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Rahman ASMZ, Syroegin EA, Novomisky Nechcoff J, Devarajan A, Polikanov YS, Cardona ST. Rationally Designed Pooled CRISPRi-Seq Uncovers an Inhibitor of Bacterial Peptidyl-tRNA Hydrolase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.02.592284. [PMID: 38979387 PMCID: PMC11230203 DOI: 10.1101/2024.05.02.592284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Pooled knockdown libraries of essential genes are useful tools for elucidating the mechanisms of action of antibacterial compounds, a pivotal step in antibiotic discovery. However, achieving genomic coverage of antibacterial targets poses a challenge due to the uneven proliferation of knockdown mutants during pooled growth, leading to the unintended loss of important targets. To overcome this issue, we describe the construction of CIMPLE ( C RISPR i - m ediated p ooled library of e ssential genes), a rationally designed pooled knockdown library built in a model antibiotic-resistant bacteria, Burkholderia cenocepacia. By analyzing growth parameters of clonal knockdown populations of an arrayed CRISPRi library, we predicted strain depletion levels during pooled growth and adjusted mutant relative abundance, approaching genomic coverage of antibacterial targets during antibiotic exposure. We first benchmarked CIMPLE by chemical-genetic profiling of known antibacterials, then applied it to an uncharacterized bacterial growth inhibitor from a new class. CRISPRi-Seq with CIMPLE, followed by biochemical validation, revealed that the novel compound targets the peptidyl-tRNA hydrolase (Pth). Overall, CIMPLE leverages the advantages of arrayed and pooled CRISPRi libraries to uncover unexplored targets for antibiotic action. Summary Bacterial mutant libraries in which antibiotic targets are downregulated are useful tools to functionally characterize novel antimicrobials. These libraries are used for chemical-genetic profiling as target-compound interactions can be inferred by differential fitness of mutants during pooled growth. Mutants that are functionally related to the antimicrobial mode of action are usually depleted from the pool upon exposure to the drug. Although powerful, this method can fail when the unequal proliferation of mutant strains before exposure causes mutants to fall below the detection level in the library pool. To address this issue, we constructed an arrayed essential gene mutant library (EGML) in the antibiotic-resistant bacterium Burkholderia cenocepacia using CRISPR interference (CRISPRi) and analyzed the growth parameters of individual mutant strains. We then modelled depletion levels during pooled growth and used the model to rationally design an optimized CRISPR interference-mediated pooled library of essential genes (CIMPLE). By adjusting the initial inoculum of the knockdown mutants, we achieved coverage of the bacterial essential genome with mutant sensitization. We exposed CIMPLE to a recently discovered antimicrobial of a novel class and discovered it inhibits the peptidyl-tRNA hydrolase, an essential bacterial enzyme. In summary, we demonstrate the utility of CIMPLE and CRISPRi-Seq to uncover the mechanism of action of novel antimicrobial compounds. Graphical abstract
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Karimullina E, Guo Y, Khan HM, Emde T, Quade B, Leo RD, Otwinowski Z, Tieleman Peter D, Borek D, Savchenko A. Structural architecture of TolQ-TolR inner membrane protein complex from opportunistic pathogen Acinetobacter baumannii. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.19.599759. [PMID: 38948712 PMCID: PMC11212960 DOI: 10.1101/2024.06.19.599759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Gram-negative bacteria harness the proton motive force (PMF) within their inner membrane (IM) to uphold the integrity of their cell envelope, an indispensable aspect for both division and survival. The IM TolQ-TolR complex is the essential part of the Tol-Pal system, serving as a conduit for PMF energy transfer to the outer membrane. Here we present cryo-EM reconstructions of Acinetobacter baumannii TolQ in apo and TolR- bound forms at atomic resolution. The apo TolQ configuration manifests as a symmetric pentameric pore, featuring a trans-membrane funnel leading towards a cytoplasmic chamber. In contrast, the TolQ-TolR complex assumes a proton non-permeable stance, characterized by the TolQ pentamer's flexure to accommodate the TolR dimer, where two protomers undergo a translation-based relationship. Our structure-guided analysis and simulations support the rotor-stator mechanism of action, wherein the rotation of the TolQ pentamer harmonizes with the TolR protomers' interplay. These findings broaden our mechanistic comprehension of molecular stator units empowering critical functions within the Gram-negative bacterial cell envelope. Teaser Apo TolQ and TolQ-TolR structures depict structural rearrangements required for cell envelope organization in bacterial cell division.
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Armbruster KM, Jiang J, Sartorio MG, Scott NE, Peterson JM, Sexton JZ, Feldman MF, Koropatkin NM. Identification and Characterization of the Lipoprotein N-acyltransferase in Bacteroides. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.31.596883. [PMID: 38853980 PMCID: PMC11160734 DOI: 10.1101/2024.05.31.596883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Members of the Bacteroidota compose a large portion of the human gut microbiota, contributing to overall gut health via the degradation of various polysaccharides. This process is facilitated by lipoproteins, globular proteins anchored to the cell surface by a lipidated N-terminal cysteine. Despite their importance, lipoprotein synthesis by these bacteria is understudied. In E. coli, the α-amino linked lipid of lipoproteins is added by the lipoprotein N-acyltransferase Lnt. Herein, we have identified a protein distinct from Lnt responsible for the same process in Bacteroides, named lipoprotein N-acyltransferase in Bacteroides (Lnb). Deletion of Lnb yields cells that synthesize diacylated lipoproteins, with impacts on cell viability and morphology, growth on polysaccharides, and protein composition of membranes and outer membrane vesicles (OMVs). Our results not only challenge the accepted paradigms of lipoprotein biosynthesis in Gram-negative bacteria, but also support the establishment of a new family of lipoprotein N-acyltransferases.
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Affiliation(s)
- Krista M Armbruster
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Jiawen Jiang
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Mariana G Sartorio
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Nichollas E Scott
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Parkville, Victoria, 3000, Australia
| | - Jenna M Peterson
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Jonathan Z Sexton
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Mario F Feldman
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
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Sousa M, Oliveira IM, Correia L, Gomes IB, Sousa CA, Braga DFO, Simões M. Far-UV-C irradiation promotes synergistic bactericidal action against adhered cells of Escherichia coli and Staphylococcus epidermidis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170352. [PMID: 38286293 DOI: 10.1016/j.scitotenv.2024.170352] [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: 11/13/2023] [Revised: 01/17/2024] [Accepted: 01/20/2024] [Indexed: 01/31/2024]
Abstract
The contamination of indoor areas is a global health problem that can cause the dispersion of infectious diseases. In that sense, it is urgent to find new strategies applying a lower concentration of the traditional chemicals used for cleaning and disinfection. Ultraviolet radiation (UV), in particular far-UV-C (200-225 nm), has emerged as a successful, powerful, easy-to-apply, and inexpensive approach for bacterial eradication that still requires scientific assessment. This study investigated new strategies for disinfection based on far-UV-C (222 nm) combined with chlorine and mechanical cleaning, providing an innovative solution using low doses. The bactericidal activity of far-UV-C (222 nm) was tested at an intensity of irradiation from 78.4 μW/cm2 to 597.7 μW/cm2 (for 1 min) against Escherichia coli and Staphylococcus epidermidis adhered on polystyrene microtiter plates. It was further tested in combination with mechanical cleaning (ultrasounds for 1 min) and free chlorine (0.1, 0.5, and 1 mg/L for 5 min). The triple combination consisting of mechanical cleaning + free chlorine (0.5 mg/L) + far-UV-C (54 mJ/cm2) was tested against cells adhered to materials found in hospital settings and other public spaces: polyvinyl chloride (PVC), stainless steel (SS), and polyetheretherketone (PEEK). Disinfection with far-UV-C (54 mJ/cm2) and free chlorine at 0.5 mg/L for 5 min allowed a total reduction of culturable E. coli cells and a logarithmic reduction of 2.98 ± 0.03 for S. epidermidis. The triple combination of far-UV-C, free chlorine, and mechanical cleaning resulted in a total reduction of culturable cells for both adhered bacteria. Bacterial adhesion to PVC, SS, and PEEK occurred at distinct extents and influenced the bactericidal activity of the triple combination, with logarithmic reductions of up to three. The overall results highlight that, based on culturability assessment, far-UV-C (54 mJ/cm2) with chlorine (0.5 mg/L; 5 min) and mechanical cleaning (1 min) as an efficient disinfection strategy using mild conditions. The combination of culturability and viability assessment of disinfection is recommended to detect regrowth events and increase the effectiveness in microbial growth control.
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Affiliation(s)
- M Sousa
- LEPABE-Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, Department of Chemical Engineering, University of Porto, 4200-465 Porto, Portugal; ALiCE-Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal
| | - I M Oliveira
- LEPABE-Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, Department of Chemical Engineering, University of Porto, 4200-465 Porto, Portugal; ALiCE-Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal
| | - L Correia
- SpinnerDynamics, Lda., Rua da Junta de Freguesia 194, 4540-322 Escariz, Arouca, Portugal
| | - I B Gomes
- LEPABE-Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, Department of Chemical Engineering, University of Porto, 4200-465 Porto, Portugal; ALiCE-Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal
| | - C A Sousa
- LEPABE-Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, Department of Chemical Engineering, University of Porto, 4200-465 Porto, Portugal; ALiCE-Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal
| | - D F O Braga
- SpinnerDynamics, Lda., Rua da Junta de Freguesia 194, 4540-322 Escariz, Arouca, Portugal
| | - M Simões
- LEPABE-Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, Department of Chemical Engineering, University of Porto, 4200-465 Porto, Portugal; ALiCE-Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal.
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Chen S, Xie Z, Yang Y, Sun N, Guo Z, Li M, Wang C. A self-activating electron transfer antibacterial strategy: Co 3O 4/TiO 2 P-N heterojunctions combined with photothermal therapy. Biomater Sci 2024; 12:1573-1589. [PMID: 38319143 DOI: 10.1039/d3bm01550e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Implant-associated infections are significant impediments to successful surgical outcomes, often resulting from persistent bacterial contamination. It has been hypothesized that bacteria can transfer electrons to semiconductors with comparable potential to the biological redox potential (BRP). Building on this concept, we developed an antibiotic-free bactericidal system, Co3O4/TiO2-Ti, capable of achieving real-time and sustainable bactericidal effects. Our study demonstrated that Co3O4/TiO2-Ti, possessing an appropriately set valence band, initiated charge transfer, reactive oxygen species (ROS) production, and membrane damage in adherent Staphylococcus aureus (S. aureus). Notably, in vivo experiments illustrated the remarkable antibacterial activity of Co3O4/TiO2-Ti, while promoting soft-tissue reconstruction and demonstrating excellent cytocompatibility. Transcriptomic analysis further revealed a down-regulation of aerobic respiration-associated genes and an up-regulation of ROS-associated genes in S. aureus in the presence of Co3O4/TiO2-Ti compared to Ti. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and gene set enrichment analysis (GSEA) identified alterations in respiratory metabolism, oxidative phosphorylation, and the synthesis of amino acid in S. aureus cultured on Co3O4/TiO2-Ti. Furthermore, when combined with near-infrared (NIR) irradiation and photothermal therapy (PTT), Co3O4/TiO2-Ti eliminated 95.71% of floating and adherent S. aureus in vitro. The findings suggest that this antibiotic-free strategy holds substantial promise in enhancing implant sterilization capabilities, thereby contributing to the prevention and treatment of bacterial infections through bandgap engineering of implants and NIR irradiation.
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Affiliation(s)
- Siyuan Chen
- Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
- Jiangsu Key Laboratory of Oral Diseases, Nanjing, China
| | - Zhe Xie
- Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
- Jiangsu Key Laboratory of Oral Diseases, Nanjing, China
| | - Yuchen Yang
- Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
- Jiangsu Key Laboratory of Oral Diseases, Nanjing, China
| | - Nuo Sun
- Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
- Jiangsu Key Laboratory of Oral Diseases, Nanjing, China
| | - Zhengnong Guo
- Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
- Jiangsu Key Laboratory of Oral Diseases, Nanjing, China
| | - Miaomiao Li
- Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
- Jiangsu Key Laboratory of Oral Diseases, Nanjing, China
| | - Chen Wang
- Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China.
