023] [Indexed: 10/14/2023] Open
Abstract
IMPORTANCE Given the genomic diversity between S. flexneri serotypes and the paucity of data to support serotype-specific phenotypic differences, we applied in silico and in vitro functional analyses of archetype strains of 2457T (Sf2a), J17B (Sf3a), and CH060 (Sf6). These archetype strains represent the three leading S. flexneri serotypes recommended for inclusion in multivalent vaccines. Characterizing the genomic and phenotypic variation among these clinically prevalent serotypes is an important step toward understanding serotype-specific host-pathogen interactions to optimize the efficacy of multivalent vaccines and therapeutics. This study underpins the importance for further large-scale serotype-targeted analyses.
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Affiliation(s)
- Caitlin E. Gabor
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Tracy H. Hazen
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - BreOnna C. Delaine-Elias
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - David A. Rasko
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Center for Pathogen Research, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Eileen M. Barry
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
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46
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LeCleir GR, Bassett J, Wilhelm SW. Effects of iron concentration and DFB (Desferrioxamine-B) on transcriptional profiles of an ecologically relevant marine bacterium. PLoS One 2023; 18:e0295257. [PMID: 38100448 PMCID: PMC10723695 DOI: 10.1371/journal.pone.0295257] [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: 04/14/2023] [Accepted: 11/20/2023] [Indexed: 12/17/2023] Open
Abstract
Research into marine iron cycles and biogeochemistry has commonly relied on the use of chelators (including siderophores) to manipulate iron bioavailability. To test whether a commonly used chelator, desferrioxamine B (DFB) caused effects beyond changing the iron-status of cells, cultures of the environmentally relevant marine heterotrophic bacterium, Ruegeria pomeroyii, were grown in media with different concentrations of iron and/or DFB, resulting in a gradient of iron availability. To determine how cells responded, transcriptomes were generated for cells from the different treatments and analyzed to determine how cells reacted to these to perturbations. Analyses were also performed to look for cellular responses specific to the presence of DFB in the culture medium. As expected, cells experiencing different levels of iron availability had different transcriptomic profiles. While many genes related to iron acquisition were differentially expressed between treatments, there were many other genes that were also differentially expressed between different sample types, including those related to the uptake and metabolism of other metals as well as genes related to metabolism of other types of molecules like amino acids and carbohydrates. We conclude that while DFB certainly altered iron availability to cells, it also appears to have had a general effect on the homeostasis of other metals as well as influenced metabolic processes outside of metal acquisition.
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Affiliation(s)
- Gary R. LeCleir
- Department of Microbiology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Jenna Bassett
- Department of Microbiology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Steven W. Wilhelm
- Department of Microbiology, The University of Tennessee, Knoxville, Tennessee, United States of America
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47
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Weng C, Tan YLK, Koh WG, Ang WH. Harnessing Transition Metal Scaffolds for Targeted Antibacterial Therapy. Angew Chem Int Ed Engl 2023; 62:e202310040. [PMID: 37621226 DOI: 10.1002/anie.202310040] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/24/2023] [Accepted: 08/24/2023] [Indexed: 08/26/2023]
Abstract
Antimicrobial resistance, caused by persistent adaptation and growing resistance of pathogenic bacteria to overprescribed antibiotics, poses one of the most serious and urgent threats to global public health. The limited pipeline of experimental antibiotics in development further exacerbates this looming crisis and new drugs with alternative modes of action are needed to tackle evolving pathogenic adaptation. Transition metal complexes can replenish this diminishing stockpile of drug candidates by providing compounds with unique properties that are not easily accessible using pure organic scaffolds. We spotlight four emerging strategies to harness these unique properties to develop new targeted antibacterial agents.
