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Chen Y, Goh YX, Li P, Guan J, Chao Y, Qu H, Ou HY, Wang X. RES-Xre toxin-antitoxin locus knaAT maintains the stability of the virulence plasmid in Klebsiella pneumoniae. Emerg Microbes Infect 2024; 13:2316814. [PMID: 38323903 PMCID: PMC10896132 DOI: 10.1080/22221751.2024.2316814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Accepted: 02/06/2024] [Indexed: 02/08/2024]
Abstract
Hypervirulent Klebsiella pneumoniae isolates have been increasingly reported worldwide, especially hypervirulent drug-resistant variants owing to the acquisition of a mobilizable virulence plasmid by a carbapenem-resistant strain. This pLVPK-like mobilizable plasmid encodes various virulence factors; however, information about its genetic stability is lacking. This study aimed to investigate the type II toxin-antitoxin (TA) modules that facilitate the virulence plasmid to remain stable in K. pneumoniae. More than 3,000 TA loci in 2,000 K. pneumoniae plasmids were examined for their relationship with plasmid cargo genes. TA loci from the RES-Xre family were highly correlated with virulence plasmids of hypervirulent K. pneumoniae. Overexpression of the RES toxin KnaT, encoded by the virulence plasmid-carrying RES-Xre locus knaAT, halts the cell growth of K. pneumoniae and E. coli, whereas co-expression of the cognate Xre antitoxin KnaA neutralizes the toxicity of KnaT. knaA and knaT were co-transcribed, representing the characteristics of a type II TA module. The knaAT deletion mutation gradually lost its virulence plasmid in K. pneumoniae, whereas the stability of the plasmid in E. coli was enhanced by adding knaAT, which revealed that the knaAT operon maintained the genetic stability of the large virulence plasmid in K. pneumoniae. String tests and mouse lethality assays subsequently confirmed that a loss of the virulence plasmid resulted in reduced pathogenicity of K. pneumoniae. These findings provide important insights into the role of the RES-Xre TA pair in stabilizing virulence plasmids and disseminating virulence genes in K. pneumoniae.
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Affiliation(s)
- Yongkui Chen
- Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China
- State Key Laboratory of Microbial Metabolism, Joint International Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Ying-Xian Goh
- State Key Laboratory of Microbial Metabolism, Joint International Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Peifei Li
- State Key Laboratory of Microbial Metabolism, Joint International Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Jiahao Guan
- State Key Laboratory of Microbial Metabolism, Joint International Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Yanjie Chao
- The Center for Microbes, Development and Health (CMDH), CAS Key Laboratory of Molecular Virology and Immunology, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, People’s Republic of China
| | - Hongping Qu
- Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China
| | - Hong-Yu Ou
- State Key Laboratory of Microbial Metabolism, Joint International Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Xiaoli Wang
- Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China
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2
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Findlay J, Poirel L, Cherkaoui A, Schrenzel J, Nordmann P. Characterisation of a novel AmpC beta-lactamase, DHA-33, resistant to inhibition by cloxacillin. Diagn Microbiol Infect Dis 2024; 109:116356. [PMID: 38763036 DOI: 10.1016/j.diagmicrobio.2024.116356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/15/2024] [Accepted: 05/16/2024] [Indexed: 05/21/2024]
Abstract
Plasmid-encoded DHA-type AmpCs have been extensively reported in Enterobacterales. The expression of the genes encoding these plasmid-mediated enzymes are inducible and these enzymes are capable of conferring resistance to a wide spectrum of beta-lactams including penicillins and broad-spectrum cephalosporins. The identification of infections caused by AmpC-producing bacteria is a necessity, both for infection control/epidemiology purposes and to inform treatment choices. A common testing method for AmpC production in the clinical laboratory setting is to supplement Mueller-Hinton agar plates used for antibiotic disk diffusion with cloxacillin, a potent inhibitor of AmpC enzymes. Here we describe a novel DHA variant, produced by a clinical Escherichia coli isolate, which is resistant to cloxacillin inhibition.
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Affiliation(s)
- Jacqueline Findlay
- Medical and Molecular Microbiology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland.
| | - Laurent Poirel
- Medical and Molecular Microbiology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland; Swiss National Reference Center for Emerging Antibiotic Resistance (NARA), University of Fribourg, Fribourg, Switzerland
| | - Abdessalam Cherkaoui
- Bacteriology Laboratory, Division of Laboratory Medicine, Department of Diagnostics, Geneva University Hospitals, Geneva, Switzerland
| | - Jacques Schrenzel
- Bacteriology Laboratory, Division of Laboratory Medicine, Department of Diagnostics, Geneva University Hospitals, Geneva, Switzerland; Genomic Research Laboratory, University of Geneva, Geneva, Switzerland
| | - Patrice Nordmann
- Medical and Molecular Microbiology, Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland; Swiss National Reference Center for Emerging Antibiotic Resistance (NARA), University of Fribourg, Fribourg, Switzerland
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3
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Jagodnik J, Darfeuille F, Guillier M. Disentangling the pseudoknots of toxin translation. Proc Natl Acad Sci U S A 2024; 121:e2411591121. [PMID: 39024107 DOI: 10.1073/pnas.2411591121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024] Open
Affiliation(s)
- Jonathan Jagodnik
- Microbial Gene Expression department, UMR8261 CNRS, Université Paris Cité, Institut de Biologie Physico-Chimique, Paris 75005, France
| | - Fabien Darfeuille
- University of Bordeaux, Department of Technology for Health, INSERM U1212, CNRS UMR 5320, ARN: Régulation Naturelle et Artificielle (ARNA) Laboratory, Bordeaux F-33000, France
| | - Maude Guillier
- Microbial Gene Expression department, UMR8261 CNRS, Université Paris Cité, Institut de Biologie Physico-Chimique, Paris 75005, France
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4
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Mittal P, Sinha AK, Pandiyan A, Kumari L, Ray MK, Pavankumar TL. A type II toxin-antitoxin system is responsible for the cell death at low temperature in Pseudomonas syringae Lz4W lacking RNase R. J Biol Chem 2024:107600. [PMID: 39059490 DOI: 10.1016/j.jbc.2024.107600] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 06/17/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024] Open
Abstract
RNase R (encoded by the rnr gene) is a highly processive 3' → 5' exoribonuclease essential for the growth of the psychrotrophic bacterium P. syringae Lz4W at low temperature. The cell death of a rnr deletion mutant at low temperature has been previously attributed to the processing defects in 16S rRNA, defective ribosomal assembly and inefficient protein synthesis. We recently showed that RNase R is required to protect P. syringae Lz4W from DNA damage and oxidative stress, independent of its exoribonuclease activity. Here, we show that the processing defect in 16S rRNA does not cause cell death of the rnr mutant of P. syringae at low temperature. Our results demonstrate that the rnr mutant of P. syringae Lz4W, complemented with a RNase R deficient in exoribonuclease function (RNase RD284A) is defective in 16S rRNA processing but can grow at 4 oC. This suggested that the processing defect in ribosomal RNAs is not a cause of the cold sensitivity of the rnr mutant. We further show that the rnr mutant accumulates copies of the indigenous plasmid of P. syringae Lz4W, pLz4W, that bears a type II toxin-antitoxin system (psA-psT). This phenotype was rescued by over-expressing antitoxin psA in the rnr mutant, suggesting that activation of the type II toxin-antitoxin system leads to cold sensitivity of the rnr mutant of P. syringae Lz4W. Here, we report a previously unknown functional relationship between the cold sensitivity of the rnr mutant and a type II toxin-antitoxin system in P. syringae Lz4W.
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Affiliation(s)
- Pragya Mittal
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Uppal Road, Hyderabad-500007, India; Celtic Renewables Ltd, Edinburgh Napier University, 9 Sighthill Court, Edinburgh, EH11 4BN, UK.
| | - Anurag K Sinha
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Uppal Road, Hyderabad-500007, India; National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Apuratha Pandiyan
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Uppal Road, Hyderabad-500007, India; Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Punjab, India
| | - Leela Kumari
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Uppal Road, Hyderabad-500007, India
| | - Malay K Ray
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Uppal Road, Hyderabad-500007, India
| | - Theetha L Pavankumar
- Centre for Cellular and Molecular Biology (CCMB), Council of Scientific and Industrial Research (CSIR), Uppal Road, Hyderabad-500007, India; Department of Microbiology and Molecular Genetics, and Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA.
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5
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Prins RC, Billerbeck S. The signal peptide of yeast killer toxin K2 confers producer self-protection and allows conversion into a modular toxin-immunity system. Cell Rep 2024; 43:114449. [PMID: 38985680 DOI: 10.1016/j.celrep.2024.114449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 05/30/2024] [Accepted: 06/20/2024] [Indexed: 07/12/2024] Open
Abstract
Some microbial toxins also target the producer species itself, necessitating a means of self-protection. The M2 double-stranded RNA (dsRNA) killer virus in Saccharomyces cerevisiae contains a single open reading frame (ORF) encoding both the secreted pore-forming toxin K2 as well as a cognate immunity factor. Here, we show that expression of a 49-amino acid N-terminal peptide from the K2 precursor is both necessary and sufficient for immunity. This immunity peptide simultaneously functions as a signal peptide for toxin secretion and protects the cell against the cytotoxic K2 α subunit. The K2 toxin and immunity factor can be functionally separated into two ORFs, yielding a modular toxin-immunity system. This case further shows how a (signal) peptide can carry the potential for providing cellular protection against an antimicrobial toxin.
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Affiliation(s)
- Rianne C Prins
- Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands
| | - Sonja Billerbeck
- Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands.
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6
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Mets T, Kurata T, Ernits K, Johansson MJO, Craig SZ, Evora GM, Buttress JA, Odai R, Wallant KC, Nakamoto JA, Shyrokova L, Egorov AA, Doering CR, Brodiazhenko T, Laub MT, Tenson T, Strahl H, Martens C, Harms A, Garcia-Pino A, Atkinson GC, Hauryliuk V. Mechanism of phage sensing and restriction by toxin-antitoxin-chaperone systems. Cell Host Microbe 2024; 32:1059-1073.e8. [PMID: 38821063 DOI: 10.1016/j.chom.2024.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/10/2024] [Accepted: 05/07/2024] [Indexed: 06/02/2024]
Abstract
Toxin-antitoxins (TAs) are prokaryotic two-gene systems composed of a toxin neutralized by an antitoxin. Toxin-antitoxin-chaperone (TAC) systems additionally include a SecB-like chaperone that stabilizes the antitoxin by recognizing its chaperone addiction (ChAD) element. TACs mediate antiphage defense, but the mechanisms of viral sensing and restriction are unexplored. We identify two Escherichia coli antiphage TAC systems containing host inhibition of growth (HigBA) and CmdTA TA modules, HigBAC and CmdTAC. HigBAC is triggered through recognition of the gpV major tail protein of phage λ. Chaperone HigC recognizes gpV and ChAD via analogous aromatic molecular patterns, with gpV outcompeting ChAD to trigger toxicity. For CmdTAC, the CmdT ADP-ribosyltransferase toxin modifies mRNA to halt protein synthesis and limit phage propagation. Finally, we establish the modularity of TACs by creating a hybrid broad-spectrum antiphage system combining the CmdTA TA warhead with a HigC chaperone phage sensor. Collectively, these findings reveal the potential of TAC systems in broad-spectrum antiphage defense.
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Affiliation(s)
- Toomas Mets
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; University of Tartu, Institute of Technology, 50411 Tartu, Estonia
| | - Tatsuaki Kurata
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Karin Ernits
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Marcus J O Johansson
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Sophie Z Craig
- Cellular and Molecular Microbiology (CM2), Faculté des Sciences, Université Libre de Bruxelles (ULB), Campus La Plaine, Building BC, Room 1C4203, Boulevard du Triomphe, 1050 Brussels, Belgium
| | - Gabriel Medina Evora
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; Cellular and Molecular Microbiology (CM2), Faculté des Sciences, Université Libre de Bruxelles (ULB), Campus La Plaine, Building BC, Room 1C4203, Boulevard du Triomphe, 1050 Brussels, Belgium
| | - Jessica A Buttress
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Roni Odai
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Kyo Coppieters't Wallant
- Centre for Structural Biology and Bioinformatics, Université Libre de Bruxelles (ULB), Boulevard du Triomphe, Building BC, 1050 Bruxelles, Belgium
| | - Jose A Nakamoto
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Lena Shyrokova
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Artyom A Egorov
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | | | | | - Michael T Laub
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Tanel Tenson
- University of Tartu, Institute of Technology, 50411 Tartu, Estonia
| | - Henrik Strahl
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Chloe Martens
- Centre for Structural Biology and Bioinformatics, Université Libre de Bruxelles (ULB), Boulevard du Triomphe, Building BC, 1050 Bruxelles, Belgium
| | - Alexander Harms
- ETH Zurich, Institute of Food, Nutrition and Health, 8092 Zürich, Switzerland
| | - Abel Garcia-Pino
- Cellular and Molecular Microbiology (CM2), Faculté des Sciences, Université Libre de Bruxelles (ULB), Campus La Plaine, Building BC, Room 1C4203, Boulevard du Triomphe, 1050 Brussels, Belgium.
| | - Gemma C Atkinson
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; Virus Centre, Lund University, Lund, Sweden.
| | - Vasili Hauryliuk
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; University of Tartu, Institute of Technology, 50411 Tartu, Estonia; Virus Centre, Lund University, Lund, Sweden; Science for Life Laboratory, Lund, Sweden.