- Jiangsu Key Laboratory of Oral Diseases, Nanjing, China
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Govers SK, Campos M, Tyagi B, Laloux G, Jacobs-Wagner C. Apparent simplicity and emergent robustness in the control of the Escherichia coli cell cycle. Cell Syst 2024; 15:19-36.e5. [PMID: 38157847 DOI: 10.1016/j.cels.2023.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 06/15/2023] [Accepted: 12/01/2023] [Indexed: 01/03/2024]
Abstract
To examine how bacteria achieve robust cell proliferation across diverse conditions, we developed a method that quantifies 77 cell morphological, cell cycle, and growth phenotypes of a fluorescently labeled Escherichia coli strain and >800 gene deletion derivatives under multiple nutrient conditions. This approach revealed extensive phenotypic plasticity and deviating mutant phenotypes were often nutrient dependent. From this broad phenotypic landscape emerged simple and robust unifying rules (laws) that connect DNA replication initiation, nucleoid segregation, FtsZ ring formation, and cell constriction to specific aspects of cell size (volume, length, or added length) at the population level. Furthermore, completion of cell division followed the initiation of cell constriction after a constant time delay across strains and nutrient conditions, identifying cell constriction as a key control point for cell size determination. Our work provides a population-level description of the governing principles by which E. coli integrates cell cycle processes and growth rate with cell size to achieve its robust proliferative capability. A record of this paper's transparent peer review process is included in the supplemental information.
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Affiliation(s)
- Sander K Govers
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA; de Duve Institute, UCLouvain, Brussels, Belgium; Department of Biology, KU Leuven, Leuven, Belgium
| | - Manuel Campos
- Centre de Biologie Intégrative de Toulouse, Laboratoire de Microbiologie et Génétique Moléculaires, Université de Toulouse, Toulouse, France
| | - Bhavyaa Tyagi
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA; Department of Biology, Stanford University, Stanford, CA 94305, USA
| | | | - Christine Jacobs-Wagner
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA; Department of Biology, Stanford University, Stanford, CA 94305, USA; Sarafan Chemistry, Engineering Medicine for Human Health Institute, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford School of Medicine, Stanford, CA 94305, USA.
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Cebrián R, Lucas R, Fernández-Cantos MV, Slot K, Peñalver P, Martínez-García M, Párraga-Leo A, de Paz MV, García F, Kuipers OP, Morales JC. Synthesis and antimicrobial activity of aminoalkyl resveratrol derivatives inspired by cationic peptides. J Enzyme Inhib Med Chem 2023; 38:267-281. [PMID: 36600674 PMCID: PMC9828810 DOI: 10.1080/14756366.2022.2146685] [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] [Indexed: 01/06/2023] Open
Abstract
Antimicrobial resistance is a global concern, far from being resolved. The need of new drugs against new targets is imminent. In this work, we present a family of aminoalkyl resveratrol derivatives with antibacterial activity inspired by the properties of cationic amphipathic antimicrobial peptides. Surprisingly, the newly designed molecules display modest activity against aerobically growing bacteria but show surprisingly good antimicrobial activity against anaerobic bacteria (Gram-negative and Gram-positive) suggesting specificity towards this bacterial group. Preliminary studies into the action mechanism suggest that activity takes place at the membrane level, while no cross-resistance with traditional antibiotics is observed. Actually, some good synergistic relations with existing antibiotics were found against Gram-negative pathogens. However, some cytotoxicity was observed, despite their low haemolytic activity. Our results show the importance of the balance between positively charged moieties and hydrophobicity to improve antimicrobial activity, setting the stage for the design of new drugs based on these molecules.
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Affiliation(s)
- Rubén Cebrián
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands,Department of Clinical Microbiology, Instituto de Investigación Biosanitaria ibs. GRANADA, University Hospital Clínico San Cecilio, Granada, Spain,CONTACT Rubén Cebrián University Hospital San Cecilio,Clinical Microbiology Department, Av. de la Innovación s/n, 18061, Granada, Spain
| | - Ricardo Lucas
- Department of Organic and Pharmaceutical Chemistry, School of Pharmacy, University of Seville, Seville, Spain
| | - María Victoria Fernández-Cantos
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Koen Slot
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Pablo Peñalver
- Department of Biochemistry and Molecular Pharmacology, Instituto de Parasitología y Biomedicina López Neyra, CSIC, PTS Granada, Armilla, Granada, Spain
| | - Marta Martínez-García
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Antonio Párraga-Leo
- Department of Organic and Pharmaceutical Chemistry, School of Pharmacy, University of Seville, Seville, Spain
| | - María Violante de Paz
- Department of Organic and Pharmaceutical Chemistry, School of Pharmacy, University of Seville, Seville, Spain
| | - Federico García
- Department of Clinical Microbiology, Instituto de Investigación Biosanitaria ibs. GRANADA, University Hospital Clínico San Cecilio, Granada, Spain
| | - Oscar P. Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands,Oscar P. Kuipers University of Groningen, Faculty of Science and Engineering, Department of Genetics, Nijenborgh 7, 9747AG, Groningen, The Netherlands
| | - Juan Carlos Morales
- Department of Biochemistry and Molecular Pharmacology, Instituto de Parasitología y Biomedicina López Neyra, CSIC, PTS Granada, Armilla, Granada, Spain,Juan Carlos Morales Instituto de Parasitología y Biomedicina López Neyra, CSIC, PTS Granada, Avda. del Conocimiento 17, Armilla, 18016Granada, Spain
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Lee Upton S, Tay JW, Schwartz DK, Sousa MC. Similarly slow diffusion of BAM and SecYEG complexes in live E. coli cells observed with 3D spt-PALM. Biophys J 2023; 122:4382-4394. [PMID: 37853695 PMCID: PMC10698321 DOI: 10.1016/j.bpj.2023.10.017] [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: 04/19/2023] [Revised: 09/05/2023] [Accepted: 10/16/2023] [Indexed: 10/20/2023] Open
Abstract
The β-barrel assembly machinery (BAM) complex is responsible for inserting outer membrane proteins (OMPs) into the Escherichia coli outer membrane. The SecYEG translocon inserts inner membrane proteins into the inner membrane and translocates both soluble proteins and nascent OMPs into the periplasm. Recent reports describe Sec possibly playing a direct role in OMP biogenesis through interactions with the soluble polypeptide transport-associated (POTRA) domains of BamA (the central OMP component of BAM). Here we probe the diffusion behavior of these protein complexes using photoactivatable super-resolution localization microscopy and single-particle tracking in live E. coli cells of BAM and SecYEG components BamA and SecE and compare them to other outer and inner membrane proteins. To accurately measure trajectories on the highly curved cell surface, three-dimensional tracking was performed using double-helix point-spread function microscopy. All proteins tested exhibit two diffusive modes characterized by "slow" and "fast" diffusion coefficients. We implement a diffusion coefficient analysis as a function of the measurement lag time to separate positional uncertainty from true mobility. The resulting true diffusion coefficients of the slow and fast modes showed a complete immobility of full-length BamA constructs in the time frame of the experiment, whereas the OMP OmpLA displayed a slow diffusion consistent with the high viscosity of the outer membrane. The periplasmic POTRA domains of BamA were found to anchor BAM to other cellular structures and render it immobile. However, deletion of individual distal POTRA domains resulted in increased mobility, suggesting that these domains are required for the full set of cellular interactions. SecE diffusion was much slower than that of the inner membrane protein PgpB and was more like OMPs and BamA. Strikingly, SecE diffused faster upon POTRA domain deletion. These results are consistent with the existence of a BAM-SecYEG trans-periplasmic assembly in live E. coli cells.
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Affiliation(s)
- Stephen Lee Upton
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado
| | - Jian Wei Tay
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado
| | - Daniel Keith Schwartz
- Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado
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Elshenawi Y, Hu S, Hathroubi S. Biofilm of Helicobacter pylori: Life Cycle, Features, and Treatment Options. Antibiotics (Basel) 2023; 12:1260. [PMID: 37627679 PMCID: PMC10451559 DOI: 10.3390/antibiotics12081260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/27/2023] Open
Abstract
Helicobacter pylori is a gastric pathogen that infects nearly half of the global population and is recognized as a group 1 carcinogen by the Word Health Organization. The global rise in antibiotic resistance has increased clinical challenges in treating H. pylori infections. Biofilm growth has been proposed to contribute to H. pylori's chronic colonization of the host stomach, treatment failures, and the eventual development of gastric diseases. Several components of H. pylori have been identified to promote biofilm growth, and several of these may also facilitate antibiotic tolerance, including the extracellular matrix, outer membrane proteins, shifted morphology, modulated metabolism, efflux pumps, and virulence factors. Recent developments in therapeutic approaches targeting H. pylori biofilm have shown that synthetic compounds, such as small molecule drugs and plant-derived compounds, are effective at eradicating H. pylori biofilms. These combined topics highlight the necessity for biofilm-based research in H. pylori, to improve current H. pylori-targeted therapeutic approaches and alleviate relative public health burden. In this review we discuss recent discoveries that have decoded the life cycle of H. pylori biofilms and current biofilm-targeted treatment strategies.
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Affiliation(s)
- Yasmine Elshenawi
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA;
| | - Shuai Hu
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, CA 95064, USA;
| | - Skander Hathroubi
- Spartha Medical, CRBS 1 Rue Eugène Boeckel, 67000 Strasbourg, France
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Usvaliev AD, Belogurova NG, Pokholok KV, Finko AV, Prusov AN, Golovin DY, Miroshnikov KA, Golovin YI, Klyachko NL. E. coli Cell Lysis Induced by Lys394 Enzyme Assisted by Magnetic Nanoparticles Exposed to Non-Heating Low-Frequency Magnetic Field. Pharmaceutics 2023; 15:1871. [PMID: 37514057 PMCID: PMC10384812 DOI: 10.3390/pharmaceutics15071871] [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: 05/11/2023] [Revised: 06/20/2023] [Accepted: 06/28/2023] [Indexed: 07/30/2023] Open
Abstract
The spreading of microbial pathogens with more and more resistance to traditional low-molecular antibiotic agents demands new approaches to antibacterial therapy. The employment of bacteriophage enzymes capable of breaking bacterial cell walls has attracted much interest within this context. The specific features of the morphology of Gram-negative bacteria prevent the effective direct usage of lytic enzymes and require assistance from additional helpers to facilitate cell lysis. The current work is devoted to the study of boosting the lysis of Escherichia coli (E. coli) JM 109 and MH 1 strains induced by Lys394 bacteriophage endolysin by means of rod-like (56 × 13 nm) magnetic nanoparticles (MNPs) activated by a non-heating low-frequency magnetic field (LF MF) with a frequency of 50 Hz and a flux density of 68.5 mT in a pulse-pause mode (1 s on and 0.3 s off). According to theoretical assumptions, the mechanism of MNP assistance is presumably based upon the disordering of the outer membrane that facilitates enzyme permeation into peptidoglycans to its substrate. It is found that the effect of the LF MF reaches an almost a twofold acceleration of the enzyme reaction, resulting in almost 80 and 70%, respectively, of lysed E. coli JM 109 and MH 1 cells in 21 min. An increase in the membrane permeability was proven by two independent experiments employing β-lactamase periplasmic enzyme leakage and Nile Red (NR) hydrophobic dye fluorescence. It is shown that the outer membrane disordering of E. coli caused by exposure to LF MF nanoparticle movement leads to almost complete (more than 80%) β-lactamase release out of the cells' periplasm to the buffer suspension. Experiments with NR (displaying fluorescence in a non-polar medium only) reveal a drastic reduction in NR fluorescence intensity, reaching a change of an order of magnitude when exposed to LF MF. The data obtained provide evidence of changes in the bacterial cell wall structure. The result shown open up the prospects of non-heating LF MF application in enhancing enzyme activity against Gram-negative pathogens.
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Affiliation(s)
- Azizbek D Usvaliev
- School of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
- Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | | | | | - Alexander V Finko
- School of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Andrey N Prusov
- A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia
| | - Dmitry Yu Golovin
- Institute of Nanomaterials and Nanotechnologies, G.R. Derzhavin Tambov State University, Tambov 392000, Russia
| | - Konstantin A Miroshnikov
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
| | - Yuri I Golovin
- School of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
- Institute of Nanomaterials and Nanotechnologies, G.R. Derzhavin Tambov State University, Tambov 392000, Russia
| | - Natalia L Klyachko
- School of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
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Ahmed AAQ, Besio R, Xiao L, Forlino A. Outer Membrane Vesicles (OMVs) as Biomedical Tools and Their Relevance as Immune-Modulating Agents against H. pylori Infections: Current Status and Future Prospects. Int J Mol Sci 2023; 24:ijms24108542. [PMID: 37239888 DOI: 10.3390/ijms24108542] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/26/2023] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
Outer membrane vesicles (OMVs) are lipid-membrane-bounded nanoparticles that are released from Gram-negative bacteria via vesiculation of the outer membrane. They have vital roles in different biological processes and recently, they have received increasing attention as possible candidates for a broad variety of biomedical applications. In particular, OMVs have several characteristics that enable them to be promising candidates for immune modulation against pathogens, such as their ability to induce the host immune responses given their resemblance to the parental bacterial cell. Helicobacter pylori (H. pylori) is a common Gram-negative bacterium that infects half of the world's population and causes several gastrointestinal diseases such as peptic ulcer, gastritis, gastric lymphoma, and gastric carcinoma. The current H. pylori treatment/prevention regimens are poorly effective and have limited success. This review explores the current status and future prospects of OMVs in biomedicine with a special focus on their use as a potential candidate in immune modulation against H. pylori and its associated diseases. The emerging strategies that can be used to design OMVs as viable immunogenic candidates are discussed.
