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Chapartegui-González I, Stockton JL, Bowser S, Badten AJ, Torres AG. Unraveling the role of toxin-antitoxin systems in Burkholderia pseudomallei: exploring bacterial pathogenesis and interactions within the HigBA families. Microbiol Spectr 2024; 12:e0074824. [PMID: 38916327 PMCID: PMC11302019 DOI: 10.1128/spectrum.00748-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Accepted: 05/28/2024] [Indexed: 06/26/2024] Open
Abstract
Burkholderia pseudomallei (Bpm) is a Gram-negative intracellular pathogen that causes melioidosis in humans, a neglected, underreported, and lethal disease that can reach a fatal outcome in over 50% of the cases. It can produce both acute and chronic infections, the latter being particularly challenging to eliminate because of the intracellular life cycle of the bacteria and its ability to generate a "persister" dormant state. The molecular mechanism that allows the switch between growing and persister phenotypes is not well understood but it is hypothesized to be due at least in part to the participation of toxin-antitoxin (TA) systems. We have previously studied the link between one of those systems (defined as HigBA) with specific expression patterns associated with levofloxacin antibiotic exposure. Through in silico methods, we predicted the presence of another three pairs of genes encoding for additional putative HigBA systems. Therefore, our main goal was to establish which mechanisms are conserved as well as which pathways are specific among different Bpm TA systems from the same family. We hypothesize that the high prevalence, and sometimes even redundancy of these systems in the Bpm chromosomes indicates that they can interact with each other and not function as only individual systems, as it was traditionally thought, and might be playing an undefined role in Bpm lifecycle. Here, we show that both the toxin and the antitoxin of the different systems contribute to bacterial survival and that toxins from the same family can have a cumulative effect under environmental stressful conditions. IMPORTANCE Toxin-antitoxin (TA) systems play a significant role in bacterial persistence, a phenomenon where bacterial cells enter a dormant or slow-growing state to survive adverse conditions such as nutrient deprivation, antibiotic exposure, or host immune responses. By studying TA systems in Burkholderia pseudomallei, we can gain insights into how this pathogen survives and persists in the host environment, contributing to its virulence and ability to cause melioidosis chronic infections.
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Affiliation(s)
| | - Jacob L. Stockton
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Sarah Bowser
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Alexander J. Badten
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Institute for Translational Sciences, University of Texas Medical Branch, Galveston, Texas, USA
| | - Alfredo G. Torres
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
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2
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Gupta N, Yadav M, Singh G, Chaudhary S, Ghosh C, Rathore JS. Decoding the TAome and computational insights into parDE toxin-antitoxin systems in Pseudomonas aeruginosa. Arch Microbiol 2024; 206:360. [PMID: 39066828 DOI: 10.1007/s00203-024-04085-2] [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: 06/04/2024] [Revised: 07/07/2024] [Accepted: 07/17/2024] [Indexed: 07/30/2024]
Abstract
Toxin-antitoxin (TA) modules are widely found in the genomes of pathogenic bacteria. They regulate vital cellular functions like transcription, translation, and DNA replication, and are therefore essential to the survival of bacteria under stress. With a focus on the type II parDE modules, this study thoroughly examines TAome in Pseudomonas aeruginosa, a bacterium well-known for its adaptability and antibiotic resistance. We explored the TAome in three P. aeruginosa strains: ATCC 27,853, PAO1, and PA14, and found 15 type II TAs in ATCC 27,853, 12 in PAO1, and 13 in PA14, with significant variation in the associated mobile genetic elements. Five different parDE homologs were found by further TAome analysis in ATCC 27,853, and their relationships were confirmed by sequence alignments and precise genomic positions. After comparing these ParDE modules' sequences to those of other pathogenic bacteria, it was discovered that they were conserved throughout many taxa, especially Proteobacteria. Nucleic acids were predicted as potential ligands for ParD antitoxins, whereas ParE toxins interacted with a wide range of small molecules, indicating a diverse functional repertoire. The interaction interfaces between ParDE TAs were clarified by protein-protein interaction networks and docking studies, which also highlighted important residues involved in binding. This thorough examination improves our understanding of the diversity, evolutionary dynamics, and functional significance of TA systems in P. aeruginosa, providing insights into their roles in bacterial physiology and pathogenicity.