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7
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Kurata T, Takegawa M, Ohira T, Syroegin EA, Atkinson GC, Johansson MJO, Polikanov YS, Garcia-Pino A, Suzuki T, Hauryliuk V. Toxic Small Alarmone Synthetase FaRel2 inhibits translation by pyrophosphorylating tRNA Gly and tRNA Thr. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.05.602228. [PMID: 39005314 PMCID: PMC11245113 DOI: 10.1101/2024.07.05.602228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Translation-targeting toxic Small Alarmone Synthetases (toxSAS) are effectors of bacterial Toxin-Antitoxin systems that pyrophosphorylate the 3'-CCA end of tRNA to prevent aminoacylation. toxSAS are implicated in antiphage immunity: phage detection triggers the toxSAS activity to shut down viral production. We show that the toxSAS FaRel2 inspects the tRNA acceptor stem to specifically select tRNAGly and tRNAThr. The 1st, 2nd, 4th and 5th base pairs the stem act as the specificity determinants. We show that the toxSASs PhRel2 and CapRelSJ46 differ in tRNA specificity from FaRel2, and rationalise this through structural modelling: while the universal 3'-CCA end slots into a highly conserved CCA recognition groove, the acceptor stem recognition region is variable across toxSAS diversity. As phages use tRNA isoacceptors to overcome tRNA-targeting defences, we hypothesise that highly evolvable modular tRNA recognition allows for the escape of viral countermeasures through tRNA substrate specificity switching.
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Affiliation(s)
- Tatsuaki Kurata
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Masaki Takegawa
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656
| | - Takayuki Ohira
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656
| | - Egor A Syroegin
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Gemma C Atkinson
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | | | - Yury S Polikanov
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Abel Garcia-Pino
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Boulevard du Triomphe, Building BC, (1C4 203), 1050 Brussels, Belgium
- WELBIO, Avenue Hippocrate 75, 1200 Brussels, Belgium
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656
| | - Vasili Hauryliuk
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- University of Tartu, Institute of Technology, Tartu, Estonia
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8
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Wang C, Han M, Min Y, Hu J, Pan Y, Huang L, Nie J. Colletotrichum fructicola co-opts cytotoxic ribonucleases that antagonize host competitive microorganisms to promote infection. mBio 2024:e0105324. [PMID: 38953357 DOI: 10.1128/mbio.01053-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Accepted: 06/13/2024] [Indexed: 07/04/2024] Open
Abstract
Phytopathogens secrete numerous molecules into the environment to establish a microbial niche and facilitate host infection. The phytopathogenic fungus Colletotrichum fructicola, which causes pear anthracnose, can colonize different plant tissues like leaves and fruits, which are occupied by a diversity of microbes. We speculate that this fungus produces antimicrobial effectors to outcompete host-associated competitive microorganisms. Herein, we identified two secreted ribonucleases, CfRibo1 and CfRibo2, from the C. fructicola secretome. The two ribonucleases both possess ribonuclease activity and showed cytotoxicity in Nicotianan benthamiana without triggering immunity in an enzymatic activity-dependent manner. CfRibo1 and CfRibo2 recombinant proteins exhibited toxicity against Escherichia coli, Saccharomyces cerevisiae, and, importantly, the phyllosphere microorganisms isolated from the pear host. Among these isolated microbial strains, Bacillus altitudinis is a pathogenic bacterium causing pear soft rot. Strikingly, CfRibo1 and CfRibo2 were found to directly antagonize B. altitudinis to facilitate C. fructicola infection. More importantly, CfRibo1 and CfRibo2 functioned as essential virulence factors of C. fructicola in the presence of host-associated microorganisms. Further analysis revealed these two ribonucleases are widely distributed in fungi and are undergoing purifying selection. Our results provide the first evidence of antimicrobial effectors in Colletotrichum fungi and extend the functional diversity of fungal ribonucleases in plant-pest-environment interactions. IMPORTANCE Colletotrichum fructicola is emerging as a devastating pathogenic fungus causing anthracnose in various crops in agriculture, and understanding how this fungus establishes successful infection is of great significance for anthracnose disease management. Fungi are known to produce secreted effectors as weapons to promote virulence. Considerable progress has been made in elucidating how effectors manipulate plant immunity; however, their importance in modulating environmental microbes is frequently neglected. The present study identified two secreted ribonucleases, CfRibo1 and CfRibo2, as antimicrobial effectors of C. fructicola. These two proteins both possess toxicity to pear phyllosphere microorganisms, and they efficiently antagonize competitive microbes to facilitate the infection of pear hosts. This study represents the first evidence of antimicrobial effectors in Colletotrichum fungi, and we consider that CfRibo1 and CfRibo2 could be targeted for anthracnose disease management in diverse crops in the future.
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Affiliation(s)
- Chunhao Wang
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
| | - Mengqing Han
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
| | - Yanyan Min
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
| | - Jiayi Hu
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
| | - Yuemin Pan
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
| | - Lili Huang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Northwest A&F University, Yangling, Shaanxi, China
| | - Jiajun Nie
- Anhui Province Key Laboratory of Crop Integrated Pest Management, Anhui Agricultural University, Hefei, China
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9
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Grabe GJ, Giorgio RT, Wieczór M, Gollan B, Sargen M, Orozco M, Hare SA, Helaine S. Molecular stripping underpins derepression of a toxin-antitoxin system. Nat Struct Mol Biol 2024; 31:1050-1060. [PMID: 38538913 DOI: 10.1038/s41594-024-01253-2] [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: 07/03/2023] [Accepted: 02/14/2024] [Indexed: 04/04/2024]
Abstract
Transcription factors control gene expression; among these, transcriptional repressors must liberate the promoter for derepression to occur. Toxin-antitoxin (TA) modules are bacterial elements that autoregulate their transcription by binding the promoter in a T:A ratio-dependent manner, known as conditional cooperativity. The molecular basis of how excess toxin triggers derepression has remained elusive, largely because monitoring the rearrangement of promoter-repressor complexes, which underpin derepression, is challenging. Here, we dissect the autoregulation of the Salmonella enterica tacAT3 module. Using a combination of assays targeting DNA binding and promoter activity, as well as structural characterization, we determine the essential TA and DNA elements required to control transcription, and we reconstitute a repression-to-derepression path. We demonstrate that excess toxin triggers molecular stripping of the repressor complex off the DNA through multiple allosteric changes causing DNA distortion and ultimately leading to derepression. Thus, our work provides important insight into the mechanisms underlying conditional cooperativity.
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Affiliation(s)
- Grzegorz J Grabe
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
| | - Rachel T Giorgio
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Miłosz Wieczór
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Bridget Gollan
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Molly Sargen
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Modesto Orozco
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Stephen A Hare
- School of Life Sciences, University of Sussex, Brighton, UK
| | - Sophie Helaine
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
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10
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Schaible GA, Jay ZJ, Cliff J, Schulz F, Gauvin C, Goudeau D, Malmstrom RR, Ruff SE, Edgcomb V, Hatzenpichler R. Multicellular magnetotactic bacteria are genetically heterogeneous consortia with metabolically differentiated cells. PLoS Biol 2024; 22:e3002638. [PMID: 38990824 PMCID: PMC11239054 DOI: 10.1371/journal.pbio.3002638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 04/24/2024] [Indexed: 07/13/2024] Open
Abstract
Consortia of multicellular magnetotactic bacteria (MMB) are currently the only known example of bacteria without a unicellular stage in their life cycle. Because of their recalcitrance to cultivation, most previous studies of MMB have been limited to microscopic observations. To study the biology of these unique organisms in more detail, we use multiple culture-independent approaches to analyze the genomics and physiology of MMB consortia at single-cell resolution. We separately sequenced the metagenomes of 22 individual MMB consortia, representing 8 new species, and quantified the genetic diversity within each MMB consortium. This revealed that, counter to conventional views, cells within MMB consortia are not clonal. Single consortia metagenomes were then used to reconstruct the species-specific metabolic potential and infer the physiological capabilities of MMB. To validate genomic predictions, we performed stable isotope probing (SIP) experiments and interrogated MMB consortia using fluorescence in situ hybridization (FISH) combined with nanoscale secondary ion mass spectrometry (NanoSIMS). By coupling FISH with bioorthogonal noncanonical amino acid tagging (BONCAT), we explored their in situ activity as well as variation of protein synthesis within cells. We demonstrate that MMB consortia are mixotrophic sulfate reducers and that they exhibit metabolic differentiation between individual cells, suggesting that MMB consortia are more complex than previously thought. These findings expand our understanding of MMB diversity, ecology, genomics, and physiology, as well as offer insights into the mechanisms underpinning the multicellular nature of their unique lifestyle.
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Affiliation(s)
- George A. Schaible
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, United States of America
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana, United States of America
| | - Zackary J. Jay
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, United States of America
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana, United States of America
- Thermal Biology Institute, Montana State University, Bozeman, Montana, United States of America
| | - John Cliff
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington, United States of America
| | - Frederik Schulz
- Department of Energy Joint Genome Institute, Berkeley, California, United States of America
| | - Colin Gauvin
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana, United States of America
- Thermal Biology Institute, Montana State University, Bozeman, Montana, United States of America
| | - Danielle Goudeau
- Department of Energy Joint Genome Institute, Berkeley, California, United States of America
| | - Rex R. Malmstrom
- Department of Energy Joint Genome Institute, Berkeley, California, United States of America
| | - S. Emil Ruff
- Ecosystems Center and Bay Paul Center, Marine Biological Laboratory, Woods Hole, Massachusetts, United States of America
| | - Virginia Edgcomb
- Woods Hole Oceanographic Institution, Falmouth, Massachusetts, United States of America
| | - Roland Hatzenpichler
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, United States of America
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana, United States of America
- Thermal Biology Institute, Montana State University, Bozeman, Montana, United States of America
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana, United States of America
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11
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Gosain TP, Chugh S, Rizvi ZA, Chauhan NK, Kidwai S, Thakur KG, Awasthi A, Singh R. Mycobacterium tuberculosis strain with deletions in menT3 and menT4 is attenuated and confers protection in mice and guinea pigs. Nat Commun 2024; 15:5467. [PMID: 38937463 PMCID: PMC11211403 DOI: 10.1038/s41467-024-49246-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 05/29/2024] [Indexed: 06/29/2024] Open
Abstract
The genome of Mycobacterium tuberculosis encodes for a large repertoire of toxin-antitoxin systems. In the present study, MenT3 and MenT4 toxins belonging to MenAT subfamily of TA systems have been functionally characterized. We demonstrate that ectopic expression of these toxins inhibits bacterial growth and this is rescued upon co-expression of their cognate antitoxins. Here, we show that simultaneous deletion of menT3 and menT4 results in enhanced susceptibility of M. tuberculosis upon exposure to oxidative stress and attenuated growth in guinea pigs and mice. We observed reduced expression of transcripts encoding for proteins that are essential or required for intracellular growth in mid-log phase cultures of ΔmenT4ΔT3 compared to parental strain. Further, the transcript levels of proteins involved in efficient bacterial clearance were increased in lung tissues of ΔmenT4ΔT3 infected mice relative to parental strain infected mice. We show that immunization of mice and guinea pigs with ΔmenT4ΔT3 confers significant protection against M. tuberculosis infection. Remarkably, immunization of mice with ΔmenT4ΔT3 results in increased antigen-specific TH1 bias and activated memory T cell response. We conclude that MenT3 and MenT4 are important for M. tuberculosis pathogenicity and strains lacking menT3 and menT4 have the potential to be explored further as vaccine candidates.
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Affiliation(s)
- Tannu Priya Gosain
- Centre for Tuberculosis Research, Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, 121001, India
| | - Saurabh Chugh
- Centre for Tuberculosis Research, Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, 121001, India
| | - Zaigham Abbas Rizvi
- Centre for Immunobiology and Immunotherapy, Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, 121001, India
| | - Neeraj Kumar Chauhan
- Centre for Tuberculosis Research, Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, 121001, India
| | - Saqib Kidwai
- Centre for Tuberculosis Research, Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, 121001, India
| | - Krishan Gopal Thakur
- Structural Biology Laboratory, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh, 160036, India
| | - Amit Awasthi
- Centre for Immunobiology and Immunotherapy, Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, 121001, India
| | - Ramandeep Singh
- Centre for Tuberculosis Research, Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, 121001, India.