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Affiliation(s)
- Abeer Ahmed Qaed Ahmed
- Department of Molecular Medicine, Biochemistry Unit, University of Pavia, 27100 Pavia, Italy
| | - Roberta Besio
- Department of Molecular Medicine, Biochemistry Unit, University of Pavia, 27100 Pavia, Italy
| | - Lin Xiao
- School of Biomedical Engineering, Shenzhen Campus, Sun Yat-sen University, Shenzhen 518107, China
| | - Antonella Forlino
- Department of Molecular Medicine, Biochemistry Unit, University of Pavia, 27100 Pavia, Italy
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12
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Cui ZH, He HL, Zheng ZJ, Yuan ZQ, Chen Y, Huang XY, Ren H, Zhou YF, Zhao DH, Fang LX, Yu Y, Liu YH, Liao XP, Sun J. Phentolamine Significantly Enhances Macrolide Antibiotic Antibacterial Activity against MDR Gram-Negative Bacteria. Antibiotics (Basel) 2023; 12:antibiotics12040760. [PMID: 37107122 PMCID: PMC10135019 DOI: 10.3390/antibiotics12040760] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/10/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
OBJECTIVES Multidrug-resistant (MDR) Gram-negative bacterial infections have limited treatment options due to the impermeability of the outer membrane. New therapeutic strategies or agents are urgently needed, and combination therapies using existing antibiotics are a potentially effective means to treat these infections. In this study, we examined whether phentolamine can enhance the antibacterial activity of macrolide antibiotics against Gram-negative bacteria and investigated its mechanism of action. METHODS Synergistic effects between phentolamine and macrolide antibiotics were evaluated by checkerboard and time-kill assays and in vivo using a Galleria mellonella infection model. We utilized a combination of biochemical tests (outer membrane permeability, ATP synthesis, ΔpH gradient measurements, and EtBr accumulation assays) with scanning electron microscopy to clarify the mechanism of phentolamine enhancement of macrolide antibacterial activity against Escherichia coli. RESULTS In vitro tests of phentolamine combined with the macrolide antibiotics erythromycin, clarithromycin, and azithromycin indicated a synergistic action against E. coli test strains. The fractional concentration inhibitory indices (FICI) of 0.375 and 0.5 indicated a synergic effect that was consistent with kinetic time-kill assays. This synergy was also seen for Salmonella typhimurium, Klebsiella pneumoniae, and Actinobacter baumannii but not Pseudomonas aeruginosa. Similarly, a phentolamine/erythromycin combination displayed significant synergistic effects in vivo in the G. mellonella model. Phentolamine added singly to bacterial cells also resulted in direct outer membrane damage and was able to dissipate and uncouple membrane proton motive force from ATP synthesis that, resulted in enhanced cytoplasmic antibiotic accumulation via reduced efflux pump activity. CONCLUSIONS Phentolamine potentiates macrolide antibiotic activity via reducing efflux pump activity and direct damage to the outer membrane leaflet of Gram-negative bacteria both in vitro and in vivo.
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Affiliation(s)
- Ze-Hua Cui
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Hui-Ling He
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Zi-Jian Zheng
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Zhao-Qi Yuan
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Ying Chen
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Xin-Yi Huang
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Hao Ren
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Yu-Feng Zhou
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Dong-Hao Zhao
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Liang-Xing Fang
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Yang Yu
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Ya-Hong Liu
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
- Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Xiao-Ping Liao
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
| | - Jian Sun
- Guangdong Laboratory for Lingnan Modern Agriculture, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics, Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China
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13
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Ding T, Zhang L, Han J, Zhou J, Han Y. Photo-Responded Antibacterial Therapy of Reinfection in Percutaneous Implants by Nanostructured Bio-Heterojunction. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206265. [PMID: 36470672 DOI: 10.1002/smll.202206265] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/08/2022] [Indexed: 06/17/2023]
Abstract
Percutaneous implants may experience infection for several times during their servicing periods. They need antibacterial activity and durability to reduce recurrent infection and cytocompatibility to reconstruct biosealing. A novel photoresponse bio-heterojunction (PCT) is developed herein. It consists of TiO2 nanotubes loaded with CuS nanoparticles and wrapped with polydopamine (PDA) layer. In PCT, a built-in electric field directing from TiO2 to CuS and then to PDA is formed, and with near-infrared (NIR) irradiation, it drives photoexcited electrons to transfer in opposite direction, resulting in the separation of electron-hole pairs and formation of reactive oxygen species (ROS). Simultaneously, PCT shows photothermal effect due to nonradiative relaxation of photoexcited electrons and thermal vibration of lattices. The synergic effect of photogenerated ROS and hyperthermia increases bacterial membrane permeability and leakage of cellular components, endowing PCT with outstanding antibacterial performance. More importantly, PCT has good antibacterial durability and cytocompatibility due to the inhibited leaching of CuS by PDA layer. In reinfected models, with NIR irradiation, PCT sterilizes bacteria, reduces inflammatory response and enhances re-integration of soft tissue efficiently. This work provides an outstanding bio-heterojunction for percutaneous implants in treating reinfection by NIR irradiation and rebuilding biosealing.
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Affiliation(s)
- Tiexin Ding
- State-key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
- State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083, P. R. China
| | - Lan Zhang
- State-key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
- State Key Laboratory of Powder Metallurgy, Central South University, Changsha, 410083, P. R. China
| | - Jing Han
- School of Public Health, Health Science Center, Xi'an Jiaotong University, Xi'an, 710061, P. R. China
| | - Jianhong Zhou
- Institute of Physics & Optoelectronics Technology, Advanced Titanium Alloys and Functional Coatings Cooperative Innovation Center, Baoji University of Arts and Sciences, Baoji, 721016, P. R. China
| | - Yong Han
- State-key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
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14
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Sheng Q, Zhang MY, Liu SM, Chen ZW, Yang PL, Zhang HS, Liu MY, Li K, Zhao LS, Liu NH, Liu LN, Chen XL, Hobbs JK, Foster SJ, Zhang YZ, Su HN. In situ visualization of Braun's lipoprotein on E. coli sacculi. SCIENCE ADVANCES 2023; 9:eadd8659. [PMID: 36662863 PMCID: PMC9858504 DOI: 10.1126/sciadv.add8659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
Braun's lipoprotein (Lpp) plays a major role in stabilizing the integrity of the cell envelope in Escherichia coli, as it provides a covalent cross-link between the outer membrane and the peptidoglycan layer. An important challenge in elucidating the physiological role of Lpp lies in attaining a detailed understanding of its distribution on the peptidoglycan layer. Here, using atomic force microscopy, we visualized Lpp directly on peptidoglycan sacculi. Lpp is homogeneously distributed over the outer surface of the sacculus at a high density. However, it is absent at the constriction site during cell division, revealing its role in the cell division process with Pal, another cell envelope-associated protein. Collectively, we have established a framework to elucidate the distribution of Lpp and other peptidoglycan-bound proteins via a direct imaging modality.
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Affiliation(s)
- Qi Sheng
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
- College of Marine Life Sciences and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China
| | - Meng-Yao Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Si-Min Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Zhuo-Wei Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Pei-Ling Yang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Hong-Su Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Meng-Yun Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Kang Li
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Long-Sheng Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Ning-Hua Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Lu-Ning Liu
- College of Marine Life Sciences and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Xiu-Lan Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Jamie K. Hobbs
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, UK
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK
| | - Simon J. Foster
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, UK
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Yu-Zhong Zhang
- College of Marine Life Sciences and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Hai-Nan Su
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
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15
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Abstract
This review focuses on nonlytic outer membrane vesicles (OMVs), a subtype of bacterial extracellular vesicles (BEVs) produced by Gram-negative organisms focusing on the mechanisms of their biogenesis, cargo, and function. Throughout, we highlight issues concerning the characterization of OMVs and distinguishing them from other types of BEVs. We also highlight the shortcomings of commonly used methodologies for the study of BEVs that impact the interpretation of their functionality and suggest solutions to standardize protocols for OMV studies.
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Affiliation(s)
| | - Simon R. Carding
- Quadram Institute Bioscience, Norwich, United Kingdom
- Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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16
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Guevara-Tique AA, Torres RC, Bravo MM, Carvajal Carmona LG, Echeverry de Polanco MM, Bohórquez ME, Torres J. Recombination events drives the emergence of Colombian Helicobacter pylori subpopulations with self-identity ancestry. Virulence 2022; 13:1146-1160. [PMID: 35838227 PMCID: PMC9291697 DOI: 10.1080/21505594.2022.2095737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Helicobacter pylori have coevolved with mankind since its origins, adapting to different human groups. In America, H. pylori has evolved into several subpopulations. We analysed the genome of 154 Colombian strains along with 1,091 strains from worldwide populations to discern the ancestry and adaption to Colombian people. Population structure and ancestry was inferred with FineStructure and ChromoPainter. Phylogenetic relationship and the relative effect of recombination were analysing the core SNPs. Also, a Fst index was calculated to identify the gene variants with the strongest fixation in the Colombian subpopulations compared to their parent population hspSWEurope. FineStructure allowed the identification of two Colombian subpopulations, the previously described hspSWEuropeColombia and a novel subpopulation named hspColombia, that included three subgroups following their geographic origin. Colombian subpopulations represent an admixture of European, African and Indigenous ancestry; although some genomes showed a high proportion of self identity, suggesting an advanced adaption to these mestizo Colombian groups. We found that recombination is more important that punctual mutations in H. pylori genome diversity, 13.9 more important in hspSWEurope, 12.5 in hspSWEColombia and 10.5 in hspColombia, reflecting the divergence of these subpopulations. Fst analysis identified 82 SNPs fixed in 26 genes of the hspColombia subpopulation that encode for outer membrane and central metabolism proteins. Strongest fixation indexes were identified in genes encoding HofC, HopE, FrpB-4 and Sialidase A. These findings demonstrate that H. pylori has evolved in Colombia to give rise to subpopulations with a self identity ancestry, reflected in allele changes on genes encoding for outer membrane proteins.
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Affiliation(s)
- Alix A Guevara-Tique
- Grupo de Investigación en Citogenética, Filogenia y Evolución de Poblaciones, Departamento de Ciencias y Ciencias de la Salud, Universidad del Tolima, Tolima, Colombia
| | - Roberto C Torres
- The Center for Microbes, Development and Health, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Maria M Bravo
- Laboratorio de Inmunología, Instituto Nacional de Cancerología, Bogotá, D. C., Colombia
| | - Luis G Carvajal Carmona
- Genome Center, Department of Biochemistry and Molecular Medicine, School of Medicine-University of California, Davis, California, USA
| | - María M Echeverry de Polanco
- Grupo de Investigación en Citogenética, Filogenia y Evolución de Poblaciones, Departamento de Ciencias y Ciencias de la Salud, Universidad del Tolima, Tolima, Colombia
| | - Mabel E Bohórquez
- Grupo de Investigación en Citogenética, Filogenia y Evolución de Poblaciones, Departamento de Ciencias y Ciencias de la Salud, Universidad del Tolima, Tolima, Colombia.,Medicine Program, Department of Health Sciences, Tolima University, Tolima, Colombia
| | - Javier Torres
- c Unidad de Investigación en Enfermedades Infecciosas, UMAE Pediatria, Instituto Mexicano del Seguro Social, México
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17
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Fontelo R, Soares da Costa D, Gomez-Florit M, Tiainen H, Reis RL, Novoa-Carballal R, Pashkuleva I. Antibacterial nanopatterned coatings for dental implants. J Mater Chem B 2022; 10:8710-8718. [PMID: 36214372 DOI: 10.1039/d2tb01352e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Dental implants, usually made of titanium, are exposed to hostile oral microflora that facilitate bacterial infections and subsequent inflammation. To mitigate these processes, we coated titanium substrates with block copolymer nanopatterns and investigated the bactericidal effect of these coatings against Gram-positive and Gram-negative bacteria. We found that the bactericidal efficacy of the coatings depends on their morphology and surface chemistry as well as on the bacterial strain: an optimal combination can lead to significant bacterial death for a short time, i.e. 90% for 90 min. Human gingival fibroblasts in contact with the nanopatterned coatings showed similar cell attachment and morphology as on bare Ti. Immunostaining assays showed similar levels of CCR7 and CD206 in macrophages cultured over the nanopatterns and bare Ti, demonstrating adequate properties for tissue integration. The nanopatterns induced a small increase in macrophage aspect ratio, which might indicate early states of M2 polarization, given the absence of CD206.