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Affiliation(s)
- Nomita Gupta
- School of Biotechnology, Gautam Buddha University, Greater Noida, Yamuna Expressway, Greater Noida, 201312, Uttar Pradesh, India
| | - Mohit Yadav
- School of Biotechnology, Gautam Buddha University, Greater Noida, Yamuna Expressway, Greater Noida, 201312, Uttar Pradesh, India
- Department of Molecular Biology and Biotechnology, Tezpur University, Assam, 784028, India
| | - Garima Singh
- School of Biotechnology, Gautam Buddha University, Greater Noida, Yamuna Expressway, Greater Noida, 201312, Uttar Pradesh, India
| | - Shobhi Chaudhary
- School of Biotechnology, Gautam Buddha University, Greater Noida, Yamuna Expressway, Greater Noida, 201312, Uttar Pradesh, India
| | - Chaitali Ghosh
- Department of Zoology, Gargi College, University of Delhi, Siri Fort Road, New Delhi, 110049, India
| | - Jitendra Singh Rathore
- School of Biotechnology, Gautam Buddha University, Greater Noida, Yamuna Expressway, Greater Noida, 201312, Uttar Pradesh, India.
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3
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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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Mishra AK, Thakare RP, Santani BG, Yabaji SM, Dixit SK, Srivastava KK. Unlocking the enigma of phenotypic drug tolerance: Mechanisms and emerging therapeutic strategies. Biochimie 2024; 220:67-83. [PMID: 38168626 DOI: 10.1016/j.biochi.2023.12.009] [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: 10/11/2023] [Revised: 12/09/2023] [Accepted: 12/27/2023] [Indexed: 01/05/2024]
Abstract
In the ongoing battle against antimicrobial resistance, phenotypic drug tolerance poses a formidable challenge. This adaptive ability of microorganisms to withstand drug pressure without genetic alterations further complicating global healthcare challenges. Microbial populations employ an array of persistence mechanisms, including dormancy, biofilm formation, adaptation to intracellular environments, and the adoption of L-forms, to develop drug tolerance. Moreover, molecular mechanisms like toxin-antitoxin modules, oxidative stress responses, energy metabolism, and (p)ppGpp signaling contribute to this phenomenon. Understanding these persistence mechanisms is crucial for predicting drug efficacy, developing strategies for chronic bacterial infections, and exploring innovative therapies for refractory infections. In this comprehensive review, we dissect the intricacies of drug tolerance and persister formation, explore their role in acquired drug resistance, and highlight emerging therapeutic approaches to combat phenotypic drug tolerance. Furthermore, we outline the future landscape of interventions for persistent bacterial infections.
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Affiliation(s)
- Alok K Mishra
- Division of Microbiology, CSIR-Central Drug Research Institute (CDRI), Jankipuram Extension, Lucknow, Uttar Pradesh, 226031, India; Department of Molecular Cell and Cancer Biology, UMass Chan Medical School, Worcester, MA, 01605, USA.
| | - Ritesh P Thakare
- Division of Microbiology, CSIR-Central Drug Research Institute (CDRI), Jankipuram Extension, Lucknow, Uttar Pradesh, 226031, India; Department of Molecular Cell and Cancer Biology, UMass Chan Medical School, Worcester, MA, 01605, USA
| | - Bela G Santani
- Department of Microbiology, Sant Gadge Baba Amravati University (SGBAU), Amravati, Maharashtra, India
| | - Shivraj M Yabaji
- Division of Microbiology, CSIR-Central Drug Research Institute (CDRI), Jankipuram Extension, Lucknow, Uttar Pradesh, 226031, India; National Emerging Infectious Diseases Laboratories (NEIDL), Boston University, Boston, MA, USA
| | - Shivendra K Dixit
- Division of Medicine ICAR-Indian Veterinary Research Institute (IVRI), Izatnagar Bareilly, Uttar Pradesh, 243122, India.
| | - Kishore K Srivastava
- Division of Microbiology, CSIR-Central Drug Research Institute (CDRI), Jankipuram Extension, Lucknow, Uttar Pradesh, 226031, India.
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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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Nielsen MR, Brodersen DE. Structural Variations and Rearrangements in Bacterial Type II Toxin-Antitoxin Systems. Subcell Biochem 2024; 104:245-267. [PMID: 38963490 DOI: 10.1007/978-3-031-58843-3_11] [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] [Indexed: 07/05/2024]
Abstract
Bacteria encode a wide range of survival and immunity systems, including CRISPR-Cas, restriction-modification systems, and toxin-antitoxin systems involved in defence against bacteriophages, as well as survival during challenging growth conditions or exposure to antibiotics. Toxin-antitoxin (TA) systems are small two- or three-gene cassettes consisting of a metabolic regulator (the "toxin") and its associated antidote (the "antitoxin"), which also often functions as a transcriptional regulator. TA systems are widespread in the genomes of pathogens but are also present in commensal bacterial species and on plasmids. For mobile elements such as plasmids, TA systems play a role in maintenance, and increasing evidence now points to roles of chromosomal toxin-antitoxin systems in anti-phage defence. Moreover, the widespread occurrence of toxin-antitoxin systems in the genomes of pathogens has been suggested to relate to survival during host infection as well as in persistence during antibiotic treatment. Upon repeated exposure to antibiotics, TA systems have been shown to acquire point mutations as well as more dramatic rearrangements such as in-frame deletions with potential relevance for bacterial survival and pathogenesis. In this review, we present an overview of the known functional and structural consequences of mutations and rearrangements arising in bacterial toxin-antitoxin systems and discuss their relevance for survival and persistence of pathogenic species.