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12
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Liu J, Yashiro Y, Sakaguchi Y, Suzuki T, Tomita K. Substrate specificity of Mycobacterium tuberculosis tRNA terminal nucleotidyltransferase toxin MenT3. Nucleic Acids Res 2024; 52:5987-6001. [PMID: 38485701 PMCID: PMC11162799 DOI: 10.1093/nar/gkae177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 02/13/2024] [Accepted: 02/28/2024] [Indexed: 06/11/2024] Open
Abstract
Mycobacterium tuberculosis transfer RNA (tRNA) terminal nucleotidyltransferase toxin, MenT3, incorporates nucleotides at the 3'-CCA end of tRNAs, blocking their aminoacylation and inhibiting protein synthesis. Here, we show that MenT3 most effectively adds CMPs to the 3'-CCA end of tRNA. The crystal structure of MenT3 in complex with CTP reveals a CTP-specific nucleotide-binding pocket. The 4-NH2 and the N3 and O2 atoms of cytosine in CTP form hydrogen bonds with the main-chain carbonyl oxygen of P120 and the side chain of R238, respectively. MenT3 expression in Escherichia coli selectively reduces the levels of seryl-tRNASers, indicating specific inactivation of tRNASers by MenT3. Consistently, MenT3 incorporates CMPs into tRNASer most efficiently, among the tested E. coli tRNA species. The longer variable loop unique to class II tRNASers is crucial for efficient CMP incorporation into tRNASer by MenT3. Replacing the variable loop of E. coli tRNAAla with the longer variable loop of M. tuberculosis tRNASer enables MenT3 to incorporate CMPs into the chimeric tRNAAla. The N-terminal positively charged region of MenT3 is required for CMP incorporation into tRNASer. A docking model of tRNA onto MenT3 suggests that an interaction between the N-terminal region and the longer variable loop of tRNASer facilitates tRNA substrate selection.
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Affiliation(s)
- Jun Liu
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Yuka Yashiro
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Yuriko Sakaguchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kozo Tomita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
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13
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Bustamante P, Ramos-Corominas MN, Martinez-Medina M. Contribution of Toxin-Antitoxin Systems to Adherent-Invasive E. coli Pathogenesis. Microorganisms 2024; 12:1158. [PMID: 38930540 PMCID: PMC11205521 DOI: 10.3390/microorganisms12061158] [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: 05/10/2024] [Revised: 05/24/2024] [Accepted: 06/05/2024] [Indexed: 06/28/2024] Open
Abstract
Pathobionts have been implicated in various chronic diseases, including Crohn's disease (CD), a multifactorial chronic inflammatory condition that primarily affects the gastrointestinal tract, causing inflammation and damage to the digestive system. While the exact cause of CD remains unclear, adherent-invasive Escherichia coli (AIEC) strains have emerged as key contributors to its pathogenesis. AIEC are characterized by their ability to adhere to and invade intestinal epithelial cells and survive and replicate inside macrophages. However, the mechanisms underlying the virulence and persistence of AIEC within their host remain the subject of intensive research. Toxin-antitoxin systems (TAs) play a potential role in AIEC pathogenesis and may be therapeutic targets. These systems generally consist of two components: a toxin harmful to the cell and an antitoxin that neutralizes the toxin's effects. They contribute to bacterial survival in adverse conditions and regulate bacterial growth and behavior, affecting various cellular processes in bacterial pathogens. This review focuses on the current information available to determine the roles of TAs in the pathogenicity of AIEC. Their contribution to the AIEC stress response, biofilm formation, phage inhibition, the maintenance of mobile genetic elements, and host lifestyles is discussed.
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Affiliation(s)
- Paula Bustamante
- Molecular and Cellular Microbiology Laboratory, Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago 8910060, Chile
| | - María Núria Ramos-Corominas
- Microbiology of Intestinal Diseases, Biology Department, Universitat de Girona, 17003 Girona, Spain; (M.N.R.-C.); (M.M.-M.)
| | - Margarita Martinez-Medina
- Microbiology of Intestinal Diseases, Biology Department, Universitat de Girona, 17003 Girona, Spain; (M.N.R.-C.); (M.M.-M.)
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14
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Sandhu AK, Fischer BR, Subramanian S, Hoppe AD, Brözel VS. Self-growth suppression in Bradyrhizobium diazoefficiens is caused by a diffusible antagonist. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.01.596975. [PMID: 38853965 PMCID: PMC11160724 DOI: 10.1101/2024.06.01.596975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Microbes in soil navigate interactions by recognizing kin, forming social groups, exhibiting antagonistic behavior, and engaging in competitive kin rivalry. Here, we investigated a novel phenomenon of self-growth suppression (sibling rivalry) observed in Bradyrhizobium diazoefficiens USDA 110. Swimming colonies of USDA 110 developed a distinct demarcation line and inter-colony zone when inoculated adjacent to each other. In addition to self, USDA 110 suppressed growth of other Bradyrhizobium strains and several other soil bacteria. We demonstrated that the phenomenon of sibling rivalry is due to growth suppression but not cell death. The cells in the inter-colony zone were culturable but have reduced respiratory activity, ATP levels and motility. The observed growth suppression was due to the presence of a diffusible effector compound. This effector was labile, preventing extraction, and identification, but it is unlikely a protein or a strong acid or base. This counterintuitive phenomenon of self-growth suppression suggests a strategic adaptation for conserving energy and resources in competitive soil environments. Bradyrhizobium's utilization of antagonism including self-growth suppression likely provides a competitive advantage for long-term success in soil ecosystems.
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Affiliation(s)
- Armaan Kaur Sandhu
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57006
| | - Brady R. Fischer
- Department of Chemistry, Biochemistry and Physics, South Dakota State University, Brookings, SD 57006
| | - Senthil Subramanian
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57006
| | - Adam D. Hoppe
- Department of Chemistry, Biochemistry and Physics, South Dakota State University, Brookings, SD 57006
| | - Volker S. Brözel
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57006
- Department of Biochemistry, Genetics and Microbiology; Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
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15
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Oberhofer G, Johnson ML, Ivy T, Antoshechkin I, Hay BA. Cleave and Rescue gamete killers create conditions for gene drive in plants. NATURE PLANTS 2024; 10:936-953. [PMID: 38886522 DOI: 10.1038/s41477-024-01701-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 04/16/2024] [Indexed: 06/20/2024]
Abstract
Gene drive elements promote the spread of linked traits and can be used to change the composition or fate of wild populations. Cleave and Rescue (ClvR) drive elements sit at a fixed chromosomal position and include a DNA sequence-modifying enzyme such as Cas9/gRNAs that disrupts endogenous versions of an essential gene and a recoded version of the essential gene resistant to cleavage. ClvR spreads by creating conditions in which those lacking ClvR die because they lack functional versions of the essential gene. Here we demonstrate the essential features of the ClvR gene drive in the plant Arabidopsis thaliana through killing of gametes that fail to inherit a ClvR that targets the essential gene YKT61. Resistant alleles, which can slow or prevent drive, were not observed. Modelling shows plant ClvRs are robust to certain failure modes and can be used to rapidly drive population modification or suppression. Possible applications are discussed.
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Affiliation(s)
- Georg Oberhofer
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Michelle L Johnson
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Tobin Ivy
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Igor Antoshechkin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Bruce A Hay
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
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16
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Eun HJ, Lee SY, Lee KY. DNA binding reveals hidden interdomain allostery of a MazE antitoxin from Mycobacterium tuberculosis. Biochem Biophys Res Commun 2024; 710:149898. [PMID: 38598903 DOI: 10.1016/j.bbrc.2024.149898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Accepted: 04/04/2024] [Indexed: 04/12/2024]
Abstract
Type II toxin-antitoxin (TA) systems are ubiquitously distributed genetic elements in prokaryotes and are crucial for cell maintenance and survival under environmental stresses. The antitoxin is a modular protein consisting of the disordered C-terminal region that physically contacts and neutralizes the cognate toxin and the well-folded N-terminal DNA binding domain responsible for autorepression of TA transcription. However, how the two functional domains communicate is largely unknown. Herein, we determined the crystal structure of the N-terminal domain of the type II antitoxin MazE-mt10 from Mycobacterium tuberculosis, revealing a homodimer of the ribbon-helix-helix (RHH) fold with distinct DNA binding specificity. NMR studies demonstrated that full-length MazE-mt10 forms the helical and coiled states in equilibrium within the C-terminal region, and that helical propensity is allosterically enhanced by the N-terminal binding to the cognate operator DNA. This coil-to-helix transition may promote toxin binding/neutralization of MazE-mt10 and further stabilize the TA-DNA transcription repressor. This is supported by many crystal structures of type II TA complexes in which antitoxins form an α-helical structure at the TA interface. The hidden helical state of free MazE-mt10 in solution, favored by DNA binding, adds a new dimension to the regulatory mechanism of type II TA systems. Furthermore, complementary approaches using X-ray crystallography and NMR allow us to study the allosteric interdomain interplay of many other full-length antitoxins of type II TA systems.
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Affiliation(s)
- Hyun-Jong Eun
- The Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Soo-Yeon Lee
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon-si, 11160, Gyeonggi-Do, Republic of Korea
| | - Ki-Young Lee
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon-si, 11160, Gyeonggi-Do, Republic of Korea.
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17
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Liu X, Wang P, Yuan N, Zhai Y, Yang Y, Hao M, Zhang M, Zhou D, Liu W, Jin Y, Wang A. The (p)ppGpp synthetase Rsh promotes rifampicin tolerant persister cell formation in Brucella abortus by regulating the type II toxin-antitoxin module mbcTA. Front Microbiol 2024; 15:1395504. [PMID: 38841069 PMCID: PMC11150624 DOI: 10.3389/fmicb.2024.1395504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 05/01/2024] [Indexed: 06/07/2024] Open
Abstract
Persister cells are transiently tolerant to antibiotics and are associated with recalcitrant chronic infections due to recolonization of host cells after antibiotic removal. Brucella spp. are facultative pathogens that establish intracellular infection cycles in host cells which results in chronic persistent infections. Brucella abortus forms multi-drug persister cells which are promoted by the (p)ppGpp synthetase Rsh during rifampicin exposure. Here, we confirmed that Rsh promoted persister cells formation in B. abortus stationary phase treated with rifampicin and enrofloxacin. Deletion of the gene for Rsh decreased persister cells level in the presence of these drugs in different growth phases. However, persister cells formation by deletion strain varied in different growth phases in the presence of other antibiotics. Rsh also was involved in persister cells formation during rifampicin treatment under certain stress conditions, including acidic conditions, exposure to PBS, and heat stress. Moreover, Rsh impacted persister cell levels during rifampicin or enrofloxacin treatment in RAW264.7 macrophages. Certain typeIItoxin-antitoxin modules were upregulated under various stress conditions in B. abortus. We established that Rsh positively regulated the type II toxin-antitoxin mbcTA. Moreover, rifampicin-tolerant persister cells formation was elevated and ATP levels were decreased when mbcTA promoter was overexpressed in Rsh deletion background in stationary phase. Our results establish that (p)ppGpp synthetase Rsh plays a key role in B. abortus persistence and may serve as a potent novel target in combination with rifampicin in the development of new therapeutic approaches and prevention strategies to treat chronic infections of Brucella.
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Affiliation(s)
- Xiaofang Liu
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Pingping Wang
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Ningqiu Yuan
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Yunyi Zhai
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Yuanhao Yang
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Mingyue Hao
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Mingxing Zhang
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Dong Zhou
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Wei Liu
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Yaping Jin
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Aihua Wang
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
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18
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Schmid N, Brandt D, Walasek C, Rolland C, Wittmann J, Fischer D, Müsken M, Kalinowski J, Thormann K. An autonomous plasmid as an inovirus phage satellite. Appl Environ Microbiol 2024; 90:e0024624. [PMID: 38597658 PMCID: PMC11107163 DOI: 10.1128/aem.00246-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 03/20/2024] [Indexed: 04/11/2024] Open
Abstract
Bacterial viruses (phages) are potent agents of lateral gene transfer and thus are important drivers of evolution. A group of mobile genetic elements, referred to as phage satellites, exploits phages to disseminate their own genetic material. Here, we isolated a novel member of the family Inoviridae, Shewanella phage Dolos, along with an autonomously replicating plasmid, pDolos. Dolos causes a chronic infection in its host Shewanella oneidensis by phage production with only minor effects on the host cell proliferation. When present, plasmid pDolos hijacks Dolos functions to be predominantly packaged into phage virions and released into the environment and, thus, acts as a phage satellite. pDolos can disseminate further genetic material encoding, e.g., resistances or fluorophores to host cells sensitive to Dolos infection. Given the rather simple requirements of a plasmid for takeover of an inovirus and the wide distribution of phages of this group, we speculate that similar phage-satellite systems are common among bacteria.IMPORTANCEPhage satellites are mobile genetic elements, which hijack phages to be transferred to other host cells. The vast majority of these phage satellites integrate within the host's chromosome, and they all carry remaining phage genes. Here, we identified a novel phage satellite, pDolos, which uses an inovirus for dissemination. pDolos (i) remains as an autonomously replicating plasmid within its host, (ii) does not carry recognizable phage genes, and (iii) is smaller than any other phage satellites identified so far. Thus, pDolos is the first member of a new class of phage satellites, which resemble natural versions of phagemids.