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Affiliation(s)
- Raul Fontelo
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco, Portugal. .,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Diana Soares da Costa
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco, Portugal. .,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Manuel Gomez-Florit
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco, Portugal. .,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Hanna Tiainen
- Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, P.O. Box 1109, Blindern, Oslo 0317, Norway
| | - Rui L Reis
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco, Portugal. .,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Ramon Novoa-Carballal
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco, Portugal. .,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Iva Pashkuleva
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco, Portugal. .,ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
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18
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Novel Type of Tetranitrosyl Iron Salt: Synthesis, Structure and Antibacterial Activity of Complex [FeL' 2(NO) 2][FeL'L"(NO) 2] with L'-thiobenzamide and L"-thiosulfate. Molecules 2022; 27:molecules27206886. [PMID: 36296478 PMCID: PMC9611265 DOI: 10.3390/molecules27206886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/08/2022] [Accepted: 10/11/2022] [Indexed: 11/05/2022] Open
Abstract
In this work a new donor of nitric oxide (NO) with antibacterial properties, namely nitrosyl iron complex of [Fe(C6H5C-SNH2)2(NO)2][Fe(C6H5C-SNH2)(S2O3)(NO)2] composition (complex I), has been synthesized and studied. Complex I was produced by the reduction of the aqueous solution of [Fe2(S2O3)2(NO)2]2− dianion by the thiosulfate, with the further treatment of the mixture by the acidified alcohol solution of thiobenzamide. Based on the structural study of I (X-ray analysis, quantum chemical calculations by NBO and QTAIM methods in the frame of DFT), the data were obtained on the presence of the NO…NO interactions, which stabilize the DNIC dimer in the solid phase. The conformation properties, electronic structure and free energies of complex I hydration were studied using B3LYP functional and the set of 6–31 + G(d,p) basis functions. The effect of an aquatic surrounding was taken into account in the frame of a polarized continuous model (PCM). The NO-donating activity of complex I was studied by the amperometry method using an “amiNO-700” sensor electrode of the “inNO Nitric Oxide Measuring System”. The antibacterial activity of I was studied on gram-negative (Escherichia coli) and gram-positive (Micrococcus luteus) bacteria. Cytotoxicity was studied using Vero cells. Complex I was found to exhibit antibacterial activity comparable to that of antibiotics, and moderate toxicity to Vero cells.
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19
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Park S, Cho H. The Tol-Pal System Plays an Important Role in Maintaining Cell Integrity During Elongation in Escherichia coli. Front Microbiol 2022; 13:891926. [PMID: 35592005 PMCID: PMC9111525 DOI: 10.3389/fmicb.2022.891926] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/07/2022] [Indexed: 11/13/2022] Open
Abstract
The Tol-Pal system is a transenvelope complex widely conserved among Gram-negative bacteria. It is recruited to the septal ring during cytokinesis, and its inactivation causes pleiotropic phenotypes mainly associated with the division process. From our genetic screen to identify factors required for delaying lysis upon treatment of beta lactams, we discovered that the tol-pal mutant shares similar defects with mutants of the major class A PBP system (PBP1b-LpoB) in terms of lysis prevention. Further phenotypic analyses revealed that the Tol-Pal system plays an important role in maintaining cell integrity not only during septation, but also during cell elongation. Simultaneous inactivation of the Tol-Pal system and the PBP1b-LpoB system leads to lysis during cell elongation as well as during division. Moreover, production of the Lpo activator-bypass PBP1b, but not wild-type PBP1b, partially suppressed the Tol-Pal defect in maintaining cell integrity upon treatment of mecillinam specific for the Rod system, suggesting that the Tol-Pal system is likely to be involved in the activation of aPBP by Lpo factors. Overall, our results indicate that the Tol-Pal system plays an important role in maintaining cell wall integrity during elongation in addition to its multifaceted roles during cytokinesis.
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Affiliation(s)
- Sohee Park
- Department of Biological Sciences, College of Natural Sciences, Sungkyunkwan University, Suwon, South Korea
| | - Hongbaek Cho
- Department of Biological Sciences, College of Natural Sciences, Sungkyunkwan University, Suwon, South Korea
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20
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Fang M, Xue Z, He L, You Y, Gong Y, Fan D, Sun L, Zhai K, Yang Y, Zhang J. Distribution characteristics of the sabA, hofC, homA, homB and frpB-4 genes of Helicobacter pylori in different regions of China. PLoS One 2022; 17:e0268373. [PMID: 35588168 PMCID: PMC9119684 DOI: 10.1371/journal.pone.0268373] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 04/28/2022] [Indexed: 11/18/2022] Open
Abstract
Background Helicobacter pylori (H. pylori) encodes numerous outer membrane proteins (OMPs), with considerable geographic heterogeneity and related to different clinical outcomes. This study aimed to investigate the distribution characteristics of five important OMP genes (sabA, hofC, homA, homB and frpB-4) in different regions of China. Materials and method A total of 266 strains were isolated from 348 stomach biopsy specimens in Shandong, Guangxi, Heilongjiang, Hunan, and Qinghai provinces. The presence of sabA, hofC, homA, homB and frpB-4 gene was detected by polymerase chain reaction (PCR) from H. pylori genomic DNA. Results Among the strains in five regions, the prevalence of frpB-4 was 100% and that of hofC was 97.7%. The prevalence of homB in the isolates from Qinghai (45.5%) was significantly lower than that in Shandong (75.3%), Guangxi (76.9%) and Hunan (69.6%) (P<0.05). The frequency of homA in Shandong (30.1%) was significantly lower than in Guangxi (57.7%) and Qinghai (63.6%) (P<0.05). The prevalence of the sabA gene in Shandong, Guangxi, Heilongjiang, Hunan and Qinghai provinces was 21.9%, 59.7%, 45.9%, 52.2%, and 18.2%, respectively (P<0.05). The sabA “on” status was significantly more frequent in isolates from Guangxi (46.8%), Heilongjiang (37.8%), and Hunan (47.8%) than Qinghai (3.0%) (P<0.05). The presence of homA and sabA genes may be negatively correlated with the development of gastritis. There was no significant association between the frpB-4, hofC, homB gene and clinical outcomes. Conclusion The prevalence of homA, homB, and sabA genes and the sabA “on” or “off” status have significant geographical differences among five provinces in China. The presence of homA and sabA genes may be protective factors of gastritis.
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Affiliation(s)
- Mengyang Fang
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Zhijing Xue
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Lihua He
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Yuanhai You
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Yanan Gong
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Dongjie Fan
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Lu Sun
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Kangle Zhai
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Yaming Yang
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
| | - Jianzhong Zhang
- Department of Epidemiology, School of Public Health, Nanjing Medical University, Nanjing, China
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Beijing, China
- * E-mail:
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21
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An ancient divide in outer membrane tethering systems in bacteria suggests a mechanism for the diderm-to-monoderm transition. Nat Microbiol 2022; 7:411-422. [PMID: 35246664 DOI: 10.1038/s41564-022-01066-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 01/24/2022] [Indexed: 11/08/2022]
Abstract
Recent data support the hypothesis that Gram-positive bacteria (monoderms) arose from Gram-negative ones (diderms) through loss of the outer membrane (OM), but how this happened remains unknown. As tethering of the OM is essential for cell envelope stability in diderm bacteria, its destabilization may have been involved in this transition. In the present study, we present an in-depth analysis of the four known main OM-tethering systems across the Tree of Bacteria (ToB). We show that the presence of such systems follows the ToB with a bimodal distribution matching the deepest phylogenetic divergence between Terrabacteria and Gracilicutes. Whereas the lipoprotein peptidoglycan-associated lipoprotein (Pal) is restricted to the Gracilicutes, along with a more sporadic occurrence of OmpA, and Braun's lipoprotein is present only in a subclade of Gammaproteobacteria, diderm Terrabacteria display, as the main system, the OmpM protein. We propose an evolutionary scenario whereby OmpM represents a simple, ancestral OM-tethering system that was later replaced by one based on Pal after the emergence of the Lol machinery to deliver lipoproteins to the OM, with OmpA as a possible transition state. We speculate that the existence of only one main OM-tethering system in the Terrabacteria would have allowed the multiple OM losses specifically inferred in this clade through OmpM perturbation, and we provide experimental support for this hypothesis by inactivating all four ompM gene copies in the genetically tractable diderm Firmicute Veillonella parvula. High-resolution imaging and tomogram reconstructions reveal a non-lethal phenotype in which vast portions of the OM detach from the cells, forming huge vesicles with an inflated periplasm shared by multiple dividing cells. Together, our results highlight an ancient shift of OM-tethering systems in bacterial evolution and suggest a mechanism for OM loss and the multiple emergences of the monoderm phenotype from diderm ancestors.
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22
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Webby MN, Williams-Jones DP, Press C, Kleanthous C. Force-Generation by the Trans-Envelope Tol-Pal System. Front Microbiol 2022; 13:852176. [PMID: 35308353 PMCID: PMC8928145 DOI: 10.3389/fmicb.2022.852176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 01/26/2022] [Indexed: 11/13/2022] Open
Abstract
The Tol-Pal system spans the cell envelope of Gram-negative bacteria, transducing the potential energy of the proton motive force (PMF) into dissociation of the TolB-Pal complex at the outer membrane (OM), freeing the lipoprotein Pal to bind the cell wall. The primary physiological role of Tol-Pal is to maintain OM integrity during cell division through accumulation of Pal molecules at division septa. How the protein complex couples the PMF at the inner membrane into work at the OM is unknown. The effectiveness of this trans-envelope energy transduction system is underscored by the fact that bacteriocins and bacteriophages co-opt Tol-Pal as part of their import/infection mechanisms. Mechanistic understanding of this process has been hindered by a lack of structural data for the inner membrane TolQ-TolR stator, of its complexes with peptidoglycan (PG) and TolA, and of how these elements combined power events at the OM. Recent studies on the homologous stators of Ton and Mot provide a starting point for understanding how Tol-Pal works. Here, we combine ab initio protein modeling with previous structural data on sub-complexes of Tol-Pal as well as mutagenesis, crosslinking, co-conservation analysis and functional data. Through this composite pooling of in silico, in vitro, and in vivo data, we propose a mechanism for force generation in which PMF-driven rotary motion within the stator drives conformational transitions within a long TolA helical hairpin domain, enabling it to reach the TolB-Pal complex at the OM.