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Affiliation(s)
- Cheng Weng
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Singapore
| | | | - Wayne Gareth Koh
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Singapore
| | - Wee Han Ang
- Department of Chemistry, National University of Singapore, 4 Science Drive 2, Singapore, 117544, Singapore
- NUS Graduate School of Integrative Sciences and Engineering, 28 Medical Drive, Singapore, 117456, Singapore
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48
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Peters MK, Astafyeva Y, Han Y, Macdonald JFH, Indenbirken D, Nakel J, Virdi S, Westhoff G, Streit WR, Krohn I. Novel marine metalloprotease-new approaches for inhibition of biofilm formation of Stenotrophomonas maltophilia. Appl Microbiol Biotechnol 2023; 107:7119-7134. [PMID: 37755512 PMCID: PMC10638167 DOI: 10.1007/s00253-023-12781-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 08/30/2023] [Accepted: 09/07/2023] [Indexed: 09/28/2023]
Abstract
Many marine organisms produce bioactive molecules with unique characteristics to survive in their ecological niches. These enzymes can be applied in biotechnological processes and in the medical sector to replace aggressive chemicals that are harmful to the environment. Especially in the human health sector, there is a need for new approaches to fight against pathogens like Stenotrophomonas maltophilia which forms thick biofilms on artificial joints or catheters and causes serious diseases. Our approach was to use enrichment cultures of five marine resources that underwent sequence-based screenings in combination with deep omics analyses in order to identify enzymes with antibiofilm characteristics. Especially the supernatant of the enrichment culture of a stony coral caused a 40% reduction of S. maltophilia biofilm formation. In the presence of the supernatant, our transcriptome dataset showed a clear stress response (upregulation of transcripts for metal resistance, antitoxins, transporter, and iron acquisition) to the treatment. Further investigation of the enrichment culture metagenome and proteome indicated a series of potential antimicrobial enzymes. We found an impressive group of metalloproteases in the proteome of the supernatant that is responsible for the detected anti-biofilm effect against S. maltophilia. KEY POINTS: • Omics-based discovery of novel marine-derived antimicrobials for human health management by inhibition of S. maltophilia • Up to 40% reduction of S. maltophilia biofilm formation by the use of marine-derived samples • Metalloprotease candidates prevent biofilm formation of S. maltophilia K279a by up to 20.
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Affiliation(s)
- Marie Kristin Peters
- Department of Microbiology and Biotechnology, Institute of Plant Science and Microbiology, University of Hamburg, Ohnhorststr.18, 22609, Hamburg, Germany
| | - Yekaterina Astafyeva
- Department of Microbiology and Biotechnology, Institute of Plant Science and Microbiology, University of Hamburg, Ohnhorststr.18, 22609, Hamburg, Germany
| | - Yuchen Han
- Department of Microbiology and Biotechnology, Institute of Plant Science and Microbiology, University of Hamburg, Ohnhorststr.18, 22609, Hamburg, Germany
| | - Jascha F H Macdonald
- Department of Microbiology and Biotechnology, Institute of Plant Science and Microbiology, University of Hamburg, Ohnhorststr.18, 22609, Hamburg, Germany
| | - Daniela Indenbirken
- Technology Platform Next Generation Sequencing, Leibniz Institute of Virology, Martinistraße 52, 20251, Hamburg, Germany
| | - Jacqueline Nakel
- Technology Platform Next Generation Sequencing, Leibniz Institute of Virology, Martinistraße 52, 20251, Hamburg, Germany
| | - Sanamjeet Virdi
- Technology Platform Next Generation Sequencing, Leibniz Institute of Virology, Martinistraße 52, 20251, Hamburg, Germany
| | - Guido Westhoff
- Tierpark Hagenbeck, Gemeinnützige Gesellschaft mbH, Lokstedter Grenzstraße 2, 22527, Hamburg, Germany
| | - Wolfgang R Streit
- Department of Microbiology and Biotechnology, Institute of Plant Science and Microbiology, University of Hamburg, Ohnhorststr.18, 22609, Hamburg, Germany
| | - Ines Krohn
- Department of Microbiology and Biotechnology, Institute of Plant Science and Microbiology, University of Hamburg, Ohnhorststr.18, 22609, Hamburg, Germany.