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Affiliation(s)
- Nicole Schmid
- Institute for Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - David Brandt
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Claudia Walasek
- Institute for Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Clara Rolland
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany
| | - Johannes Wittmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany
| | - Dorian Fischer
- Institute for Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Mathias Müsken
- Central Facility for Microscopy, Helmholtz Centre for Infection Research GmbH, Braunschweig, Germany
| | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Kai Thormann
- Institute for Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
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19
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Shore SFH, Leinberger FH, Fozo EM, Berghoff BA. Type I toxin-antitoxin systems in bacteria: from regulation to biological functions. EcoSal Plus 2024:eesp00252022. [PMID: 38767346 DOI: 10.1128/ecosalplus.esp-0025-2022] [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: 09/29/2023] [Accepted: 04/11/2024] [Indexed: 05/22/2024]
Abstract
Toxin-antitoxin systems are ubiquitous in the prokaryotic world and widely distributed among chromosomes and mobile genetic elements. Several different toxin-antitoxin system types exist, but what they all have in common is that toxin activity is prevented by the cognate antitoxin. In type I toxin-antitoxin systems, toxin production is controlled by an RNA antitoxin and by structural features inherent to the toxin messenger RNA. Most type I toxins are small membrane proteins that display a variety of cellular effects. While originally discovered as modules that stabilize plasmids, chromosomal type I toxin-antitoxin systems may also stabilize prophages, or serve important functions upon certain stress conditions and contribute to population-wide survival strategies. Here, we will describe the intricate RNA-based regulation of type I toxin-antitoxin systems and discuss their potential biological functions.
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Affiliation(s)
- Selene F H Shore
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Florian H Leinberger
- Institute for Microbiology and Molecular Biology, Justus-Liebig University, Giessen, Germany
| | - Elizabeth M Fozo
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Bork A Berghoff
- Institute for Microbiology and Molecular Biology, Justus-Liebig University, Giessen, Germany
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20
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Ralhan K, Iyer KA, Diaz LL, Bird R, Maind A, Zhou QA. Navigating Antibacterial Frontiers: A Panoramic Exploration of Antibacterial Landscapes, Resistance Mechanisms, and Emerging Therapeutic Strategies. ACS Infect Dis 2024; 10:1483-1519. [PMID: 38691668 PMCID: PMC11091902 DOI: 10.1021/acsinfecdis.4c00115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Revised: 04/11/2024] [Accepted: 04/15/2024] [Indexed: 05/03/2024]
Abstract
The development of effective antibacterial solutions has become paramount in maintaining global health in this era of increasing bacterial threats and rampant antibiotic resistance. Traditional antibiotics have played a significant role in combating bacterial infections throughout history. However, the emergence of novel resistant strains necessitates constant innovation in antibacterial research. We have analyzed the data on antibacterials from the CAS Content Collection, the largest human-curated collection of published scientific knowledge, which has proven valuable for quantitative analysis of global scientific knowledge. Our analysis focuses on mining the CAS Content Collection data for recent publications (since 2012). This article aims to explore the intricate landscape of antibacterial research while reviewing the advancement from traditional antibiotics to novel and emerging antibacterial strategies. By delving into the resistance mechanisms, this paper highlights the need to find alternate strategies to address the growing concern.
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Affiliation(s)
| | | | - Leilani Lotti Diaz
- CAS,
A Division of the American Chemical Society, Columbus, Ohio 43210, United States
| | - Robert Bird
- CAS,
A Division of the American Chemical Society, Columbus, Ohio 43210, United States
| | - Ankush Maind
- ACS
International India Pvt. Ltd., Pune 411044, India
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21
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Bhoobalan-Chitty Y, Xu S, Martinez-Alvarez L, Karamycheva S, Makarova KS, Koonin EV, Peng X. Regulatory sequence-based discovery of anti-defense genes in archaeal viruses. Nat Commun 2024; 15:3699. [PMID: 38698035 PMCID: PMC11065993 DOI: 10.1038/s41467-024-48074-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 04/19/2024] [Indexed: 05/05/2024] Open
Abstract
In silico identification of viral anti-CRISPR proteins (Acrs) has relied largely on the guilt-by-association method using known Acrs or anti-CRISPR associated proteins (Acas) as the bait. However, the low number and limited spread of the characterized archaeal Acrs and Aca hinders our ability to identify Acrs using guilt-by-association. Here, based on the observation that the few characterized archaeal Acrs and Aca are transcribed immediately post viral infection, we hypothesize that these genes, and many other unidentified anti-defense genes (ADG), are under the control of conserved regulatory sequences including a strong promoter, which can be used to predict anti-defense genes in archaeal viruses. Using this consensus sequence based method, we identify 354 potential ADGs in 57 archaeal viruses and 6 metagenome-assembled genomes. Experimental validation identified a CRISPR subtype I-A inhibitor and the first virally encoded inhibitor of an archaeal toxin-antitoxin based immune system. We also identify regulatory proteins potentially akin to Acas that can facilitate further identification of ADGs combined with the guilt-by-association approach. These results demonstrate the potential of regulatory sequence analysis for extensive identification of ADGs in viruses of archaea and bacteria.
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Affiliation(s)
| | - Shuanshuan Xu
- Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | | | - Svetlana Karamycheva
- National Center for Biotechnology Information, National Library of Medicine, NIH, Bethesda, MD, USA
| | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, NIH, Bethesda, MD, USA
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, NIH, Bethesda, MD, USA
| | - Xu Peng
- Department of Biology, University of Copenhagen, Copenhagen N, Denmark.
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22
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Ma J, Qian C, Hu Q, Zhang J, Gu G, Liang X, Zhang L. The bacteriome-coupled phage communities continuously contract and shift to orchestrate the traditional rice vinegar fermentation. Food Res Int 2024; 184:114244. [PMID: 38609223 DOI: 10.1016/j.foodres.2024.114244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 03/12/2024] [Accepted: 03/14/2024] [Indexed: 04/14/2024]
Abstract
Amounts of microbiome studies have uncovered the microbial communities of traditional food fermentations, while in which the phageome development with time is poorly understood. Here, we conducted a study to decipher both phageome and bacteriome of the traditional rice vinegar fermentation. The vinegar phageomes showed significant differences in the alpha diversity, network density and clustering coefficient over time. Peduoviridae had the highest relative abundance. Moreover, the phageome negatively correlated to the cognate bacteriome in alpha diversity, and undergone constantly contracting and shifting across the temporal scale. Nevertheless, 257 core virial clusters (VCs) persistently occurred with time whatever the significant impacts imposed by the varied physiochemical properties. Glycoside hydrolase (GH) and glycosyltransferase (GT) families genes displayed the higher abundances across all samples. Intriguingly, diversely structuring of toxin-antitoxin systems (TAs) and CRISPR-Cas arrays were frequently harbored by phage genomes. Their divergent organization and encoding attributes underlie the multiple biological roles in modulation of network and/or contest of phage community as well as bacterial host community. This phageome-wide mapping will fuel the current insights of phage community ecology in other traditional fermented ecosystems that are challenging to decipher.
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Affiliation(s)
- Jiawen Ma
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang Province 310018, China
| | - Chenggong Qian
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang Province 310018, China
| | - Qijie Hu
- Huzhou Institute of Food and Drug Control, Huzhou, Zhejiang Province 313002, China
| | - Jianping Zhang
- Haining Yufeng Brewing Co., Ltd, Haining, Zhejiang Province 314408, China
| | - Guizhang Gu
- Huzhou Institute of Food and Drug Control, Huzhou, Zhejiang Province 313002, China
| | - Xinle Liang
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang Province 310018, China.
| | - Lei Zhang
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, Zhejiang Province 310018, China.
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23
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Decollogny M, Rottenberg S. Persisting cancer cells are different from bacterial persisters. Trends Cancer 2024; 10:393-406. [PMID: 38429144 DOI: 10.1016/j.trecan.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 01/22/2024] [Accepted: 02/02/2024] [Indexed: 03/03/2024]
Abstract
The persistence of drug-sensitive tumors poses a significant challenge in cancer treatment. The concept of bacterial persisters, which are a subpopulation of bacteria that survive lethal antibiotic doses, is frequently used to compare to residual disease in cancer. Here, we explore drug tolerance of cancer cells and bacteria. We highlight the fact that bacteria, in contrast to cancer cells, have been selected for survival at the population level and may therefore possess contingency mechanisms that cancer cells lack. The precise mechanisms of drug-tolerant cancer cells and bacterial persisters are still being investigated. Undoubtedly, by understanding common features as well as differences, we, in the cancer field, can learn from microbiology to find strategies to eradicate persisting cancer cells.
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Affiliation(s)
- Morgane Decollogny
- Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern, Switzerland; Bern Center for Precision Medicine and Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Sven Rottenberg
- Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern, Switzerland; Bern Center for Precision Medicine and Department for BioMedical Research, University of Bern, Bern, Switzerland.
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24
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Quiñonero-Coronel MDM, Devos DP, Garcillán-Barcia MP. Specificities and commonalities of the Planctomycetes plasmidome. Environ Microbiol 2024; 26:e16638. [PMID: 38733104 DOI: 10.1111/1462-2920.16638] [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: 01/25/2024] [Accepted: 04/30/2024] [Indexed: 05/13/2024]
Abstract
Plasmids, despite their critical role in antibiotic resistance and modern biotechnology, are understood in only a few bacterial groups in terms of their natural ecological dynamics. The bacterial phylum Planctomycetes, known for its unique molecular and cellular biology, has a largely unexplored plasmidome. This study offers a thorough exploration of the diversity of natural plasmids within Planctomycetes, which could serve as a foundation for developing various genetic research tools for this phylum. Planctomycetes plasmids encode a broad range of biological functions and appear to have coevolved significantly with their host chromosomes, sharing many homologues. Recent transfer events of insertion sequences between cohabiting chromosomes and plasmids were also observed. Interestingly, 64% of plasmid genes are distantly related to either chromosomally encoded genes or have homologues in plasmids from other bacterial groups. The planctomycetal plasmidome is composed of 36% exclusive proteins. Most planctomycetal plasmids encode a replication initiation protein from the Replication Protein A family near a putative iteron-containing replication origin, as well as active type I partition systems. The identification of one conjugative and three mobilizable plasmids suggests the occurrence of horizontal gene transfer via conjugation within this phylum. This comprehensive description enhances our understanding of the plasmidome of Planctomycetes and its potential implications in antibiotic resistance and biotechnology.
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Affiliation(s)
| | - Damien Paul Devos
- Centro Andaluz de Biología del Desarrollo (CABD, CSIC-Universidad Pablo de Olavide), Sevilla, Spain
| | - M Pilar Garcillán-Barcia
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC, CSIC-Universidad de Cantabria), Cantabria, Spain
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25
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Martínez M, Rizzuto I, Molina R. Knowing Our Enemy in the Antimicrobial Resistance Era: Dissecting the Molecular Basis of Bacterial Defense Systems. Int J Mol Sci 2024; 25:4929. [PMID: 38732145 PMCID: PMC11084316 DOI: 10.3390/ijms25094929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/26/2024] [Accepted: 04/29/2024] [Indexed: 05/13/2024] Open
Abstract
Bacteria and their phage adversaries are engaged in an ongoing arms race, resulting in the development of a broad antiphage arsenal and corresponding viral countermeasures. In recent years, the identification and utilization of CRISPR-Cas systems have driven a renewed interest in discovering and characterizing antiphage mechanisms, revealing a richer diversity than initially anticipated. Currently, these defense systems can be categorized based on the bacteria's strategy associated with the infection cycle stage. Thus, bacterial defense systems can degrade the invading genetic material, trigger an abortive infection, or inhibit genome replication. Understanding the molecular mechanisms of processes related to bacterial immunity has significant implications for phage-based therapies and the development of new biotechnological tools. This review aims to comprehensively cover these processes, with a focus on the most recent discoveries.
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Affiliation(s)
| | | | - Rafael Molina
- Department of Crystallography and Structural Biology, Instituto de Química-Física Blas Cabrera, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain
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26
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Carrera Páez LC, Olivier M, Gambino AS, Poklepovich T, Aguilar AP, Quiroga MP, Centrón D. Sporadic clone Escherichia coli ST615 as a vector and reservoir for dissemination of crucial antimicrobial resistance genes. Front Cell Infect Microbiol 2024; 14:1368622. [PMID: 38741889 PMCID: PMC11089171 DOI: 10.3389/fcimb.2024.1368622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 03/27/2024] [Indexed: 05/16/2024] Open
Abstract
There is scarce information concerning the role of sporadic clones in the dissemination of antimicrobial resistance genes (ARGs) within the nosocomial niche. We confirmed that the clinical Escherichia coli M19736 ST615 strain, one of the first isolates of Latin America that harbors a plasmid with an mcr-1 gene, could receive crucial ARG by transformation and conjugation using as donors critical plasmids that harbor bla CTX-M-15, bla KPC-2, bla NDM-5, bla NDM-1, or aadB genes. Escherichia coli M19736 acquired bla CTX-M-15, bla KPC-2, bla NDM-5, bla NDM-1, and aadB genes, being only blaNDM-1 maintained at 100% on the 10th day of subculture. In addition, when the evolved MDR-E. coli M19736 acquired sequentially bla CTX-M-15 and bla NDM-1 genes, the maintenance pattern of the plasmids changed. In addition, when the evolved XDR-E. coli M19736 acquired in an ulterior step the paadB plasmid, a different pattern of the plasmid's maintenance was found. Interestingly, the evolved E. coli M19736 strains disseminated simultaneously the acquired conjugative plasmids in different combinations though selection was ceftazidime in all cases. Finally, we isolated and characterized the extracellular vesicles (EVs) from the native and evolved XDR-E. coli M19736 strains. Interestingly, EVs from the evolved XDR-E. coli M19736 harbored bla CTX-M-15 though the pDCAG1-CTX-M-15 was previously lost as shown by WGS and experiments, suggesting that EV could be a relevant reservoir of ARG for susceptible bacteria. These results evidenced the genetic plasticity of a sporadic clone of E. coli such as ST615 that could play a relevant transitional link in the clinical dynamics and evolution to multidrug/extensively/pandrug-resistant phenotypes of superbugs within the nosocomial niche by acting simultaneously as a vector and reservoir of multiple ARGs which later could be disseminated.