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Affiliation(s)
| | | | | | - Colin Kleanthous
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
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23
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BACCELLI P, RACHEDI R, SERRANO B, PETITI M, BERNARD C, HOUOT L, DUCHE D. Timing of TolA and TolQ recruitment at the septum depends on the functionality of the Tol-Pal system. J Mol Biol 2022; 434:167519. [DOI: 10.1016/j.jmb.2022.167519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 02/11/2022] [Accepted: 02/24/2022] [Indexed: 10/19/2022]
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Connolley L, Szczepaniak J, Kleanthous C, Murray SM. The quantitative basis for the redistribution of immobile bacterial lipoproteins to division septa. PLoS Comput Biol 2021; 17:e1009756. [PMID: 34965245 PMCID: PMC8751993 DOI: 10.1371/journal.pcbi.1009756] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 01/11/2022] [Accepted: 12/14/2021] [Indexed: 11/28/2022] Open
Abstract
The spatial localisation of proteins is critical for most cellular function. In bacteria, this is typically achieved through capture by established landmark proteins. However, this requires that the protein is diffusive on the appropriate timescale. It is therefore unknown how the localisation of effectively immobile proteins is achieved. Here, we investigate the localisation to the division site of the slowly diffusing lipoprotein Pal, which anchors the outer membrane to the cell wall of Gram-negative bacteria. While the proton motive force-linked TolQRAB system is known to be required for this repositioning, the underlying mechanism is unresolved, especially given the very low mobility of Pal. We present a quantitative, mathematical model for Pal relocalisation in which dissociation of TolB-Pal complexes, powered by the proton motive force across the inner membrane, leads to the net transport of Pal along the outer membrane and its deposition at the division septum. We fit the model to experimental measurements of protein mobility and successfully test its predictions experimentally against mutant phenotypes. Our model not only explains a key aspect of cell division in Gram-negative bacteria, but also presents a physical mechanism for the transport of low-mobility proteins that may be applicable to multi-membrane organelles, such as mitochondria and chloroplasts. In order for bacteria to successfully survive it is vital that they are able to concentrate proteins at precise sub-cellular locations. This usually occurs by capturing a freely diffusive protein, with the requirement that the protein is sufficiently mobile to reach the target location within the appropriate timeframe. Currently, it is unclear how immobile proteins are localised. Here, we examine how a very slowly diffusing protein Pal is able to localise to the centre of dividing cells to fulfil its role in membrane constriction. We present a mathematical model in which Pal is made mobile through the binding of another protein, TolB, and then deposited at the septum via active dissociation. This method is similar to a conveyor belt where Pal is collected everywhere but only deposited at the centre of the cell. We are able to fit this model to measurements of protein mobility and also test its predictions against mutant phenotypes. Our study is not only able to explain how this key protein is relocalised but also presents a general mechanism for the transport of slowly diffusing proteins that may be applicable to other systems.
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Affiliation(s)
- Lara Connolley
- Max Planck Institute for Terrestrial Microbiology and LOEWE Centre for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Joanna Szczepaniak
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Colin Kleanthous
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- * E-mail: (CK); (SMM)
| | - Seán M. Murray
- Max Planck Institute for Terrestrial Microbiology and LOEWE Centre for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
- * E-mail: (CK); (SMM)
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Belikov SI, Petrushin IS, Chernogor LI. Genome Analysis of the Janthinobacterium sp. Strain SLB01 from the Diseased Sponge of the Lubomirskia baicalensis. Curr Issues Mol Biol 2021; 43:2220-2237. [PMID: 34940130 PMCID: PMC8929069 DOI: 10.3390/cimb43030156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 12/22/2022] Open
Abstract
The strain Janthinobacterium sp. SLB01 was isolated from the diseased freshwater sponge Lubomirskia baicalensis (Pallas, 1776) and the draft genome was published previously. The aim of this work is to analyze the genome of the Janthinobacterium sp. SLB01 to search for pathogenicity factors for Baikal sponges. We performed genomic analysis to determine virulence factors, comparing the genome of the strain SLB01 with genomes of other related J. lividum strains from the environment. The strain Janthinobacterium sp. SLB01 contained genes encoding violacein, alpha-amylases, phospholipases, chitinases, collagenases, hemolysin, and a type VI secretion system. In addition, the presence of conservative clusters of genes for the biosynthesis of secondary metabolites of tropodithietic acid and marinocine was found. We present genes for antibiotic resistance, including five genes encoding various lactamases and eight genes for penicillin-binding proteins, which are conserved in all analyzed strains. Major differences were found between the Janthinobacterium sp. SLB01 and J. lividum strains in the spectra of genes for glycosyltransferases and glycoside hydrolases, serine hydrolases, and trypsin-like peptidase, as well as some TonB-dependent siderophore receptors. Thus, the study of the analysis of the genome of the strain SLB01 allows us to conclude that the strain may be one of the pathogens of freshwater sponges.
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Recruitment of the TolA protein to cell constriction sites in Escherichia coli via three separate mechanisms, and a critical role for FtsWI activity in recruitment of both TolA and TolQ. J Bacteriol 2021; 204:e0046421. [PMID: 34748387 DOI: 10.1128/jb.00464-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The Tol-Pal system of Gram-negative bacteria helps maintain integrity of the cell envelope and ensures that invagination of the envelope layers during cell fission occurs in a well-coordinated manner. In E. coli, the five Tol-Pal proteins (TolQ, R, A, B and Pal) accumulate at cell constriction sites in a manner that normally requires the activity of the cell constriction initiation protein FtsN. While septal recruitment of TolR, TolB and Pal also requires the presence of TolQ and/or TolA, each of the the latter two can recognize constriction sites independently of the other system proteins. What attracts TolQ or TolA to these sites is unclear. We show that FtsN attracts both proteins in an indirect fashion, and that PBP1A, PBP1B and CpoB are dispensable for their septal recruitment. However, the β-lactam aztreonam readily interferes with septal accumulation of both TolQ and TolA, indicating that FtsN-stimulated production of septal peptidoglycan by the FtsWI synthase is critical to their recruitment. We also discovered that each of TolA's three domains can recognize division sites in a separate fashion. Notably, the middle domain (TolAII) is responsible for directing TolA to constriction sites in the absence of other Tol-Pal proteins and CpoB, while recruitment of TolAI and TolAIII requires TolQ and a combination of TolB, Pal, and CpoB, respectively. Additionally, we describe the construction and use of functional fluorescent sandwich fusions of the ZipA division protein, which should be more broadly valuable in future studies of the E. coli cell division machinery. IMPORTANCE Cell division (cytokinesis) is a fundamental biological process that is incompletely understood for any organism. Division of bacterial cells relies on a ring-like machinery called the septal ring or divisome that assembles along the circumference of the mother cell at the site where constriction will eventually occur. In the well-studied bacterium Escherichia coli, this machinery contains over thirty distinct proteins. We studied how two such proteins, TolA and TolQ, which also play a role in maintaining integrity of the outer-membrane, are recruited to the machinery. We find that TolA can be recruited by three separate mechanisms, and that both proteins rely on the activity of a well-studied cell division enzyme for their recruitment.
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27
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Abstract
Colicins are protein antibiotics deployed by Escherichia coli to eliminate competing strains. Colicins frequently exploit outer membrane (OM) nutrient transporters to penetrate the selectively permeable bacterial cell envelope. Here, by applying live-cell fluorescence imaging, we were able to monitor the entry of the pore-forming toxin colicin B (ColB) into E. coli and localize it within the periplasm. We further demonstrate that single-stranded DNA coupled to ColB can also be transported to the periplasm, emphasizing that the import routes of colicins can be exploited to carry large cargo molecules into bacteria. Moreover, we characterize the molecular mechanism of ColB association with its OM receptor FepA by applying a combination of photoactivated cross-linking, mass spectrometry, and structural modeling. We demonstrate that complex formation is coincident with large-scale conformational changes in the colicin. Thereafter, active transport of ColB through FepA involves the colicin taking the place of the N-terminal half of the plug domain that normally occludes this iron transporter. IMPORTANCE Decades of excessive use of readily available antibiotics has generated a global problem of antibiotic resistance and, hence, an urgent need for novel antibiotic solutions. Bacteriocins are protein-based antibiotics produced by bacteria to eliminate closely related competing bacterial strains. Bacteriocin toxins have evolved to bypass the complex cell envelope in order to kill bacterial cells. Here, we uncover the cellular penetration mechanism of a well-known but poorly understood bacteriocin called colicin B that is active against Escherichia coli. Moreover, we demonstrate that the colicin B-import pathway can be exploited to deliver conjugated DNA cargo into bacterial cells. Our work leads to a better understanding of the way bacteriocins, as potential alternative antibiotics, execute their mode of action as well as highlighting how they might even be exploited in the genomic manipulation of Gram-negative bacteria.
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29
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Dayari AR, Asgari G, Seid-Mohammadi A, Samarghandi MR. Modified bone char with C-MgO as a green antibacterial household water treatment filter: Comparing the microbial quality with refrigerator cartridge filters. JOURNAL OF HAZARDOUS MATERIALS 2021; 414:125516. [PMID: 33667808 DOI: 10.1016/j.jhazmat.2021.125516] [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: 12/01/2020] [Revised: 01/27/2021] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
The present study examines the efficiency of modified bone char (BC) with C-MgO nanoparticles (MBC-C-MgO) as media in a cartridge filter as an antibacterial agent to produce a new filter. The filters were operated in a continuous mode using a pre-static pump. MBC-C-MgO were produced and modified with sucrose through the co-precipitation method. The microbial quality of effluent water samples was compared with commercial refrigerator cartridge filters using a heterotrophic plate count (HPC) test and SEM analysis. The results showed that the effluent water from the filter with MBC-C-MgO media had the lowest HPC (177 CFU/mL) compared to bioceramic (271 CFU/mL) and carbon (500 CFU/mL) under similar experimental conditions after 4 months of operation. Maximum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests were determined using the broth dilution method on Escherichia coli (ATCC 25922) and Enterococcus faecalis (ACC 29212). The MIC results for E. faecalis and E. coli were 156.25 and 312.5 µg/mL, respectively. Furthermore, the MBC results for E. faecalis and E. coli were 312.5 and 625 µg/mL. The experimental results obviously showed the antibacterial properties of C-MgO nanoparticles and the MBC-C-MgO.
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Affiliation(s)
- Ali Reza Dayari
- Social Determinants of Health Research Center (SDHRC), Department of Environmental Health Engineering, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Ghorban Asgari
- Social Determinants of Health Research Center (SDHRC), Department of Environmental Health Engineering, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Abdolmotaleb Seid-Mohammadi
- Social Determinants of Health Research Center (SDHRC), Department of Environmental Health Engineering, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mohammad Reza Samarghandi
- Department of Environmental Health Engineering, Faculty of Health and Research center for health sciences, Hamadan University of Medical Sciences, Hamadan, Iran
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Aliashkevich A, Cava F. LD-transpeptidases: the great unknown among the peptidoglycan cross-linkers. FEBS J 2021; 289:4718-4730. [PMID: 34109739 DOI: 10.1111/febs.16066] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 05/05/2021] [Accepted: 06/09/2021] [Indexed: 12/24/2022]
Abstract
The peptidoglycan (PG) cell wall is an essential polymer for the shape and viability of bacteria. Its protective role is in great part provided by its mesh-like character. Therefore, PG-cross-linking enzymes like the penicillin-binding proteins (PBPs) are among the best targets for antibiotics. However, while PBPs have been in the spotlight for more than 50 years, another class of PG-cross-linking enzymes called LD-transpeptidases (LDTs) seemed to contribute less to PG synthesis and, thus, has kept an aura of mystery. In the last years, a number of studies have associated LDTs with cell wall adaptation to stress including β-lactam antibiotics, outer membrane stability, and toxin delivery, which has shed light onto the biological meaning of these proteins. Furthermore, as some species display a great abundance of LD-cross-links in their cell wall, it has been hypothesized that LDTs could also be the main synthetic PG-transpeptidases in some bacteria. In this review, we introduce these enzymes and their role in PG biosynthesis and we highlight the most recent advances in understanding their biological role in diverse species.
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Affiliation(s)
- Alena Aliashkevich
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Umeå University, Sweden
| | - Felipe Cava
- Department of Molecular Biology and Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Umeå University, Sweden
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Wang J, Ansari MF, Zhou CH. Identification of Unique Quinazolone Thiazoles as Novel Structural Scaffolds for Potential Gram-Negative Bacterial Conquerors. J Med Chem 2021; 64:7630-7645. [PMID: 34009979 DOI: 10.1021/acs.jmedchem.1c00334] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A class of quinazolone thiazoles was identified as new structural scaffolds for potential antibacterial conquerors to tackle dreadful resistance. Some prepared compounds exhibited favorable bacteriostatic efficiencies on tested bacteria, and the most representative 5j featuring the 4-trifluoromethylphenyl group possessed superior performances against Escherichia coli and Pseudomonas aeruginosa to norfloxacin. Further studies revealed that 5j with inappreciable hemolysis could hinder the formation of bacterial biofilms and trigger reactive oxygen species generation, which could take responsibility for emerging low resistance. Subsequent paralleled exploration discovered that 5j not only disintegrated outer and inner membranes to induce leakage of cytoplasmic contents but also broke the metabolism by suppressing dehydrogenase. Meanwhile, derivative 5j could intercalate into DNA to exert powerful antibacterial properties. Moreover, compound 5j gave synergistic effects against some Gram-negative bacteria in combination with norfloxacin. These findings indicated that this novel structural type of quinazolone thiazoles showed therapeutic foreground in struggling with Gram-negative bacterial infections.