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49
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Brauner M, Briggs BR. Microbial iron acquisition is influenced by spatial and temporal conditions in a glacial influenced river and estuary system. Environ Microbiol 2023; 25:3450-3465. [PMID: 37956696 PMCID: PMC10872409 DOI: 10.1111/1462-2920.16541] [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: 01/05/2023] [Accepted: 10/31/2023] [Indexed: 11/15/2023]
Abstract
In Arctic regions, glaciers are major sources of iron to rivers and streams; however, estuaries are considered iron sinks due to the coagulation and flocculation processes that occur at higher salinities. It is unknown how iron dynamics in a glacial influenced river and estuary environment affect microbial mechanisms for iron acquisition. Microbial taxonomic and functional sequencing was performed on samples taken throughout the year from the Kenai River and the estuary, Alaska. Despite distinct iron, sodium, and other nutrient concentrations, the river and estuary did not have statistically different microbial communities nor was time of sampling significant. However, ferrous iron transport (Feo) system genes were more abundant in river environments, while siderophore genes were more abundant and diverse in estuary environments. Siderophore transport and iron storage genes were found in all samples, but gene abundance and distribution were potentially influenced by physical drivers such as discharge rates and nutrient distributions. Differences in iron metabolism between river and estuary ecosystems indicate environmental conditions drive microbial mechanisms to sequester iron. This could have implications for iron transport as the Arctic continues to warm.
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Affiliation(s)
- Megan Brauner
- Department of Biological Sciences, University of Alaska Anchorage, 3211 Providence Dr CPSB 101, Anchorage, Alaska
| | - Brandon R. Briggs
- Department of Biological Sciences, University of Alaska Anchorage, 3211 Providence Dr CPSB 101, Anchorage, Alaska
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50
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Williams-Jones DP, Webby MN, Press CE, Gradon JM, Armstrong SR, Szczepaniak J, Kleanthous C. Tunable force transduction through the Escherichia coli cell envelope. Proc Natl Acad Sci U S A 2023; 120:e2306707120. [PMID: 37972066 PMCID: PMC10666116 DOI: 10.1073/pnas.2306707120] [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: 04/28/2023] [Accepted: 09/28/2023] [Indexed: 11/19/2023] Open
Abstract
The outer membrane (OM) of Gram-negative bacteria is not energised and so processes requiring a driving force must connect to energy-transduction systems in the inner membrane (IM). Tol (Tol-Pal) and Ton are related, proton motive force- (PMF-) coupled assemblies that stabilise the OM and import essential nutrients, respectively. Both rely on proton-harvesting IM motor (stator) complexes, which are homologues of the flagellar stator unit Mot, to transduce force to the OM through elongated IM force transducer proteins, TolA and TonB, respectively. How PMF-driven motors in the IM generate mechanical work at the OM via force transducers is unknown. Here, using cryoelectron microscopy, we report the 4.3Å structure of the Escherichia coli TolQR motor complex. The structure reaffirms the 5:2 stoichiometry seen in Ton and Mot and, with motor subunits related to each other by 10 to 16° rotation, supports rotary motion as the default for these complexes. We probed the mechanism of force transduction to the OM through in vivo assays of chimeric TolA/TonB proteins where sections of their structurally divergent, periplasm-spanning domains were swapped or replaced by an intrinsically disordered sequence. We find that TolA mutants exhibit a spectrum of force output, which is reflected in their respective abilities to both stabilise the OM and import cytotoxic colicins across the OM. Our studies demonstrate that structural rigidity of force transducer proteins, rather than any particular structural form, drives the efficient conversion of PMF-driven rotary motions of 5:2 motor complexes into physiologically relevant force at the OM.
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Affiliation(s)
| | - Melissa N. Webby
- Department of Biochemistry, University of Oxford, OxfordOX1 3QU, United Kingdom
| | - Cara E. Press
- Department of Biochemistry, University of Oxford, OxfordOX1 3QU, United Kingdom
| | - Jan M. Gradon
- Department of Biochemistry, University of Oxford, OxfordOX1 3QU, United Kingdom
| | - Sophie R. Armstrong
- Department of Biochemistry, University of Oxford, OxfordOX1 3QU, United Kingdom
| | - Joanna Szczepaniak
- Department of Biochemistry, University of Oxford, OxfordOX1 3QU, United Kingdom
| | - Colin Kleanthous
- Department of Biochemistry, University of Oxford, OxfordOX1 3QU, United Kingdom
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