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Affiliation(s)
| | - Ditlev E Brodersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark.
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7
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Lin JD, Stogios PJ, Abe KT, Wang A, MacPherson J, Skarina T, Gingras AC, Savchenko A, Ensminger AW. Functional diversification despite structural congruence in the HipBST toxin-antitoxin system of Legionella pneumophila. mBio 2023; 14:e0151023. [PMID: 37819088 PMCID: PMC10653801 DOI: 10.1128/mbio.01510-23] [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: 06/16/2023] [Accepted: 08/29/2023] [Indexed: 10/13/2023] Open
Abstract
IMPORTANCE Toxin-antitoxin (TA) systems are parasitic genetic elements found in almost all bacterial genomes. They are exchanged horizontally between cells and are typically poorly conserved across closely related strains and species. Here, we report the characterization of a tripartite TA system in the bacterial pathogen Legionella pneumophila that is highly conserved across Legionella species genomes. This system (denoted HipBSTLp) is a distant homolog of the recently discovered split-HipA system in Escherichia coli (HipBSTEc). We present bioinformatic, molecular, and structural analyses of the divergence between these two systems and the functionality of this newly described TA system family. Furthermore, we provide evidence to refute previous claims that the toxin in this system (HipTLp) possesses bifunctionality as an L. pneumophila virulence protein. Overall, this work expands our understanding of the split-HipA system architecture and illustrates the potential for undiscovered biology in these abundant genetic elements.
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Affiliation(s)
- Jordan D. Lin
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Peter J. Stogios
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Kento T. Abe
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Lunenfeld-Tanenbaum Research Institute, Sinai Health, Toronto, Ontario, Canada
| | - Avril Wang
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - John MacPherson
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Tatiana Skarina
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Anne-Claude Gingras
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Lunenfeld-Tanenbaum Research Institute, Sinai Health, Toronto, Ontario, Canada
| | - Alexei Savchenko
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Center for Structural Genomics of Infectious Diseases (CSGID), University of Calgary, Calgary, Alberta, Canada
| | - Alexander W. Ensminger
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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Pizzolato-Cezar LR, Spira B, Machini MT. Bacterial toxin-antitoxin systems: Novel insights on toxin activation across populations and experimental shortcomings. CURRENT RESEARCH IN MICROBIAL SCIENCES 2023; 5:100204. [PMID: 38024808 PMCID: PMC10643148 DOI: 10.1016/j.crmicr.2023.100204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2023] Open
Abstract
The alarming rise in hard-to-treat bacterial infections is of great concern to human health. Thus, the identification of molecular mechanisms that enable the survival and growth of pathogens is of utmost urgency for the development of more efficient antimicrobial therapies. In challenging environments, such as presence of antibiotics, or during host infection, metabolic adjustments are essential for microorganism survival and competitiveness. Toxin-antitoxin systems (TASs) consisting of a toxin with metabolic modulating activity and a cognate antitoxin that antagonizes that toxin are important elements in the arsenal of bacterial stress defense. However, the exact physiological function of TA systems is highly debatable and with the exception of stabilization of mobile genetic elements and phage inhibition, other proposed biological functions lack a broad consensus. This review aims at gaining new insights into the physiological effects of TASs in bacteria and exploring the experimental shortcomings that lead to discrepant results in TAS research. Distinct control mechanisms ensure that only subsets of cells within isogenic cultures transiently develop moderate levels of toxin activity. As a result, TASs cause phenotypic growth heterogeneity rather than cell stasis in the entire population. It is this feature that allows bacteria to thrive in diverse environments through the creation of subpopulations with different metabolic rates and stress tolerance programs.