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Affiliation(s)
- Laura Camila Carrera Páez
- Laboratorio de Investigaciones en Mecanismos de Resistencia a Antibióticos, Instituto de Investigaciones en Microbiología y Parasitología Médica, Facultad de Medicina, Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET), Buenos Aires, Argentina
| | - Martin Olivier
- The Research Institute of the McGill University Health Centre, McGill University, Montréal, QC, Canada
| | - Anahí Samanta Gambino
- Laboratorio de Investigaciones en Mecanismos de Resistencia a Antibióticos, Instituto de Investigaciones en Microbiología y Parasitología Médica, Facultad de Medicina, Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET), Buenos Aires, Argentina
| | - Tomás Poklepovich
- Plataforma de Genómica y Bioinformática, Instituto Nacional de Enfermedades Infecciosas - La Administración Nacional de Laboratorios e Institutos de Salud (INEI-ANLIS) “Dr. Carlos G. Malbrán”, Buenos Aires, Argentina
| | - Andrea Pamela Aguilar
- Laboratorio de Investigaciones en Mecanismos de Resistencia a Antibióticos, Instituto de Investigaciones en Microbiología y Parasitología Médica, Facultad de Medicina, Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET), Buenos Aires, Argentina
| | - María Paula Quiroga
- Laboratorio de Investigaciones en Mecanismos de Resistencia a Antibióticos, Instituto de Investigaciones en Microbiología y Parasitología Médica, Facultad de Medicina, Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET), Buenos Aires, Argentina
| | - Daniela Centrón
- Laboratorio de Investigaciones en Mecanismos de Resistencia a Antibióticos, Instituto de Investigaciones en Microbiología y Parasitología Médica, Facultad de Medicina, Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET), Buenos Aires, Argentina
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27
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Hadži S, Živič Z, Kovačič M, Zavrtanik U, Haesaerts S, Charlier D, Plavec J, Volkov AN, Lah J, Loris R. Fuzzy recognition by the prokaryotic transcription factor HigA2 from Vibrio cholerae. Nat Commun 2024; 15:3105. [PMID: 38600130 PMCID: PMC11006873 DOI: 10.1038/s41467-024-47296-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 03/22/2024] [Indexed: 04/12/2024] Open
Abstract
Disordered protein sequences can exhibit different binding modes, ranging from well-ordered folding-upon-binding to highly dynamic fuzzy binding. The primary function of the intrinsically disordered region of the antitoxin HigA2 from Vibrio cholerae is to neutralize HigB2 toxin through ultra-high-affinity folding-upon-binding interaction. Here, we show that the same intrinsically disordered region can also mediate fuzzy interactions with its operator DNA and, through interplay with the folded helix-turn-helix domain, regulates transcription from the higBA2 operon. NMR, SAXS, ITC and in vivo experiments converge towards a consistent picture where a specific set of residues in the intrinsically disordered region mediate electrostatic and hydrophobic interactions while "hovering" over the DNA operator. Sensitivity of the intrinsically disordered region to scrambling the sequence, position-specific contacts and absence of redundant, multivalent interactions, point towards a more specific type of fuzzy binding. Our work demonstrates how a bacterial regulator achieves dual functionality by utilizing two distinct interaction modes within the same disordered sequence.
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Affiliation(s)
- San Hadži
- Structural Biology Brussels, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
- Centre for Structural Biology, VIB, Pleinlaan 2, 1050, Brussels, Belgium
- Department of Physical Chemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Zala Živič
- Department of Physical Chemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Matic Kovačič
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova, 19, 1000, Ljubljana, Slovenia
| | - Uroš Zavrtanik
- Department of Physical Chemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Sarah Haesaerts
- Structural Biology Brussels, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
- Centre for Structural Biology, VIB, Pleinlaan 2, 1050, Brussels, Belgium
| | - Daniel Charlier
- Research group of Microbiology, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| | - Janez Plavec
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova, 19, 1000, Ljubljana, Slovenia
| | - Alexander N Volkov
- Structural Biology Brussels, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
- Centre for Structural Biology, VIB, Pleinlaan 2, 1050, Brussels, Belgium
- Jean Jeener NMR Centre, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| | - Jurij Lah
- Department of Physical Chemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000, Ljubljana, Slovenia.
| | - Remy Loris
- Structural Biology Brussels, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium.
- Centre for Structural Biology, VIB, Pleinlaan 2, 1050, Brussels, Belgium.
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28
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Gu D, Li A, Zang X, Huang T, Guo Y, Jiao X, Pan Z. Salmonella Enteritidis antitoxin DinJ inhibits NLRP3-dependent canonical inflammasome activation in macrophages. Infect Immun 2024; 92:e0050523. [PMID: 38477589 PMCID: PMC11003228 DOI: 10.1128/iai.00505-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 02/09/2024] [Indexed: 03/14/2024] Open
Abstract
The inflammasome is a pivotal component of the innate immune system, acting as a multiprotein complex that plays an essential role in detecting and responding to microbial infections. Salmonella Enteritidis have evolved multiple mechanisms to regulate inflammasome activation and evade host immune system clearance. Through screening S. Enteritidis C50336ΔfliC transposon mutant library, we found that the insertion mutant of dinJ increased inflammasome activation. In this study, we demonstrated the genetic connection between the antitoxin DinJ and the toxin YafQ in S. Enteritidis, confirming their co-transcription. The deletion mutant ΔfliCΔdinJ increased cell death and IL-1β secretion in J774A.1 cells. Western blotting analysis further showed elevated cleaved Caspase-1 product (p10 subunits) and IL-1β secretion in cells infected with ΔfliCΔdinJ compared to cells infected with ΔfliC. DinJ was found to inhibit canonical inflammasome activation using primary bone marrow-derived macrophages (BMDMs) from Casp-/- C57BL/6 mice. Furthermore, DinJ specifically inhibited NLRP3 inflammasome activation, as demonstrated in BMDMs from Nlrp3-/- and Nlrc4-/- mice. Fluorescence resonance energy transfer (FRET) experiments confirmed the translocation of DinJ into host cells during infection. Finally, we revealed that DinJ could inhibit the secretion of IL-1β and IL-18 in vivo, contributing to S. Enteritidis evading host immune clearance. In summary, our findings provide insights into the role of DinJ in modulating the inflammasome response during S. Enteritidis infection, highlighting its impact on inhibiting inflammasome activation and immune evasion.
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Affiliation(s)
- Dan Gu
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
| | - Ang Li
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
| | - Xirui Zang
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
| | - Tingting Huang
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
| | - Yaxin Guo
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
| | - Xinan Jiao
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
| | - Zhiming Pan
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou University, Yangzhou, Jiangsu, China
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29
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Nagasawa Y, Nakayama M, Kato Y, Ogawa Y, Aribam SD, Tsugami Y, Iwata T, Mikami O, Sugiyama A, Onishi M, Hayashi T, Eguchi M. A novel vaccine strategy using quick and easy conversion of bacterial pathogens to unnatural amino acid-auxotrophic suicide derivatives. Microbiol Spectr 2024; 12:e0355723. [PMID: 38385737 PMCID: PMC10986568 DOI: 10.1128/spectrum.03557-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 01/24/2024] [Indexed: 02/23/2024] Open
Abstract
We propose a novel strategy for quick and easy preparation of suicide live vaccine candidates against bacterial pathogens. This method requires only the transformation of one or more plasmids carrying genes encoding for two types of biological devices, an unnatural amino acid (uAA) incorporation system and toxin-antitoxin systems in which translation of the antitoxins requires the uAA incorporation. Escherichia coli BL21-AI laboratory strains carrying the plasmids were viable in the presence of the uAA, whereas the free toxins killed these strains after the removal of the uAA. The survival time after uAA removal could be controlled by the choice of the uAA incorporation system and toxin-antitoxin systems. Multilayered toxin-antitoxin systems suppressed escape frequency to less than 1 escape per 109 generations in the best case. This conditional suicide system also worked in Salmonella enterica and E. coli clinical isolates. The S. enterica vaccine strains were attenuated with a >105 fold lethal dose. Serum IgG response and protection against the parental pathogenic strain were confirmed. In addition, the live E. coli vaccine strain was significantly more immunogenic and provided greater protection than a formalin-inactivated vaccine. The live E. coli vaccine was not detected after inoculation, presumably because the uAA is not present in the host animals or the natural environment. These results suggest that this strategy provides a novel way to rapidly produce safe and highly immunogenic live bacterial vaccine candidates. IMPORTANCE Live vaccines are the oldest vaccines with a history of more than 200 years. Due to their strong immunogenicity, live vaccines are still an important category of vaccines today. However, the development of live vaccines has been challenging due to the difficulties in achieving a balance between safety and immunogenicity. In recent decades, the frequent emergence of various new and old pathogens at risk of causing pandemics has highlighted the need for rapid vaccine development processes. We have pioneered the use of uAAs to control gene expression and to conditionally kill host bacteria as a biological containment system. This report proposes a quick and easy conversion of bacterial pathogens into live vaccine candidates using this containment system. The balance between safety and immunogenicity can be modulated by the selection of the genetic devices used. Moreover, the uAA-auxotrophy can prevent the vaccine from infecting other individuals or establishing the environment.
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Affiliation(s)
- Yuya Nagasawa
- National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Sapporo, Hokkaido, Japan
| | - Momoko Nakayama
- National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Yusuke Kato
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Yohsuke Ogawa
- National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Sapporo, Hokkaido, Japan
| | - Swarmistha Devi Aribam
- National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Yusaku Tsugami
- National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Sapporo, Hokkaido, Japan
| | - Taketoshi Iwata
- National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
| | - Osamu Mikami
- National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Sapporo, Hokkaido, Japan
| | - Aoi Sugiyama
- National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Sapporo, Hokkaido, Japan
| | - Megumi Onishi
- National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Sapporo, Hokkaido, Japan
| | - Tomohito Hayashi
- National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Sapporo, Hokkaido, Japan
| | - Masahiro Eguchi
- National Institute of Animal Health, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, Japan
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30
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Mayo-Muñoz D, Pinilla-Redondo R, Camara-Wilpert S, Birkholz N, Fineran PC. Inhibitors of bacterial immune systems: discovery, mechanisms and applications. Nat Rev Genet 2024; 25:237-254. [PMID: 38291236 DOI: 10.1038/s41576-023-00676-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2023] [Indexed: 02/01/2024]
Abstract
To contend with the diversity and ubiquity of bacteriophages and other mobile genetic elements, bacteria have developed an arsenal of immune defence mechanisms. Bacterial defences include CRISPR-Cas, restriction-modification and a growing list of mechanistically diverse systems, which constitute the bacterial 'immune system'. As a response, bacteriophages and mobile genetic elements have evolved direct and indirect mechanisms to circumvent or block bacterial defence pathways and ensure successful infection. Recent advances in methodological and computational approaches, as well as the increasing availability of genome sequences, have boosted the discovery of direct inhibitors of bacterial defence systems. In this Review, we discuss methods for the discovery of direct inhibitors, their diverse mechanisms of action and perspectives on their emerging applications in biotechnology and beyond.
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Affiliation(s)
- David Mayo-Muñoz
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Dunedin, New Zealand
| | - Rafael Pinilla-Redondo
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
- Section of Microbiology, University of Copenhagen, Copenhagen, Denmark.
| | | | - Nils Birkholz
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Dunedin, New Zealand
- Bioprotection Aotearoa, University of Otago, Dunedin, New Zealand
| | - Peter C Fineran
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
- Genetics Otago, University of Otago, Dunedin, New Zealand.
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Dunedin, New Zealand.
- Bioprotection Aotearoa, University of Otago, Dunedin, New Zealand.
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31
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Richard E, Darracq B, Littner E, Millot GA, Conte V, Cokelaer T, Engelstädter J, Rocha EPC, Mazel D, Loot C. Belt and braces: Two escape ways to maintain the cassette reservoir of large chromosomal integrons. PLoS Genet 2024; 20:e1011231. [PMID: 38578806 PMCID: PMC11023631 DOI: 10.1371/journal.pgen.1011231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 04/17/2024] [Accepted: 03/19/2024] [Indexed: 04/07/2024] Open
Abstract
Integrons are adaptive devices that capture, stockpile, shuffle and express gene cassettes thereby sampling combinatorial phenotypic diversity. Some integrons called sedentary chromosomal integrons (SCIs) can be massive structures containing hundreds of cassettes. Since most of these cassettes are non-expressed, it is not clear how they remain stable over long evolutionary timescales. Recently, it was found that the experimental inversion of the SCI of Vibrio cholerae led to a dramatic increase of the cassette excision rate associated with a fitness defect. Here, we question the evolutionary sustainability of this apparently counter selected genetic context. Through experimental evolution, we find that the integrase is rapidly inactivated and that the inverted SCI can recover its original orientation by homologous recombination between two insertion sequences (ISs) present in the array. These two outcomes of SCI inversion restore the normal growth and prevent the loss of cassettes, enabling SCIs to retain their roles as reservoirs of functions. These results illustrate a nice interplay between gene orientation, genome rearrangement, bacterial fitness and demonstrate how integrons can benefit from their embedded ISs.