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Affiliation(s)
- Jie Wang
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
| | - Mohammad Fawad Ansari
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
| | - Cheng-He Zhou
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
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Machas M, Kurgan G, Abed OA, Shapiro A, Wang X, Nielsen D. Characterizing Escherichia coli's transcriptional response to different styrene exposure modes reveals novel toxicity and tolerance insights. J Ind Microbiol Biotechnol 2021; 48:kuab019. [PMID: 33640981 PMCID: PMC9138201 DOI: 10.1093/jimb/kuab019] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/18/2021] [Indexed: 11/24/2022]
Abstract
The global transcriptional response of Escherichia coli to styrene and potential influence of exposure source was determined by performing RNA sequencing (RNA-seq) analysis on both styrene-producing and styrene-exposed cells. In both cases, styrene exposure appears to cause both cell envelope and DNA damage, to which cells respond by down-regulating key genes/pathways involved in DNA replication, protein production, and cell wall biogenesis. Among the most significantly up-regulated genes were those involved with phage shock protein response (e.g. pspABCDE/G), general stress regulators (e.g. marA, rpoH), and membrane-altering genes (notably, bhsA, ompR, ldtC), whereas efflux transporters were, surprisingly, unaffected. Subsequent studies with styrene addition demonstrate how strains lacking ompR [involved in controlling outer membrane (OM) composition/osmoregulation] or any of tolQ, tolA, or tolR (involved in OM constriction) each displayed over 40% reduced growth relative to wild-type. Conversely, despite reducing basal fitness, overexpression of plsX (involved in phospholipid biosynthesis) led to 70% greater growth when styrene exposed. These collective differences point to the likely importance of OM properties in controlling native styrene tolerance. Overall, the collective behaviours suggest that, regardless of source, prolonged exposure to inhibitory styrene levels causes cells to shift from'growth mode' to 'survival mode', redistributing cellular resources to fuel native tolerance mechanisms.
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Affiliation(s)
- Michael Machas
- Chemical Engineering, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ 85287-6106, USA
| | - Gavin Kurgan
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-6106, USA
| | - Omar A Abed
- Chemical Engineering, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ 85287-6106, USA
| | - Alyssa Shapiro
- Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Xuan Wang
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-6106, USA
| | - David Nielsen
- Chemical Engineering, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ 85287-6106, USA
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Blaschke U, Skiebe E, Wilharm G. Novel Genes Required for Surface-Associated Motility in Acinetobacter baumannii. Curr Microbiol 2021; 78:1509-1528. [PMID: 33666749 PMCID: PMC7997844 DOI: 10.1007/s00284-021-02407-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 02/10/2021] [Indexed: 01/28/2023]
Abstract
Acinetobacter baumannii is an opportunistic and increasingly multi-drug resistant human pathogen rated as a critical priority one pathogen for the development of new antibiotics by the WHO in 2017. Despite the lack of flagella, A. baumannii can move along wet surfaces in two different ways: via twitching motility and surface-associated motility. While twitching motility is known to depend on type IV pili, the mechanism of surface-associated motility is poorly understood. In this study, we established a library of 30 A. baumannii ATCC® 17978™ mutants that displayed deficiency in surface-associated motility. By making use of natural competence, we also introduced these mutations into strain 29D2 to differentiate strain-specific versus species-specific effects of mutations. Mutated genes were associated with purine/pyrimidine/folate biosynthesis (e.g. purH, purF, purM, purE), alarmone/stress metabolism (e.g. Ap4A hydrolase), RNA modification/regulation (e.g. methionyl-tRNA synthetase), outer membrane proteins (e.g. ompA), and genes involved in natural competence (comEC). All tested mutants originally identified as motility-deficient in strain ATCC® 17978™ also displayed a motility-deficient phenotype in 29D2. By contrast, further comparative characterization of the mutant sets of both strains regarding pellicle biofilm formation, antibiotic resistance, and virulence in the Galleria mellonella infection model revealed numerous strain-specific mutant phenotypes. Our studies highlight the need for comparative analyses to characterize gene functions in A. baumannii and for further studies on the mechanisms underlying surface-associated motility.
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Affiliation(s)
- Ulrike Blaschke
- Robert Koch Institute, Project group P2, Burgstr. 37, 38855, Wernigerode, Germany.
| | - Evelyn Skiebe
- Robert Koch Institute, Project group P2, Burgstr. 37, 38855, Wernigerode, Germany
| | - Gottfried Wilharm
- Robert Koch Institute, Project group P2, Burgstr. 37, 38855, Wernigerode, Germany.
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34
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Sears KT, Galen JE, Tennant SM. Advances in the development of Salmonella-based vaccine strategies for protection against Salmonellosis in humans. J Appl Microbiol 2021; 131:2640-2658. [PMID: 33665941 PMCID: PMC9292744 DOI: 10.1111/jam.15055] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/18/2021] [Accepted: 03/02/2021] [Indexed: 11/29/2022]
Abstract
Salmonella spp. are important human pathogens globally causing millions of cases of typhoid fever and non‐typhoidal salmonellosis annually. There are only a few vaccines licensed for use in humans which all target Salmonella enterica serovar Typhi. Vaccine development is hampered by antigenic diversity between the thousands of serovars capable of causing infection in humans. However, a number of attenuated candidate vaccine strains are currently being developed. As facultative intracellular pathogens with multiple systems for transporting effector proteins to host cells, attenuated Salmonella strains can also serve as ideal tools for the delivery of foreign antigens to create multivalent live carrier vaccines for simultaneous immunization against several unrelated pathogens. Further, the ease with which Salmonella can be genetically modified and the extensive knowledge of the virulence mechanisms of this pathogen means that this bacterium has often served as a model organism to test new approaches. In this review we focus on (1) recent advances in live attenuated Salmonella vaccine development, (2) improvements in expression of foreign antigens in carrier vaccines and (3) adaptation of attenuated strains as sources of purified antigens and vesicles that can be used for subunit and conjugate vaccines or together with attenuated vaccine strains in heterologous prime‐boosting immunization strategies. These advances have led to the development of new vaccines against Salmonella which have or will soon be tested in clinical trials.
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Affiliation(s)
- K T Sears
- Center for Vaccine Development and Global Health, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - J E Galen
- Center for Vaccine Development and Global Health, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - S M Tennant
- Center for Vaccine Development and Global Health, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
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35
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Szczepaniak J, Press C, Kleanthous C. The multifarious roles of Tol-Pal in Gram-negative bacteria. FEMS Microbiol Rev 2021; 44:490-506. [PMID: 32472934 PMCID: PMC7391070 DOI: 10.1093/femsre/fuaa018] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 05/28/2020] [Indexed: 12/15/2022] Open
Abstract
In the 1960s several groups reported the isolation and preliminary genetic mapping of
Escherichia coli strains tolerant towards the
action of colicins. These pioneering studies kick-started two new fields in bacteriology;
one centred on how bacteriocins like colicins exploit the Tol (or more commonly Tol-Pal)
system to kill bacteria, the other on the physiological role of this cell
envelope-spanning assembly. The following half century has seen significant advances in
the first of these fields whereas the second has remained elusive, until recently. Here,
we review work that begins to shed light on Tol-Pal function in Gram-negative bacteria.
What emerges from these studies is that Tol-Pal is an energised system with fundamental,
interlinked roles in cell division – coordinating the re-structuring of peptidoglycan at
division sites and stabilising the connection between the outer membrane and underlying
cell wall. This latter role is achieved by Tol-Pal exploiting the proton motive force to
catalyse the accumulation of the outer membrane peptidoglycan associated lipoprotein Pal
at division sites while simultaneously mobilising Pal molecules from around the cell.
These studies begin to explain the diverse phenotypic outcomes of tol-pal
mutations, point to other cell envelope roles Tol-Pal may have and raise many new
questions.
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Affiliation(s)
- Joanna Szczepaniak
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
| | - Cara Press
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
| | - Colin Kleanthous
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford OX1 3QU, UK
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36
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Zhong Q, Deng Y, Qin H, Ou H, Qu Y, Ye J. Metabolic network and recovery mechanism of Escherichia coli associated with triclocarban stress. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 206:111140. [PMID: 32858325 DOI: 10.1016/j.ecoenv.2020.111140] [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: 02/15/2020] [Revised: 07/30/2020] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
Although the toxicity of triclocarban at molecular level has been investigated, the metabolic networks involved in regulating the stress processes are not clear. Whether the cells would maintain specific phenotypic characteristics after triclocarban stress is also needed to be clarified. In this study, Escherichia coli was selected as a model to elucidate the cellular metabolism response associated with triclocarban stress and the recovery metabolic network of the triclocarban-treated cells using the proteomics and metabolomics approaches. Results showed that triclocarban caused systematic metabolic remodeling. The adaptive pathways, glyoxylate shunt and acetate-switch were activated. These arrangements allowed cells to use more acetyl-CoA and to reduce carbon atom loss. The upregulation of NH3-dependent NAD+ synthetase complemented the NAD+ consumption by catabolism, maintaining the redox balance. The synthesis of 1-deoxy-D-xylulose-5-phosphate was suppressed, which would affect the accumulation of end products of its downstream pathway of isoprenoid synthesis. After recovery culture for 12 h, the state of cells returned to stability and the main impacts on metabolic network triggered by triclocarban have disappeared. However, drug resistance caused by long-term exposure to environmentally relevant concentration of triclocarban is still worthy of attention. The present study revealed the molecular events under triclocarban stress and clarified how triclocarban influence the metabolic networks.
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Affiliation(s)
- Qiao Zhong
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Ying Deng
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Huaming Qin
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Huase Ou
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China
| | - Yanfen Qu
- Zhongji Ecological Science & Technology Co., Ltd. Guangzhou, 511443, China
| | - Jinshao Ye
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 510632, China.
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37
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Bryant JA, Morris FC, Knowles TJ, Maderbocus R, Heinz E, Boelter G, Alodaini D, Colyer A, Wotherspoon PJ, Staunton KA, Jeeves M, Browning DF, Sevastsyanovich YR, Wells TJ, Rossiter AE, Bavro VN, Sridhar P, Ward DG, Chong ZS, Goodall EC, Icke C, Teo AC, Chng SS, Roper DI, Lithgow T, Cunningham AF, Banzhaf M, Overduin M, Henderson IR. Structure of dual BON-domain protein DolP identifies phospholipid binding as a new mechanism for protein localisation. eLife 2020; 9:62614. [PMID: 33315009 PMCID: PMC7806268 DOI: 10.7554/elife.62614] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/11/2020] [Indexed: 12/16/2022] Open
Abstract
The Gram-negative outer-membrane envelops the bacterium and functions as a permeability barrier against antibiotics, detergents, and environmental stresses. Some virulence factors serve to maintain the integrity of the outer membrane, including DolP (formerly YraP) a protein of unresolved structure and function. Here, we reveal DolP is a lipoprotein functionally conserved amongst Gram-negative bacteria and that loss of DolP increases membrane fluidity. We present the NMR solution structure for Escherichia coli DolP, which is composed of two BON domains that form an interconnected opposing pair. The C-terminal BON domain binds anionic phospholipids through an extensive membrane:protein interface. This interaction is essential for DolP function and is required for sub-cellular localisation of the protein to the cell division site, providing evidence of subcellular localisation of these phospholipids within the outer membrane. The structure of DolP provides a new target for developing therapies that disrupt the integrity of the bacterial cell envelope.