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Affiliation(s)
- Luis R. Pizzolato-Cezar
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Beny Spira
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - M. Teresa Machini
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
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Chan WT, Garcillán-Barcia MP, Yeo CC, Espinosa M. Type II bacterial toxin-antitoxins: hypotheses, facts, and the newfound plethora of the PezAT system. FEMS Microbiol Rev 2023; 47:fuad052. [PMID: 37715317 PMCID: PMC10532202 DOI: 10.1093/femsre/fuad052] [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: 06/26/2023] [Revised: 08/24/2023] [Accepted: 09/07/2023] [Indexed: 09/17/2023] Open
Abstract
Toxin-antitoxin (TA) systems are entities found in the prokaryotic genomes, with eight reported types. Type II, the best characterized, is comprised of two genes organized as an operon. Whereas toxins impair growth, the cognate antitoxin neutralizes its activity. TAs appeared to be involved in plasmid maintenance, persistence, virulence, and defence against bacteriophages. Most Type II toxins target the bacterial translational machinery. They seem to be antecessors of Higher Eukaryotes and Prokaryotes Nucleotide-binding (HEPN) RNases, minimal nucleotidyltransferase domains, or CRISPR-Cas systems. A total of four TAs encoded by Streptococcus pneumoniae, RelBE, YefMYoeB, Phd-Doc, and HicAB, belong to HEPN-RNases. The fifth is represented by PezAT/Epsilon-Zeta. PezT/Zeta toxins phosphorylate the peptidoglycan precursors, thereby blocking cell wall synthesis. We explore the body of knowledge (facts) and hypotheses procured for Type II TAs and analyse the data accumulated on the PezAT family. Bioinformatics analyses showed that homologues of PezT/Zeta toxin are abundantly distributed among 14 bacterial phyla mostly in Proteobacteria (48%), Firmicutes (27%), and Actinobacteria (18%), showing the widespread distribution of this TA. The pezAT locus was found to be mainly chromosomally encoded whereas its homologue, the tripartite omega-epsilon-zeta locus, was found mostly on plasmids. We found several orphan pezT/zeta toxins, unaccompanied by a cognate antitoxin.
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Affiliation(s)
- Wai Ting Chan
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, 9, 28040 Madrid, Spain
| | - Maria Pilar Garcillán-Barcia
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-Consejo Superior de Investigaciones Científicas, C/Albert Einstein 22, PCTCAN, 39011 Santander, Spain
| | - Chew Chieng Yeo
- Centre for Research in Infectious Diseases and Biotechnology (CeRIDB), Faculty of Medicine
, Universiti Sultan Zainal Abidin, Jalan Sultan Mahumd, 20400 Kuala Terengganu, Malaysia
| | - Manuel Espinosa
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu, 9, 28040 Madrid, Spain
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Fernández-García L, Wood TK. Phage-Defense Systems Are Unlikely to Cause Cell Suicide. Viruses 2023; 15:1795. [PMID: 37766202 PMCID: PMC10535081 DOI: 10.3390/v15091795] [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: 07/24/2023] [Revised: 08/19/2023] [Accepted: 08/22/2023] [Indexed: 09/29/2023] Open
Abstract
As new phage-defense systems (PDs) are discovered, the overlap between their mechanisms and those of toxin/antitoxin systems (TAs) is becoming clear in that both use similar means to reduce cellular metabolism; for example, both systems have members that deplete energetic compounds (e.g., NAD+, ATP) and deplete nucleic acids, and both have members that inflict membrane damage. Moreover, both TAs and PDs are similar in that rather than altruistically killing the host to limit phage propagation (commonly known as abortive infection), both reduce host metabolism since phages propagate less in slow-growing cells, and slow growth facilitates the interaction of multiple phage-defense systems.
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Affiliation(s)
| | - Thomas K. Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802-4400, USA;
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Xu X, Usher B, Gutierrez C, Barriot R, Arrowsmith TJ, Han X, Redder P, Neyrolles O, Blower TR, Genevaux P. MenT nucleotidyltransferase toxins extend tRNA acceptor stems and can be inhibited by asymmetrical antitoxin binding. Nat Commun 2023; 14:4644. [PMID: 37591829 PMCID: PMC10435456 DOI: 10.1038/s41467-023-40264-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 07/20/2023] [Indexed: 08/19/2023] Open
Abstract
Mycobacterium tuberculosis, the bacterium responsible for human tuberculosis, has a genome encoding a remarkably high number of toxin-antitoxin systems of largely unknown function. We have recently shown that the M. tuberculosis genome encodes four of a widespread, MenAT family of nucleotidyltransferase toxin-antitoxin systems. In this study we characterize MenAT1, using tRNA sequencing to demonstrate MenT1 tRNA modification activity. MenT1 activity is blocked by MenA1, a short protein antitoxin unrelated to the MenA3 kinase. X-ray crystallographic analysis shows blockage of the conserved MenT fold by asymmetric binding of MenA1 across two MenT1 protomers, forming a heterotrimeric toxin-antitoxin complex. Finally, we also demonstrate tRNA modification by toxin MenT4, indicating conserved activity across the MenT family. Our study highlights variation in tRNA target preferences by MenT toxins, selective use of nucleotide substrates, and diverse modes of MenA antitoxin activity.