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Affiliation(s)
- Egill Richard
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
- Sorbonne Université, ED515, Paris, France
| | - Baptiste Darracq
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
- Sorbonne Université, ED515, Paris, France
| | - Eloi Littner
- Sorbonne Université, ED515, Paris, France
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, France
- DGA CBRN Defence, Vert-le-Petit, France
| | - Gael A. Millot
- Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics Hub, Paris, France
| | - Valentin Conte
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
| | - Thomas Cokelaer
- Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics Hub, Paris, France
- Institut Pasteur, Université Paris Cité, Plateforme Technologique Biomics, Paris, France
| | - Jan Engelstädter
- School of the Environment, The University of Queensland, Brisbane, Australia
| | - Eduardo P. C. Rocha
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, France
| | - Didier Mazel
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
| | - Céline Loot
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Unité Plasticité du Génome Bactérien, Paris, France
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Gu Q, Zhu X, Yu Y, Jiang T, Pan Z, Ma J, Yao H. Type II and IV toxin-antitoxin systems coordinately stabilize the integrative and conjugative element of the ICESa2603 family conferring multiple drug resistance in Streptococcus suis. PLoS Pathog 2024; 20:e1012169. [PMID: 38640137 PMCID: PMC11062541 DOI: 10.1371/journal.ppat.1012169] [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: 01/17/2024] [Revised: 05/01/2024] [Accepted: 04/02/2024] [Indexed: 04/21/2024] Open
Abstract
Integrative and conjugative elements (ICEs) play a vital role in bacterial evolution by carrying essential genes that confer adaptive functions to the host. Despite their importance, the mechanism underlying the stable inheritance of ICEs, which is necessary for the acquisition of new traits in bacteria, remains poorly understood. Here, we identified SezAT, a type II toxin-antitoxin (TA) system, and AbiE, a type IV TA system encoded within the ICESsuHN105, coordinately promote ICE stabilization and mediate multidrug resistance in Streptococcus suis. Deletion of SezAT or AbiE did not affect the strain's antibiotic susceptibility, but their duple deletion increased susceptibility, mainly mediated by the antitoxins SezA and AbiEi. Further studies have revealed that SezA and AbiEi affect the genetic stability of ICESsuHN105 by moderating the excision and extrachromosomal copy number, consequently affecting the antibiotic resistance conferred by ICE. The DNA-binding proteins AbiEi and SezA, which bind palindromic sequences in the promoter, coordinately modulate ICE excision and extracellular copy number by binding to sequences in the origin-of-transfer (oriT) and the attL sites, respectively. Furthermore, AbiEi negatively regulates the transcription of SezAT by binding directly to its promoter, optimizing the coordinate network of SezAT and AbiE in maintaining ICESsuHN105 stability. Importantly, SezAT and AbiE are widespread and conserved in ICEs harbouring diverse drug-resistance genes, and their coordinated effects in promoting ICE stability and mediating drug resistance may be broadly applicable to other ICEs. Altogether, our study uncovers the TA system's role in maintaining the genetic stability of ICE and offers potential targets for overcoming the dissemination and evolution of drug resistance.
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Affiliation(s)
- Qibing Gu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Xiayu Zhu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Yong Yu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Tao Jiang
- Department of Stomatology, Jinling Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Zihao Pan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Jiale Ma
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Huochun Yao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
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Zhou S, Zhao L, Zuo W, Zheng Y, Zhang P, Sun Y, Wang Y, Du G, Kang Z. Minimizing endogenous cryptic plasmids to construct antibiotic-free expression systems for Escherichia coli Nissle 1917. Synth Syst Biotechnol 2024; 9:165-175. [PMID: 38348398 PMCID: PMC10859263 DOI: 10.1016/j.synbio.2024.01.006] [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: 08/09/2023] [Revised: 12/25/2023] [Accepted: 01/11/2024] [Indexed: 02/15/2024] Open
Abstract
The probiotic bacterium Escherichia coli Nissle 1917 (EcN) holds significant promise for use in clinical and biological industries. However, the reliance on antibiotics to maintain plasmid-borne genes has overshadowed its benefits. In this study, we addressed this issue by engineering the endogenous cryptic plasmids pMUT1 and pMUT2. The non-essential elements were removed to create more stable derivatives pMUT1NR△ and pMUT2HBC△. Synthetic promoters by integrating binding motifs on sigma factors were further constructed and applied for expression of Bacteroides thetaiotaomicron heparinase III and the biosynthesis of ectoine. Compared to traditional antibiotic-dependent expression systems, our newly constructed antibiotic-free expression systems offer considerable advantages for clinical and synthetic biology applications.
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Affiliation(s)
- Siyan Zhou
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Linlin Zhao
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Wenjie Zuo
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Yilin Zheng
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Ping Zhang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Yanan Sun
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Yang Wang
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Guocheng Du
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Zhen Kang
- The Science Center for Future Foods, Jiangnan University, Wuxi, 214122, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
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Girardin Y, Galle M, Vanden Abeele Y, De Greve H, Loris R. Evaluation of different strategies to produce Vibrio cholerae ParE2 toxin. Protein Expr Purif 2024; 215:106403. [PMID: 37977515 DOI: 10.1016/j.pep.2023.106403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/08/2023] [Accepted: 11/12/2023] [Indexed: 11/19/2023]
Abstract
Toxin-antitoxin (TA) systems are small operons that are omnipresent in bacteria and archaea with suggested roles in stabilization of mobile genetic elements, bacteriophage protection, stress response and possibly persister formation. A major bottleneck in the study of TA toxins is the production of sufficient amounts of well-folded, functional protein. Here we examine alternative approaches for obtaining the VcParE2 toxin from Vibrio cholerae. VcParE2 can be successfully produced via bacterial expression in presence of its cognate antitoxin VcParD2, followed by on-column unfolding and refolding. Alternatively, the toxin can be expressed in Spodoptera frugiperda (Sf9) insect cells. The latter requires disruption of the VcparE2 gene via introduction of an insect cell intron. Both methods provide protein with similar structural and functional characteristics.
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Affiliation(s)
- Yana Girardin
- Molecular Recognition Unit, Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium; Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050, Brussels, Belgium
| | - Margot Galle
- Molecular Recognition Unit, Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium; Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050, Brussels, Belgium
| | - Yaël Vanden Abeele
- Molecular Recognition Unit, Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| | - Henri De Greve
- Molecular Recognition Unit, Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| | - Remy Loris
- Molecular Recognition Unit, Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium; Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050, Brussels, Belgium.
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35
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Schmitt DS, Siegel SD, Selle K. Applications of designer phage encoding recombinant gene payloads. Trends Biotechnol 2024; 42:326-338. [PMID: 37833198 DOI: 10.1016/j.tibtech.2023.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 09/17/2023] [Accepted: 09/19/2023] [Indexed: 10/15/2023]
Abstract
Advances in genetic engineering, synthetic biology, and DNA sequencing have transformed the re-emergent therapeutic bacteriophage field. The increasing rate of multidrug resistant (MDR) infections and the speed at which new bacteriophages can be isolated, sequenced, characterized, and engineered has reinvigorated phage therapy and unlocked new applications of phages for modulating bacteria. The methods used to genetically engineer bacteriophages are undergoing significant development, but identification of heterologous gene payloads with desirable activity and determination of their impact on bacteria or human cells in translationally relevant applications remain underexplored areas. Here, we discuss and categorize recombinant gene payloads for their potential outcome on phage-bacteria interactions when genetically engineered into phage genomes for expression in their bacterial hosts.
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Affiliation(s)
- Daniel S Schmitt
- Biomanufacturing Training and Education Center, North Carolina State University, Raleigh, NC, USA
| | - Sara D Siegel
- Biomanufacturing Training and Education Center, North Carolina State University, Raleigh, NC, USA
| | - Kurt Selle
- Biomanufacturing Training and Education Center, North Carolina State University, Raleigh, NC, USA.
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36
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Malone JG, Thompson CMA. Mechanisms of Plasmid Behavioral Manipulation. DNA Cell Biol 2024; 43:105-107. [PMID: 38294780 DOI: 10.1089/dna.2023.0402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024] Open
Affiliation(s)
- Jacob G Malone
- Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
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37
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Beck IN, Arrowsmith TJ, Grobbelaar MJ, Bromley EC, Marles-Wright J, Blower TR. Toxin release by conditional remodelling of ParDE1 from Mycobacterium tuberculosis leads to gyrase inhibition. Nucleic Acids Res 2024; 52:1909-1929. [PMID: 38113275 PMCID: PMC10899793 DOI: 10.1093/nar/gkad1220] [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: 05/02/2023] [Revised: 12/05/2023] [Accepted: 12/12/2023] [Indexed: 12/21/2023] Open
Abstract
Mycobacterium tuberculosis, the causative agent of tuberculosis, is a growing threat to global health, with recent efforts towards its eradication being reversed in the wake of the COVID-19 pandemic. Increasing resistance to gyrase-targeting second-line fluoroquinolone antibiotics indicates the necessity to develop both novel therapeutics and our understanding of M. tuberculosis growth during infection. ParDE toxin-antitoxin systems also target gyrase and are regulated in response to both host-associated and drug-induced stress during infection. Here, we present microbiological, biochemical, structural, and biophysical analyses exploring the ParDE1 and ParDE2 systems of M. tuberculosis H37Rv. The structures reveal conserved modes of toxin-antitoxin recognition, with complex-specific interactions. ParDE1 forms a novel heterohexameric ParDE complex, supported by antitoxin chains taking on two distinct folds. Curiously, ParDE1 exists in solution as a dynamic equilibrium between heterotetrameric and heterohexameric complexes. Conditional remodelling into higher order complexes can be thermally driven in vitro. Remodelling induces toxin release, tracked through concomitant inhibition and poisoning of gyrase activity. Our work aids our understanding of gyrase inhibition, allowing wider exploration of toxin-antitoxin systems as inspiration for potential therapeutic agents.
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Affiliation(s)
- Izaak N Beck
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
| | - Tom J Arrowsmith
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
| | | | | | - Jon Marles-Wright
- Biosciences Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Tim R Blower
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
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38
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Abril AG, Calo-Mata P, Villa TG, Böhme K, Barros-Velázquez J, Sánchez-Pérez Á, Pazos M, Carrera M. High-Resolution Comparative and Quantitative Proteomics of Biogenic-Amine-Producing Bacteria and Virulence Factors Present in Seafood. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:4448-4463. [PMID: 38364257 PMCID: PMC10906483 DOI: 10.1021/acs.jafc.3c06607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/27/2023] [Accepted: 12/29/2023] [Indexed: 02/18/2024]
Abstract
The presence of biogenic amines (histamine, tyramine, putrescine, and cadaverine) in seafood is a significant concern for food safety. This review describes for the first time a shotgun quantitative proteomics strategy to evaluate and compare foodborne strains of bacteria that produce biogenic amines in seafoods. This approach recognized 35,621 peptide spectrum matches, belonging to 20,792 peptides, and 4621 proteins. It allowed the determination of functional pathways and the classification of the strains into hierarchical clusters. The study identified a protein-protein interaction network involving 1160 nodes/10,318 edges. Proteins were related to energy pathways, spermidine biosynthesis, and putrescine metabolism. Label-free quantitative proteomics allowed the identification of differentially regulated proteins in specific strains such as putrescine aminotransferase, arginine decarboxylase, and l-histidine-binding protein. Additionally, 123 peptides were characterized as virulence factors and 299 peptide biomarkers were selected to identify bacterial species in fish products. This study presents the most extensive proteomic repository and progress in the science of food biogenic bacteria and could be applied in the food industry for the detection of bacterial contamination that produces histamine and other biogenic amines during food processing/storage.