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Affiliation(s)
- Jack Alfred Bryant
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom
| | - Faye C Morris
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom
| | - Timothy J Knowles
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom.,School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Riyaz Maderbocus
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom.,Institute for Cancer and Genomic Sciences, University of Birmingham, Edgbaston, United Kingdom
| | - Eva Heinz
- Infection & Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
| | - Gabriela Boelter
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom
| | - Dema Alodaini
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom
| | - Adam Colyer
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom
| | - Peter J Wotherspoon
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom
| | - Kara A Staunton
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom
| | - Mark Jeeves
- Institute for Cancer and Genomic Sciences, University of Birmingham, Edgbaston, United Kingdom
| | - Douglas F Browning
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom
| | | | - Timothy J Wells
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom
| | - Amanda E Rossiter
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom
| | - Vassiliy N Bavro
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom
| | - Pooja Sridhar
- School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Douglas G Ward
- School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Zhi-Soon Chong
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Emily Ca Goodall
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom.,Institute for Molecular Bioscience, University of Queensland, St. Lucia, Australia
| | - Christopher Icke
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom.,Institute for Molecular Bioscience, University of Queensland, St. Lucia, Australia
| | - Alvin Ck Teo
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - Shu-Sin Chng
- Department of Chemistry, National University of Singapore, Singapore, Singapore.,School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - David I Roper
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - Trevor Lithgow
- Infection & Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia
| | - Adam F Cunningham
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom.,Institute of Inflammation and Immunotherapy, University of Birmingham, Edgbaston, United Kingdom
| | - Manuel Banzhaf
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom
| | - Michael Overduin
- School of Biosciences, University of Birmingham, Edgbaston, United Kingdom.,Department of Biochemistry, University of Alberta, Edmonton, Canada
| | - Ian R Henderson
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, United Kingdom.,Department of Chemistry, National University of Singapore, Singapore, Singapore
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38
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β-Barrel proteins tether the outer membrane in many Gram-negative bacteria. Nat Microbiol 2020; 6:19-26. [PMID: 33139883 PMCID: PMC7755725 DOI: 10.1038/s41564-020-00798-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 09/16/2020] [Indexed: 12/20/2022]
Abstract
Gram-negative bacteria have a cell envelope that comprises an outer membrane (OM), a peptidoglycan (PG) layer and an inner membrane (IM)1. The OM and PG are load-bearing, selectively permeable structures that are stabilized by cooperative interactions between IM and OM proteins2,3. In E. coli, Braun’s lipoprotein (Lpp) forms the only covalent tether between the OM and PG and is crucial for cell envelope stability4 but most other Gram-negative bacteria lack Lpp so it has been assumed that alternative mechanisms of OM stabilization are present5. We use a glycoproteomic analysis of PG to show that β-barrel OM proteins are covalently attached to PG in several Gram-negative species, including Coxiella burnetii, Agrobacterium tumefaciens and Legionella pneumophila. In C. burnetii, we found that four different types of covalent attachments occur between OM proteins and PG, with tethering of the β-barrel OM protein BbpA becoming most abundant in stationary phase and tethering of the lipoprotein LimB similar throughout the cell-cycle. Using a genetic approach, we demonstrate that the cell-cycle dependent tethering of BbpA is partly dependent on a developmentally regulated L,D transpeptidase (Ldt). We use our findings to propose a model of Gram-negative cell envelope stabilization that includes cell-cycle control and an expanded role for Ldts in covalently attaching surface proteins to PG.
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39
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Fontelo R, Soares da Costa D, Reis R, Novoa-Carballal R, Pashkuleva I. Bactericidal nanopatterns generated by block copolymer self-assembly. Acta Biomater 2020; 112:174-181. [PMID: 32525051 DOI: 10.1016/j.actbio.2020.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 05/27/2020] [Accepted: 06/02/2020] [Indexed: 02/08/2023]
Abstract
We describe the bactericidal capacity of nanopatterned surfaces created by self-assembly of block copolymers. Distinct nanotopographies were generated by spin-coating with polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) followed by solvent vapor annealing. We demonstrate that the bactericidal efficiency of the developed coatings depends on the morphology and the chemistry of the surface: cylindrical nanotopographies presenting both blocks at the surface have stronger bactericidal effect on Escherichia coli than micellar patterns with only PS exposed at the surface. The identified mechanism of bacterial death is a mechanical stress exerted by the nanostructures on the cell-wall. Moreover, the developed nanopatterns are not cytotoxic, which makes them an excellent option for coating of implantable materials and devices. The proposed approach represents an efficient tool in the fight against bacteria, which acts via compromising the bacterial wall integrity. STATEMENT OF SIGNIFICANCE: Bacterial infections represent an important risk during biomaterial implantation in surgeries due to the increase of antibiotic resistance. Bactericidal surfaces are a promising solution to avoid the use of antibiotics, but most of those systems do not allow mammalian cell survival. Nanopatterned silicon surfaces have demonstrated to be simultaneously bactericidal and allow mammalian cell culture but are made by physical methods (e.g. plasma etching) applicable to few materials and small surfaces. In this article we show that block copolymer self-assembly can be used to develop surfaces that kill bacteria (E. coli) but do not harm mammalian cells. Block copolymer self-assembly has the advantage of being applicable to many different types of substrates and large surface areas.
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40
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Outer Membrane Lipid Secretion and the Innate Immune Response to Gram-Negative Bacteria. Infect Immun 2020; 88:IAI.00920-19. [PMID: 32253250 DOI: 10.1128/iai.00920-19] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The outer membrane (OM) of Gram-negative bacteria is an asymmetric lipid bilayer that consists of inner leaflet phospholipids and outer leaflet lipopolysaccharides (LPS). The asymmetric character and unique biochemistry of LPS molecules contribute to the OM's ability to function as a molecular permeability barrier that protects the bacterium against hazards in the environment. Assembly and regulation of the OM have been extensively studied for understanding mechanisms of antibiotic resistance and bacterial defense against host immunity; however, there is little knowledge on how Gram-negative bacteria release their OMs into their environment to manipulate their hosts. Discoveries in bacterial lipid trafficking, OM lipid homeostasis, and host recognition of microbial patterns have shed new light on how microbes secrete OM vesicles (OMVs) to influence inflammation, cell death, and disease pathogenesis. Pathogens release OMVs that contain phospholipids, like cardiolipins, and components of LPS molecules, like lipid A endotoxins. These multiacylated lipid amphiphiles are molecular patterns that are differentially detected by host receptors like the Toll-like receptor 4/myeloid differentiation factor 2 complex (TLR4/MD-2), mouse caspase-11, and human caspases 4 and 5. We discuss how lipid ligands on OMVs engage these pattern recognition receptors on the membranes and in the cytosol of mammalian cells. We then detail how bacteria regulate OM lipid asymmetry, negative membrane curvature, and the phospholipid-to-LPS ratio to control OMV formation. The goal is to highlight intersections between OM lipid regulation and host immunity and to provide working models for how bacterial lipids influence vesicle formation.
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41
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Xu C, Soyfoo DM, Wu Y, Xu S. Virulence of Helicobacter pylori outer membrane proteins: an updated review. Eur J Clin Microbiol Infect Dis 2020; 39:1821-1830. [PMID: 32557327 PMCID: PMC7299134 DOI: 10.1007/s10096-020-03948-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/09/2020] [Indexed: 02/07/2023]
Abstract
Helicobacter pylori (H. pylori) infection is associated with some gastric diseases, such as gastritis, peptic ulcer, and gastric cancer. CagA and VacA are known virulence factors of H. pylori, which play a vital role in severe clinical outcomes. Additionally, the expression of outer membrane proteins (OMPs) helps H. pylori attach to gastric epithelial cells at the primary stage and increases the virulence of H. pylori. In this review, we have summarized the paralogs of H. pylori OMPs, their genomic loci, and the different receptors of OMPs identified so far. We focused on five OMPs, BabA (HopS), SabA (HopP), OipA (HopH), HopQ, and HopZ, and one family of OMPs: Hom. We highlight the coexpression of OMPs with other virulence factors and their relationship with clinical outcomes. In conclusion, OMPs are closely related to the pathogenic processes of adhesion, colonization, persistent infection, and severe clinical consequences. They are potential targets for the prevention and treatment of H. pylori–related diseases.
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Affiliation(s)
- Chenjing Xu
- Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | | | - Yao Wu
- Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Shunfu Xu
- Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu, China. .,Jiangsu Province Hospital, Nanjing Medical University, Nanjing, Jiangsu, China.
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42
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Swarbrick CMD, Nanson JD, Patterson EI, Forwood JK. Structure, function, and regulation of thioesterases. Prog Lipid Res 2020; 79:101036. [PMID: 32416211 DOI: 10.1016/j.plipres.2020.101036] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 01/15/2023]
Abstract
Thioesterases are present in all living cells and perform a wide range of important biological functions by catalysing the cleavage of thioester bonds present in a diverse array of cellular substrates. Thioesterases are organised into 25 families based on their sequence conservation, tertiary and quaternary structure, active site configuration, and substrate specificity. Recent structural and functional characterisation of thioesterases has led to significant changes in our understanding of the regulatory mechanisms that govern enzyme activity and their respective cellular roles. The resulting dogma changes in thioesterase regulation include mechanistic insights into ATP and GDP-mediated regulation by oligomerisation, the role of new key regulatory regions, and new insights into a conserved quaternary structure within TE4 family members. Here we provide a current and comparative snapshot of our understanding of thioesterase structure, function, and regulation across the different thioesterase families.
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Affiliation(s)
| | - Jeffrey D Nanson
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience, Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Edward I Patterson
- Centre for Neglected Tropical Diseases, Departments of Vector Biology and Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK
| | - Jade K Forwood
- School of Biomedical Sciences, Charles Sturt University, Boorooma Street, Wagga Wagga, New South Wales, Australia.
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43
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Yakhnina AA, Bernhardt TG. The Tol-Pal system is required for peptidoglycan-cleaving enzymes to complete bacterial cell division. Proc Natl Acad Sci U S A 2020; 117:6777-6783. [PMID: 32152098 PMCID: PMC7104345 DOI: 10.1073/pnas.1919267117] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Tol-Pal is a multiprotein system present in the envelope of Gram-negative bacteria. Inactivation of this widely conserved machinery compromises the outer membrane (OM) layer of these organisms, resulting in hypersensitivity to many antibiotics. Mutants in the tol-pal locus fail to complete division and form cell chains. This phenotype along with the localization of Tol-Pal components to the cytokinetic ring in Escherichia coli has led to the proposal that the primary function of the system is to promote OM constriction during division. Accordingly, a poorly constricted OM is believed to link the cell chains formed upon Tol-Pal inactivation. However, we show here that cell chains of E. coli tol-pal mutants are connected by an incompletely processed peptidoglycan (PG) layer. Genetic suppressors of this defect were isolated and found to overproduce OM lipoproteins capable of cleaving the glycan strands of PG. Among the factors promoting cell separation in mutant cells was a protein of previously unknown function (YddW), which we have identified as a divisome-localized glycosyl hydrolase that cleaves peptide-free PG glycans. Overall, our results indicate that the cell chaining defect of Tol-Pal mutants cannot simply be interpreted as a defect in OM constriction. Rather, the complex also appears to be required for the activity of several OM-localized enzymes with cell wall remodeling activity. Thus, the Tol-Pal system may play a more general role in coordinating OM invagination with PG remodeling at the division site than previously appreciated.
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Affiliation(s)
| | - Thomas G Bernhardt
- Department of Microbiology, Harvard Medical School, Boston, MA 02115;
- Howard Hughes Medical Institute, Boston, MA 02115
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44
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Szczepaniak J, Holmes P, Rajasekar K, Kaminska R, Samsudin F, Inns PG, Rassam P, Khalid S, Murray SM, Redfield C, Kleanthous C. The lipoprotein Pal stabilises the bacterial outer membrane during constriction by a mobilisation-and-capture mechanism. Nat Commun 2020; 11:1305. [PMID: 32161270 PMCID: PMC7066135 DOI: 10.1038/s41467-020-15083-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 02/13/2020] [Indexed: 11/24/2022] Open
Abstract
Coordination of outer membrane constriction with septation is critical to faithful division in Gram-negative bacteria and vital to the barrier function of the membrane. This coordination requires the recruitment of the peptidoglycan-binding outer-membrane lipoprotein Pal at division sites by the Tol system. Here, we show that Pal accumulation at Escherichia coli division sites is a consequence of three key functions of the Tol system. First, Tol mobilises Pal molecules in dividing cells, which otherwise diffuse very slowly due to their binding of the cell wall. Second, Tol actively captures mobilised Pal molecules and deposits them at the division septum. Third, the active capture mechanism is analogous to that used by the inner membrane protein TonB to dislodge the plug domains of outer membrane TonB-dependent nutrient transporters. We conclude that outer membrane constriction is coordinated with cell division by active mobilisation-and-capture of Pal at division septa by the Tol system.
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Affiliation(s)
| | - Peter Holmes
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- Department of Biochemistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Karthik Rajasekar
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- Evotec SE, 112-114 Innovation Drive, Milton Park, Abingdon, OX14 4RZ, UK
| | - Renata Kaminska
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Firdaus Samsudin
- Department of Chemistry, University of Southampton, University Road, Southampton, SO17 1BJ, UK
| | | | - Patrice Rassam
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- Laboratoire de Bioimagerie et Pathologie, UMR 7021, CNRS, Université de Strasbourg, Faculté de pharmacie, 74 Route du Rhin, 67401, Illkirch, France
| | - Syma Khalid
- Department of Chemistry, University of Southampton, University Road, Southampton, SO17 1BJ, UK
| | - Seán M Murray
- Max Planck Institute for Terrestrial Microbiology and LOEWE Centre for Synthetic Microbiology (SYNMIKRO), Karl-von-Frisch Strasse 16, 35043, Marburg, Germany
| | | | - Colin Kleanthous
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK.