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Affiliation(s)
- Ana G. Abril
- Department
of Food Technology, Spanish National Research
Council (CSIC), Institute of Marine Research (IIM-CSIC), 36208 Vigo, Spain
- Department
of Microbiology and Parasitology, Faculty
of Pharmacy, University of Santiago de Compostela, 15898 Santiago de Compostela, Spain
| | - Pilar Calo-Mata
- Department
of Analytical Chemistry, Nutrition and Food Science, Food Technology
Division, School of Veterinary Sciences,
University of Santiago de Compostela, Campus Lugo, 27002 Lugo, Spain
| | - Tomás G. Villa
- Department
of Microbiology and Parasitology, Faculty
of Pharmacy, University of Santiago de Compostela, 15898 Santiago de Compostela, Spain
| | - Karola Böhme
- Department
of Analytical Chemistry, Nutrition and Food Science, Food Technology
Division, School of Veterinary Sciences,
University of Santiago de Compostela, Campus Lugo, 27002 Lugo, Spain
| | - Jorge Barros-Velázquez
- Department
of Analytical Chemistry, Nutrition and Food Science, Food Technology
Division, School of Veterinary Sciences,
University of Santiago de Compostela, Campus Lugo, 27002 Lugo, Spain
| | - Ángeles Sánchez-Pérez
- Sydney
School of Veterinary Science, Faculty of Science, University of Sydney, Sydney, NSW 2006, Australia
| | - Manuel Pazos
- Department
of Food Technology, Spanish National Research
Council (CSIC), Institute of Marine Research (IIM-CSIC), 36208 Vigo, Spain
| | - Mónica Carrera
- Department
of Food Technology, Spanish National Research
Council (CSIC), Institute of Marine Research (IIM-CSIC), 36208 Vigo, Spain
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Fraikin N, Van Melderen L. Single-cell evidence for plasmid addiction mediated by toxin-antitoxin systems. Nucleic Acids Res 2024; 52:1847-1859. [PMID: 38224456 PMCID: PMC10899753 DOI: 10.1093/nar/gkae018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/22/2023] [Accepted: 01/03/2024] [Indexed: 01/16/2024] Open
Abstract
Toxin-antitoxin (TA) systems are small selfish genetic modules that increase vertical stability of their replicons. They have long been thought to stabilize plasmids by killing cells that fail to inherit a plasmid copy through a phenomenon called post-segregational killing (PSK) or addiction. While this model has been widely accepted, no direct observation of PSK was reported in the literature. Here, we devised a system that enables visualization of plasmid loss and PSK at the single-cell level using meganuclease-driven plasmid curing. Using the ccd system, we show that cells deprived of a ccd-encoding plasmid show hallmarks of DNA damage, i.e. filamentation and induction of the SOS response. Activation of ccd triggered cell death in most plasmid-free segregants, although some intoxicated cells were able to resume growth, showing that PSK-induced damage can be repaired in a SOS-dependent manner. Damage induced by ccd activates resident lambdoid prophages, which potentiate the killing effect of ccd. The loss of a model plasmid containing TA systems encoding toxins presenting various molecular mechanisms induced different morphological changes, growth arrest and loss of viability. Our experimental setup enables further studies of TA-induced phenotypes and suggests that PSK is a general mechanism for plasmid stabilization by TA systems.
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Affiliation(s)
- Nathan Fraikin
- Bacterial Genetics and Physiology, Department of Molecular Biology, Faculté des Sciences, Université Libre de Bruxelles (ULB), 6041 Gosselies, Belgium
| | - Laurence Van Melderen
- Bacterial Genetics and Physiology, Department of Molecular Biology, Faculté des Sciences, Université Libre de Bruxelles (ULB), 6041 Gosselies, Belgium
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40
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Oberhofer G, Johnson ML, Ivy T, Antoshechkin I, Hay BA. Cleave and Rescue gamete killers create conditions for gene drive in plants. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.13.562303. [PMID: 37873352 PMCID: PMC10592828 DOI: 10.1101/2023.10.13.562303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Gene drive elements promote the spread of linked traits, even when their presence confers a fitness cost to carriers, and can be used to change the composition or fate of wild populations. Cleave and Rescue (ClvR) drive elements sit at a fixed chromosomal position and include a DNA sequence-modifying enzyme such as Cas9/gRNAs (the Cleaver/Toxin) that disrupts endogenous versions of an essential gene, and a recoded version of the essential gene resistant to cleavage (the Rescue/Antidote). ClvR spreads by creating conditions in which those lacking ClvR die because they lack functional versions of the essential gene. We demonstrate the essential features of ClvR gene drive in the plant Arabidopsis thaliana through killing of gametes that fail to inherit a ClvR that targets the essential gene YKT61, whose expression is required in male and female gametes for their survival. Resistant (uncleavable but functional) alleles, which can slow or prevent drive, were not observed. Modeling shows plant ClvRs are likely to be robust to certain failure modes and can be used to rapidly drive population modification or suppression. Possible applications in plant breeding, weed control, and conservation are discussed.
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Affiliation(s)
- Georg Oberhofer
- California Institute of Technology. Division of Biology and Biological Engineering. 1200 East California Boulevard, MC156-29, Pasadena, CA 91125
| | - Michelle L. Johnson
- California Institute of Technology. Division of Biology and Biological Engineering. 1200 East California Boulevard, MC156-29, Pasadena, CA 91125
| | - Tobin Ivy
- California Institute of Technology. Division of Biology and Biological Engineering. 1200 East California Boulevard, MC156-29, Pasadena, CA 91125
| | - Igor Antoshechkin
- California Institute of Technology. Division of Biology and Biological Engineering. 1200 East California Boulevard, MC156-29, Pasadena, CA 91125
| | - Bruce A. Hay
- California Institute of Technology. Division of Biology and Biological Engineering. 1200 East California Boulevard, MC156-29, Pasadena, CA 91125
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Ghoshal M, Bechtel TD, Gibbons JG, McLandsborough L. Transcriptomic analysis using RNA sequencing and phenotypic analysis of Salmonella enterica after acid exposure for different time durations using adaptive laboratory evolution. Front Microbiol 2024; 15:1348063. [PMID: 38476938 PMCID: PMC10929716 DOI: 10.3389/fmicb.2024.1348063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/30/2024] [Indexed: 03/14/2024] Open
Abstract
Introduction This study is the final part of a two-part series that delves into the molecular mechanisms driving adaptive laboratory evolution (ALE) of Salmonella enterica in acid stress. The phenotypic and transcriptomic alterations in the acid-evolved lineages (EL) of Salmonella enterica serovar Enteritidis after 70 days of acid stress exposure were analyzed. Materials and methods The stability of phenotypic changes observed after 70 days in acetic acid was explored after stress removal using a newly developed evolutionary lineage EL5. Additionally, the impact of short-term acid stress on the previously adapted lineage EL4 was also examined. Results The results indicate that the elevated antibiotic minimum inhibitory concentration (MIC) observed after exposure to acetic acid for 70 days was lost when acid stress was removed. This phenomenon was observed against human antibiotics such as meropenem, ciprofloxacin, gentamicin, and streptomycin. The MIC of meropenem in EL4 on day 70 was 0.094 mM, which dropped to 0.032 mM when removed from acetic acid stress after day 70. However, after stress reintroduction, the MIC swiftly elevated, and within 4 days, it returned to 0.094 mM. After 20 more days of adaptation in acetic acid, the meropenem MIC increased to 0.125 mM. The other human antibiotics that were tested exhibited a similar trend. The MIC of acetic acid in EL4 on day 70 was observed to be 35 mM, which remained constant even after the removal of acetic acid stress. Readaptation of EL4 in acetic acid for 20 more days caused the acetic acid MIC to increase to 37 mM. Bacterial whole genome sequencing of EL5 revealed base substitutions in several genes involved in pathogenesis, such as the phoQ and wzc genes. Transcriptomic analysis of EL5 revealed upregulation of virulence, drug resistance, toxin-antitoxin, and iron metabolism genes. Unstable Salmonella small colony variants (SSCV) of S. Enteritidis were also observed in EL5 as compared to the wild-type unevolved S. Enteritidis. Discussion This study presents a comprehensive understanding of the evolution of the phenotypic, genomic, and transcriptomic changes in S. Enteritidis due to prolonged acid exposure through ALE.
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Affiliation(s)
- Mrinalini Ghoshal
- Department of Microbiology, University of Massachusetts, Amherst, MA, United States
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
| | - Tyler D. Bechtel
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
| | - John G. Gibbons
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
| | - Lynne McLandsborough
- Department of Food Science, University of Massachusetts, Amherst, MA, United States
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Ardissone S, Greub G. The Chlamydia-related Waddlia chondrophila encodes functional type II toxin-antitoxin systems. Appl Environ Microbiol 2024; 90:e0068123. [PMID: 38214519 PMCID: PMC10880633 DOI: 10.1128/aem.00681-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 11/13/2023] [Indexed: 01/13/2024] Open
Abstract
Bacterial toxin-antitoxin (TA) systems are widespread in chromosomes and plasmids of free-living microorganisms, but only a few have been identified in obligate intracellular species. We found seven putative type II TA modules in Waddlia chondrophila, a Chlamydia-related species that is able to infect a very broad series of eukaryotic hosts, ranging from protists to mammalian cells. The RNA levels of Waddlia TA systems are significantly upregulated by iron starvation and novobiocin, but they are not affected by antibiotics such as β-lactams and glycopeptides, which suggests different mechanisms underlying stress responses. Five of the identified TA modules, including HigBA1 and MazEF1, encoded on the Waddlia cryptic plasmid, proved to be functional when expressed in a heterologous host. TA systems have been associated with the maintenance of mobile genetic elements, bacterial defense against bacteriophages, and persistence upon exposure to adverse conditions. As their RNA levels are upregulated upon exposure to adverse conditions, Waddlia TA modules may be involved in survival to stress. Moreover, as Waddlia can infect a wide range of hosts including free-living amoebae, TA modules could also represent an innate immunity system to fight against bacteriophages and other microorganisms with which Waddlia has to share its replicative niche.IMPORTANCEThe response to adverse conditions, such as exposure to antibiotics, nutrient starvation and competition with other microorganisms, is essential for the survival of a bacterial population. TA systems are modules composed of two elements, a toxic protein and an antitoxin (protein or RNA) that counteracts the toxin. Although many aspects of TA biological functions still await to be elucidated, TAs have often been implicated in bacterial response to stress, including the response to nutrient starvation, antibiotic treatment and bacteriophage infection. TAs are ubiquitous in free-living bacteria but rare in obligate intracellular species such as chlamydiae. We identified functional TA systems in Waddlia chondrophila, a chlamydial species with a strikingly broad host range compared to other chlamydiae. Our work contributes to understand how obligate intracellular bacteria react to adverse conditions that might arise from competition with other viruses/bacteria for the same replicative niche and would threaten their ability to replicate.
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Affiliation(s)
- Silvia Ardissone
- Institute of Microbiology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Gilbert Greub
- Institute of Microbiology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
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Gerdes K. Diverse genetic contexts of HicA toxin domains propose a role in anti-phage defense. mBio 2024; 15:e0329323. [PMID: 38236063 PMCID: PMC10865869 DOI: 10.1128/mbio.03293-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 12/11/2023] [Indexed: 01/19/2024] Open
Abstract
Toxin-antitoxin (TA) modules are prevalent in prokaryotic genomes, often in substantial numbers. For instance, the Mycobacterium tuberculosis genome alone harbors close to 100 TA modules, half of which belong to a singular type. Traditionally ascribed multiple biological roles, recent insights challenge these notions and instead indicate a predominant function in phage defense. TAs are often located within Defense Islands, genomic regions that encode various defense systems. The analysis of genes within Defense Islands has unveiled a wide array of systems, including TAs that serve in anti-phage defense. Prokaryotic cells are equipped with anti-phage Viperins that, analogous to their mammalian counterparts, inhibit viral RNA transcription. Additionally, bacterial Structural Maintenance of Chromosome (SMC) proteins combat plasmid intrusion by recognizing foreign DNA signatures. This study undertakes a comprehensive bioinformatics analysis of genetic elements encoding the HicA double-stranded RNA-binding domain, complemented by protein structure modeling. The HicA toxin domains are found in at least 14 distinct contexts and thus exhibit a remarkable genetic diversity. Traditional bicistronic TA operons represent eight of these contexts, while four are characterized by monocistronic operons encoding fused HicA domains. Two contexts involve hicA adjacent to genes that encode bacterial Viperins. Notably, genes encoding RelE toxins are also adjacent to Viperin genes in some instances. This configuration hints at a synergistic enhancement of Viperin-mediated anti-phage action by HicA and RelE toxins. The discovery of a HicA domain merged with an SMC domain is compelling, prompting further investigation into its potential roles.IMPORTANCEProkaryotic organisms harbor a multitude of toxin-antitoxin (TA) systems, which have long puzzled scientists as "genes in search for a function." Recent scientific advancements have shed light on the primary role of TAs as anti-phage defense mechanisms. To gain an overview of TAs it is important to analyze their genetic contexts that can give hints on function and guide future experimental inquiries. This article describes a thorough bioinformatics examination of genes encoding the HicA toxin domain, revealing its presence in no fewer than 14 unique genetic arrangements. Some configurations notably align with anti-phage activities, underscoring potential roles in microbial immunity. These insights robustly reinforce the hypothesis that HicA toxins are integral components of the prokaryotic anti-phage defense repertoire. The elucidation of these genetic contexts not only advances our understanding of TAs but also contributes to a paradigm shift in how we perceive their functionality within the microbial world.