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45
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Beeby M, Ferreira JL, Tripp P, Albers SV, Mitchell DR. Propulsive nanomachines: the convergent evolution of archaella, flagella and cilia. FEMS Microbiol Rev 2020; 44:253-304. [DOI: 10.1093/femsre/fuaa006] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 03/06/2020] [Indexed: 02/06/2023] Open
Abstract
ABSTRACT
Echoing the repeated convergent evolution of flight and vision in large eukaryotes, propulsive swimming motility has evolved independently in microbes in each of the three domains of life. Filamentous appendages – archaella in Archaea, flagella in Bacteria and cilia in Eukaryotes – wave, whip or rotate to propel microbes, overcoming diffusion and enabling colonization of new environments. The implementations of the three propulsive nanomachines are distinct, however: archaella and flagella rotate, while cilia beat or wave; flagella and cilia assemble at their tips, while archaella assemble at their base; archaella and cilia use ATP for motility, while flagella use ion-motive force. These underlying differences reflect the tinkering required to evolve a molecular machine, in which pre-existing machines in the appropriate contexts were iteratively co-opted for new functions and whose origins are reflected in their resultant mechanisms. Contemporary homologies suggest that archaella evolved from a non-rotary pilus, flagella from a non-rotary appendage or secretion system, and cilia from a passive sensory structure. Here, we review the structure, assembly, mechanism and homologies of the three distinct solutions as a foundation to better understand how propulsive nanomachines evolved three times independently and to highlight principles of molecular evolution.
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Affiliation(s)
- Morgan Beeby
- Department of Life Sciences, Frankland Road, Imperial College of London, London, SW7 2AZ, UK
| | - Josie L Ferreira
- Department of Life Sciences, Frankland Road, Imperial College of London, London, SW7 2AZ, UK
| | - Patrick Tripp
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, Schaenzlestrasse 1, 79211 Freiburg, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, Schaenzlestrasse 1, 79211 Freiburg, Germany
| | - David R Mitchell
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA
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46
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Banzhaf M, Yau HC, Verheul J, Lodge A, Kritikos G, Mateus A, Cordier B, Hov AK, Stein F, Wartel M, Pazos M, Solovyova AS, Breukink E, van Teeffelen S, Savitski MM, den Blaauwen T, Typas A, Vollmer W. Outer membrane lipoprotein NlpI scaffolds peptidoglycan hydrolases within multi-enzyme complexes in Escherichia coli. EMBO J 2020; 39:e102246. [PMID: 32009249 PMCID: PMC7049810 DOI: 10.15252/embj.2019102246] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 12/20/2019] [Accepted: 01/14/2020] [Indexed: 12/16/2022] Open
Abstract
The peptidoglycan (PG) sacculus provides bacteria with the mechanical strength to maintain cell shape and resist osmotic stress. Enlargement of the mesh‐like sacculus requires the combined activity of peptidoglycan synthases and hydrolases. In Escherichia coli, the activity of two PG synthases is driven by lipoproteins anchored in the outer membrane (OM). However, the regulation of PG hydrolases is less well understood, with only regulators for PG amidases having been described. Here, we identify the OM lipoprotein NlpI as a general adaptor protein for PG hydrolases. NlpI binds to different classes of hydrolases and can specifically form complexes with various PG endopeptidases. In addition, NlpI seems to contribute both to PG elongation and division biosynthetic complexes based on its localization and genetic interactions. Consistent with such a role, we reconstitute PG multi‐enzyme complexes containing NlpI, the PG synthesis regulator LpoA, its cognate bifunctional synthase, PBP1A, and different endopeptidases. Our results indicate that peptidoglycan regulators and adaptors are part of PG biosynthetic multi‐enzyme complexes, regulating and potentially coordinating the spatiotemporal action of PG synthases and hydrolases.
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Affiliation(s)
- Manuel Banzhaf
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - Hamish Cl Yau
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK
| | - Jolanda Verheul
- Bacterial Cell Biology & Physiology, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
| | - Adam Lodge
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK
| | - George Kritikos
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - André Mateus
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - Baptiste Cordier
- Microbial Morphogenesis and Growth Lab, Institut Pasteur, Paris, France
| | - Ann Kristin Hov
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - Frank Stein
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - Morgane Wartel
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany
| | - Manuel Pazos
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK
| | | | - Eefjan Breukink
- Membrane Biochemistry and Biophysics, Department of Chemistry, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | | | - Mikhail M Savitski
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany.,European Molecular Biology Laboratory, Structural & Computational Unit, Heidelberg, Germany
| | - Tanneke den Blaauwen
- Bacterial Cell Biology & Physiology, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
| | - Athanasios Typas
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany.,European Molecular Biology Laboratory, Structural & Computational Unit, Heidelberg, Germany
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK
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47
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Booth S, Lewis RJ. Structural basis for the coordination of cell division with the synthesis of the bacterial cell envelope. Protein Sci 2019; 28:2042-2054. [PMID: 31495975 PMCID: PMC6863701 DOI: 10.1002/pro.3722] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 08/29/2019] [Accepted: 08/29/2019] [Indexed: 01/02/2023]
Abstract
Bacteria are surrounded by a complex cell envelope made up of one or two membranes supplemented with a layer of peptidoglycan (PG). The envelope is responsible for the protection of bacteria against lysis in their oft-unpredictable environments and it contributes to cell integrity, morphology, signaling, nutrient/small-molecule transport, and, in the case of pathogenic bacteria, host-pathogen interactions and virulence. The cell envelope requires considerable remodeling during cell division in order to produce genetically identical progeny. Several proteinaceous machines are responsible for the homeostasis of the cell envelope and their activities must be kept coordinated in order to ensure the remodeling of the envelope is temporally and spatially regulated correctly during multiple cycles of cell division and growth. This review aims to highlight the complexity of the components of the cell envelope, but focusses specifically on the molecular apparatuses involved in the synthesis of the PG wall, and the degree of cross talk necessary between the cell division and the cell wall remodeling machineries to coordinate PG remodeling during division. The current understanding of many of the proteins discussed here has relied on structural studies, and this review concentrates particularly on this structural work.
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Affiliation(s)
- Simon Booth
- Institute for Cell and Molecular Biosciences, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
| | - Richard J. Lewis
- Institute for Cell and Molecular Biosciences, Faculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
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48
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Pichoff S, Du S, Lutkenhaus J. Roles of FtsEX in cell division. Res Microbiol 2019; 170:374-380. [PMID: 31376483 PMCID: PMC6899183 DOI: 10.1016/j.resmic.2019.07.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 07/09/2019] [Accepted: 07/16/2019] [Indexed: 02/04/2023]
Abstract
FtsEX is a member of a small subclass of ABC transporters that uses mechano-transmission to perform work in the periplasm. FtsEX controls periplasmic peptidoglycan (PG) hydrolase activities in many Gram negative and positive organisms to ensure the safe separation of daughter cells during division. In these organisms FtsEX localizes to the Z ring and uses its ATPase activity to regulate its periplasmic effectors. In Escherichia coli, FtsEX also participates in building the divisome and coordinates PG synthesis with PG hydrolysis. This review discusses studies that are beginning to elucidate the mechanisms of FtsEX's various roles in cell division.
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Affiliation(s)
- Sebastien Pichoff
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Shishen Du
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Joe Lutkenhaus
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, 66160, USA.
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49
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Zheng H, Ji Z, Roy KR, Gao M, Pan Y, Cai X, Wang L, Li W, Chang CH, Kaweeteerawat C, Chen C, Xia T, Zhao Y, Li R. Engineered Graphene Oxide Nanocomposite Capable of Preventing the Evolution of Antimicrobial Resistance. ACS NANO 2019; 13:11488-11499. [PMID: 31566947 DOI: 10.1021/acsnano.9b04970] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Antimicrobial resistance (AMR) is spreading worldwide and keeps evolving to adapt to antibiotics, causing increasing threats in clinics, which necessitates the exploration of antimicrobial agents for not only killing of resistant cells but also prevention of AMR progression. However, so far, there has been no effective approach. Herein, we designed lanthanum hydroxide and graphene oxide nanocomposites (La@GO) to confer a synergistic bactericidal effect in all tested resistant strains. More importantly, long-term exposure of E. coli (AMR) to subminimum inhibitory concentrations of La@GO does not trigger detectable secondary resistance, while conventional antibiotics and silver nanoparticles lead to a 16- to 64-fold increase in tolerance. The inability of E. coli to evolve resistance to La@GO is likely due to a distinctive extracellular multitarget invasion killing mechanism involving lipid dephosphorylation, lipid peroxidation, and peptidoglycan disruption. Overall, our results highlight La@GO nanocomposites as a promising solution to combating resistant bacteria without inducing the evolution of AMR.
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Affiliation(s)
- Huizhen Zheng
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions , Soochow University , Suzhou , 215123 , Jiangsu , China
| | - Zhaoxia Ji
- Division of Nanomedicine, Department of Medicine, California NanoSystems Institute , University of California , Los Angeles , California 90095 , United States
- Living Proof, Inc. , Cambridge , Massachusetts 02142 , United States
| | - Kevin R Roy
- Department of Genetics, School of Medicine , Stanford University , Palo Alto , California 94304 , United States
| | - Meng Gao
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions , Soochow University , Suzhou , 215123 , Jiangsu , China
| | - Yanxia Pan
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions , Soochow University , Suzhou , 215123 , Jiangsu , China
| | - Xiaoming Cai
- School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases , Soochow University , Suzhou , 215123 , Jiangsu , China
| | - Liming Wang
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety , Institute of High Energy Physics, Chinese Academy of Sciences (CAS) , Beijing , 100049 , China
| | - Wei Li
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions , Soochow University , Suzhou , 215123 , Jiangsu , China
| | - Chong Hyun Chang
- Division of Nanomedicine, Department of Medicine, California NanoSystems Institute , University of California , Los Angeles , California 90095 , United States
| | - Chitrada Kaweeteerawat
- National Nanotechnology Center (NANOTEC), NSTDA Characterization and Testing Center (NCTC), National Science and Technology Development Agency (NSTDA) , Klong Nueng , 12120 , Thailand
| | - Chunying Chen
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety & CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology of China, Chinese Academy of Sciences (CAS) , Beijing , 100190 , China
| | - Tian Xia
- Division of Nanomedicine, Department of Medicine, California NanoSystems Institute , University of California , Los Angeles , California 90095 , United States
| | - Yuliang Zhao
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety & CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology of China, Chinese Academy of Sciences (CAS) , Beijing , 100190 , China
| | - Ruibin Li
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions , Soochow University , Suzhou , 215123 , Jiangsu , China
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50
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Giannini E, González LJ, Vila AJ. A simple protocol to characterize bacterial cell-envelope lipoproteins in a native-like environment. Protein Sci 2019; 28:2004-2010. [PMID: 31518027 DOI: 10.1002/pro.3728] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 01/04/2023]
Abstract
Physiological conditions in living cells are strictly regulated to allow, optimize, and coordinate biological processes. The bacterial cell envelope is the compartment where the communication with the external environment takes place. This involves membrane proteins, key players in many biological processes that ensure bacterial survival. The biochemical characterization of membrane proteins, either integral, lipidated or peripheral is challenging due to their mixed protein-lipid nature, making it difficult to purify and obtain considerable amounts of samples. In contrast to integral membrane proteins, lipidated proteins are usually purified as truncated soluble versions, neglecting the impact of the membrane environment. Here we report a simple and robust protocol to characterize bacterial lipidated proteins in spheroplasts from Escherichia coli using a β-lactamase as a model. The Metallo-β-lactamase NDM-1 is an enzyme anchored to the inner leaflet of the outer membrane of Gram-negative bacteria. Kinetic parameters and stability of the lipidated NDM-1 and the soluble unbound version (NDM-1 C26A) were measured in spheroplasts and periplasm, respectively. These studies revealed that membrane anchoring increases the KM of the enzyme, consequently decreasing the catalytic efficiency, while not affecting its kinetic stability. This approach can be used to characterize lipidated proteins avoiding the purification step while mimicking its native environment. This approach also helps in filling the gap between in vitro and in vivo studies.
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Affiliation(s)
- Estefanía Giannini
- Laboratorio de Metaloproteínas, Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina
| | - Lisandro J González
- Laboratorio de Metaloproteínas, Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina.,Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Alejandro J Vila
- Laboratorio de Metaloproteínas, Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Rosario, Argentina.,Área Biofísica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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