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Affiliation(s)
- Kenn Gerdes
- Kenn Gerdes is an independent researcher with the residence, Voldmestergade, Copenhagen, Denmark
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Makarova KS, Zhang C, Wolf YI, Karamycheva S, Whitaker RJ, Koonin EV. Computational analysis of genes with lethal knockout phenotype and prediction of essential genes in archaea. mBio 2024; 15:e0309223. [PMID: 38189270 PMCID: PMC10865827 DOI: 10.1128/mbio.03092-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 11/27/2023] [Indexed: 01/09/2024] Open
Abstract
The identification of microbial genes essential for survival as those with lethal knockout phenotype (LKP) is a common strategy for functional interrogation of genomes. However, interpretation of the LKP is complicated because a substantial fraction of the genes with this phenotype remains poorly functionally characterized. Furthermore, many genes can exhibit LKP not because their products perform essential cellular functions but because their knockout activates the toxicity of other genes (conditionally essential genes). We analyzed the sets of LKP genes for two archaea, Methanococcus maripaludis and Sulfolobus islandicus, using a variety of computational approaches aiming to differentiate between essential and conditionally essential genes and to predict at least a general function for as many of the proteins encoded by these genes as possible. This analysis allowed us to predict the functions of several LKP genes including previously uncharacterized subunit of the GINS protein complex with an essential function in genome replication and of the KEOPS complex that is responsible for an essential tRNA modification as well as GRP protease implicated in protein quality control. Additionally, several novel antitoxins (conditionally essential genes) were predicted, and this prediction was experimentally validated by showing that the deletion of these genes together with the adjacent genes apparently encoding the cognate toxins caused no growth defect. We applied principal component analysis based on sequence and comparative genomic features showing that this approach can separate essential genes from conditionally essential ones and used it to predict essential genes in other archaeal genomes.IMPORTANCEOnly a relatively small fraction of the genes in any bacterium or archaeon is essential for survival as demonstrated by the lethal effect of their disruption. The identification of essential genes and their functions is crucial for understanding fundamental cell biology. However, many of the genes with a lethal knockout phenotype remain poorly functionally characterized, and furthermore, many genes can exhibit this phenotype not because their products perform essential cellular functions but because their knockout activates the toxicity of other genes. We applied state-of-the-art computational methods to predict the functions of a number of uncharacterized genes with the lethal knockout phenotype in two archaeal species and developed a computational approach to predict genes involved in essential functions. These findings advance the current understanding of key functionalities of archaeal cells.
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Affiliation(s)
- Kira S. Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Changyi Zhang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yuri I. Wolf
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Svetlana Karamycheva
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Rachel J. Whitaker
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
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45
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Gao SM, Fei HL, Li Q, Lan LY, Huang LN, Fan PF. Eco-evolutionary dynamics of gut phageome in wild gibbons (Hoolock tianxing) with seasonal diet variations. Nat Commun 2024; 15:1254. [PMID: 38341424 PMCID: PMC10858875 DOI: 10.1038/s41467-024-45663-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 01/30/2024] [Indexed: 02/12/2024] Open
Abstract
It has been extensively studied that the gut microbiome provides animals flexibility to adapt to food variability. Yet, how gut phageome responds to diet variation of wild animals remains unexplored. Here, we analyze the eco-evolutionary dynamics of gut phageome in six wild gibbons (Hoolock tianxing) by collecting individually-resolved fresh fecal samples and parallel feeding behavior data for 15 consecutive months. Application of complementary viral and microbial metagenomics recovers 39,198 virulent and temperate phage genomes from the feces. Hierarchical cluster analyses show remarkable seasonal diet variations in gibbons. From high-fruit to high-leaf feeding period, the abundances of phage populations are seasonally fluctuated, especially driven by the increased abundance of virulent phages that kill the Lachnospiraceae hosts, and a decreased abundance of temperate phages that piggyback the Bacteroidaceae hosts. Functional profiling reveals an enrichment through horizontal gene transfers of toxin-antitoxin genes on temperate phage genomes in high-leaf season, potentially conferring benefits to their prokaryotic hosts. The phage-host ecological dynamics are driven by the coevolutionary processes which select for tail fiber and DNA primase genes on virulent and temperate phage genomes, respectively. Our results highlight complex phageome-microbiome interactions as a key feature of the gibbon gut microbial ecosystem responding to the seasonal diet.
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Affiliation(s)
- Shao-Ming Gao
- School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, PR China
| | - Han-Lan Fei
- School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, PR China
- College of Life Science, China West Normal University, Nanchong, 637002, PR China
| | - Qi Li
- School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, PR China
| | - Li-Ying Lan
- School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, PR China
| | - Li-Nan Huang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, PR China.
| | - Peng-Fei Fan
- School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, PR China.
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46
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Hyun JS, Pun R, Park SJ, Lee BJ. Effect of Divalent Metal Ions on the Ribonuclease Activity of the Toxin Molecule HP0894 from Helicobacter pylori. Life (Basel) 2024; 14:225. [PMID: 38398734 PMCID: PMC10890551 DOI: 10.3390/life14020225] [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: 12/27/2023] [Revised: 01/31/2024] [Accepted: 01/31/2024] [Indexed: 02/25/2024] Open
Abstract
Bacteria and archaea respond and adapt to environmental stress conditions by modulating the toxin-antitoxin (TA) system for survival. Within the bacterium Helicobacter pylori, the protein HP0894 is a key player in the HP0894-HP0895 TA system, in which HP0894 serves as a toxin and HP0895 as an antitoxin. HP0894 has intrinsic ribonuclease (RNase) activity that regulates gene expression and translation, significantly influencing bacterial physiology and survival. This activity is influenced by the presence of metal ions such as Mg2+. In this study, we explore the metal-dependent RNase activity of HP0894. Surprisingly, all tested metal ions lead to a reduction in RNase activity, with zinc ions (Zn2+) causing the most significant decrease. The secondary structure of HP0894 remained largely unaffected by Zn2+ binding, whereas structural rigidity was notably increased, as revealed using CD analysis. NMR characterized the Zn2+ binding, implicating numerous His, Asp, and Glu residues in HP0894. In summary, these results suggest that metal ions play a regulatory role in the RNase activity of HP0894, contributing to maintaining the toxin molecule in an inactive state under normal conditions.
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Affiliation(s)
- Ja-Shil Hyun
- Gachon Institute of Pharmaceutical Sciences, College of Pharmacy, Gachon University, 191 Hambakmoero, Yeonsu-gu, Incheon 21936, Republic of Korea
| | - Rabin Pun
- Gachon Institute of Pharmaceutical Sciences, College of Pharmacy, Gachon University, 191 Hambakmoero, Yeonsu-gu, Incheon 21936, Republic of Korea
| | - Sung Jean Park
- Gachon Institute of Pharmaceutical Sciences, College of Pharmacy, Gachon University, 191 Hambakmoero, Yeonsu-gu, Incheon 21936, Republic of Korea
| | - Bong-Jin Lee
- College of Pharmacy, Ajou University, 206 World Cup-ro, Yeongtong-gu, Suwon 16499, Republic of Korea
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Jiang YN, Tamiya-Ishitsuka H, Aoi R, Okabe T, Yokota A, Noda N. MazEF Homologs in Symbiobacterium thermophilum Exhibit Cross-Neutralization with Non-Cognate MazEFs. Toxins (Basel) 2024; 16:81. [PMID: 38393159 PMCID: PMC10893535 DOI: 10.3390/toxins16020081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/25/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Toxin-antitoxin systems are preserved by nearly every prokaryote. The type II toxin MazF acts as a sequence-specific endoribonuclease, cleaving ribonucleotides at specific sequences that vary from three to seven bases, as has been reported in different host organisms to date. The present study characterized the MazEF module (MazEF-sth) conserved in the Symbiobacterium thermophilum IAM14863 strain, a Gram-negative syntrophic bacterium that can be supported by co-culture with multiple bacteria, including Bacillus subtilis. Based on a method combining massive parallel sequencing and the fluorometric assay, MazF-sth was determined to cleave ribonucleotides at the UACAUA motif, which is markedly similar to the motifs recognized by MazF from B. subtilis (MazF-bs), and by several MazFs from Gram-positive bacteria. MazF-sth, with mutations at conserved amino acid residues Arg29 and Thr52, lost most ribonuclease activity, indicating that these residues that are crucial for MazF-bs also play significant roles in MazF-sth catalysis. Further, cross-neutralization between MazF-sth and the non-cognate MazE-bs was discovered, and herein, the neutralization mechanism is discussed based on a protein-structure simulation via AlphaFold2 and multiple sequence alignment. The conflict between the high homology shared by these MazF amino acid sequences and the few genetic correlations among their host organisms may provide evidence of horizontal gene transfer.
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Affiliation(s)
- Yu-Nong Jiang
- Master’s/Doctoral Program in Life Science Innovation, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba 305-8572, Ibaraki, Japan
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566, Ibaraki, Japan
| | - Hiroko Tamiya-Ishitsuka
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566, Ibaraki, Japan
| | - Rie Aoi
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566, Ibaraki, Japan
- Department of Life Science and Medical Bioscience, Waseda University, Shinjuku-ku 162-8480, Tokyo, Japan
| | - Takuma Okabe
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566, Ibaraki, Japan
- Department of Life Science and Medical Bioscience, Waseda University, Shinjuku-ku 162-8480, Tokyo, Japan
| | - Akiko Yokota
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566, Ibaraki, Japan
| | - Naohiro Noda
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566, Ibaraki, Japan
- Department of Life Science and Medical Bioscience, Waseda University, Shinjuku-ku 162-8480, Tokyo, Japan
- Master’s/Doctoral Program in Life Science Innovation, School of Integrative and Global Majors, University of Tsukuba, Tsukuba 305-8572, Ibaraki, Japan
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48
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Bonabal S, Darfeuille F. Preventing toxicity in toxin-antitoxin systems: An overview of regulatory mechanisms. Biochimie 2024; 217:95-105. [PMID: 37473832 DOI: 10.1016/j.biochi.2023.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/13/2023] [Accepted: 07/17/2023] [Indexed: 07/22/2023]
Abstract
Toxin-antitoxin systems (TAs) are generally two-component genetic modules present in almost every prokaryotic genome. The production of the free and active toxin is able to disrupt key cellular processes leading to the growth inhibition or death of its host organism in absence of its cognate antitoxin. The functions attributed to TAs rely on this lethal phenotype ranging from mobile genetic elements stabilization to phage defense. Their abundance in prokaryotic genomes as well as their lethal potential make them attractive targets for new antibacterial strategies. The hijacking of TAs requires a deep understanding of their regulation to be able to design such approach. In this review, we summarize the accumulated knowledge on how bacteria cope with these toxic genes in their genome. The characterized TAs can be grouped based on the way they prevent toxicity. Some systems rely on a tight control of the expression to prevent the production of the toxin while others control the activity of the toxin at the post-translational level.
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Affiliation(s)
- Simon Bonabal
- University of Bordeaux, INSERM U1212, CNRS UMR 5320, ARNA Laboratory, F-33000, Bordeaux, France
| | - Fabien Darfeuille
- University of Bordeaux, INSERM U1212, CNRS UMR 5320, ARNA Laboratory, F-33000, Bordeaux, France.
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49
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Hammer TJ. Why do hosts malfunction without microbes? Missing benefits versus evolutionary addiction. Trends Microbiol 2024; 32:132-141. [PMID: 37652785 DOI: 10.1016/j.tim.2023.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 09/02/2023]
Abstract
Microbes are widely recognized to be vital to host health. This new consensus rests, in part, on experiments showing how hosts malfunction when microbes are removed. More and more microbial dependencies are being discovered, even in fundamental processes such as development, immunity, physiology, and behavior. But why do they exist? The default explanation is that microbes are beneficial; when hosts lose microbes, they also lose benefits. Here I call attention to evolutionary addiction, whereby a host trait evolves a need for microbes without having been improved by them. Evolutionary addiction should be considered when interpreting microbe-removal experiments, as it is a distinct and potentially common process. Further, it may have unique implications for the evolution and stability of host-microbe interactions.
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Affiliation(s)
- Tobin J Hammer
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA, USA.
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50
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Ruan S, Tu CH, Bourne CR. Friend or Foe: Protein Inhibitors of DNA Gyrase. BIOLOGY 2024; 13:84. [PMID: 38392303 PMCID: PMC10886550 DOI: 10.3390/biology13020084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/20/2024] [Accepted: 01/26/2024] [Indexed: 02/24/2024]
Abstract
DNA gyrase is essential for the successful replication of circular chromosomes, such as those found in most bacterial species, by relieving topological stressors associated with unwinding the double-stranded genetic material. This critical central role makes gyrase a valued target for antibacterial approaches, as exemplified by the highly successful fluoroquinolone class of antibiotics. It is reasonable that the activity of gyrase could be intrinsically regulated within cells, thereby helping to coordinate DNA replication with doubling times. Numerous proteins have been identified to exert inhibitory effects on DNA gyrase, although at lower doses, it can appear readily reversible and therefore may have regulatory value. Some of these, such as the small protein toxins found in plasmid-borne addiction modules, can promote cell death by inducing damage to DNA, resulting in an analogous outcome as quinolone antibiotics. Others, however, appear to transiently impact gyrase in a readily reversible and non-damaging mechanism, such as the plasmid-derived Qnr family of DNA-mimetic proteins. The current review examines the origins and known activities of protein inhibitors of gyrase and highlights opportunities to further exert control over bacterial growth by targeting this validated antibacterial target with novel molecular mechanisms. Furthermore, we are gaining new insights into fundamental regulatory strategies of gyrase that may prove important for understanding diverse growth strategies among different bacteria.
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Affiliation(s)
- Shengfeng Ruan
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA
| | - Chih-Han Tu
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA
| | - Christina R Bourne
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA
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