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Affiliation(s)
- Xibing Xu
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Ben Usher
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Claude Gutierrez
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Roland Barriot
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Tom J Arrowsmith
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK
| | - Xue Han
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Peter Redder
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Olivier Neyrolles
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France
| | - Tim R Blower
- Department of Biosciences, Durham University, South Road, Durham, DH1 3LE, UK.
| | - Pierre Genevaux
- Laboratoire de Microbiologie et Génétique Moléculaires (LMGM), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, Université Toulouse III - Paul Sabatier (UT3), Toulouse, France.
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Boss L, Kędzierska B. Bacterial Toxin-Antitoxin Systems' Cross-Interactions-Implications for Practical Use in Medicine and Biotechnology. Toxins (Basel) 2023; 15:380. [PMID: 37368681 DOI: 10.3390/toxins15060380] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 05/30/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
Toxin-antitoxin (TA) systems are widely present in bacterial genomes. They consist of stable toxins and unstable antitoxins that are classified into distinct groups based on their structure and biological activity. TA systems are mostly related to mobile genetic elements and can be easily acquired through horizontal gene transfer. The ubiquity of different homologous and non-homologous TA systems within a single bacterial genome raises questions about their potential cross-interactions. Unspecific cross-talk between toxins and antitoxins of non-cognate modules may unbalance the ratio of the interacting partners and cause an increase in the free toxin level, which can be deleterious to the cell. Moreover, TA systems can be involved in broadly understood molecular networks as transcriptional regulators of other genes' expression or modulators of cellular mRNA stability. In nature, multiple copies of highly similar or identical TA systems are rather infrequent and probably represent a transition stage during evolution to complete insulation or decay of one of them. Nevertheless, several types of cross-interactions have been described in the literature to date. This implies a question of the possibility and consequences of the TA system cross-interactions, especially in the context of the practical application of the TA-based biotechnological and medical strategies, in which such TAs will be used outside their natural context, will be artificially introduced and induced in the new hosts. Thus, in this review, we discuss the prospective challenges of system cross-talks in the safety and effectiveness of TA system usage.
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Affiliation(s)
- Lidia Boss
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdańsk, 80-309 Gdańsk, Poland
| | - Barbara Kędzierska
- Department of Bacterial Molecular Genetics, Faculty of Biology, University of Gdańsk, 80-309 Gdańsk, Poland
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Bleriot I, Blasco L, Pacios O, Fernández-García L, López M, Ortiz-Cartagena C, Barrio-Pujante A, Fernández-Cuenca F, Pascual Á, Martínez-Martínez L, Oteo-Iglesias J, Tomás M. Proteomic Study of the Interactions between Phages and the Bacterial Host Klebsiella pneumoniae. Microbiol Spectr 2023; 11:e0397422. [PMID: 36877024 PMCID: PMC10100988 DOI: 10.1128/spectrum.03974-22] [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: 10/03/2022] [Accepted: 02/08/2023] [Indexed: 03/07/2023] Open
Abstract
Phages and bacteria have acquired resistance mechanisms for protection. In this context, the aims of the present study were to analyze the proteins isolated from 21 novel lytic phages of Klebsiella pneumoniae in search of defense mechanisms against bacteria and also to determine the infective capacity of the phages. A proteomic study was also conducted to investigate the defense mechanisms of two clinical isolates of K. pneumoniae infected by phages. For this purpose, the 21 lytic phages were sequenced and de novo assembled. The host range was determined in a collection of 47 clinical isolates of K. pneumoniae, revealing the variable infective capacity of the phages. Genome sequencing showed that all of the phages were lytic phages belonging to the order Caudovirales. Phage sequence analysis revealed that the proteins were organized in functional modules within the genome. Although most of the proteins have unknown functions, multiple proteins were associated with defense mechanisms against bacteria, including the restriction-modification system, the toxin-antitoxin system, evasion of DNA degradation, blocking of host restriction and modification, the orphan CRISPR-Cas system, and the anti-CRISPR system. Proteomic study of the phage-host interactions (i.e., between isolates K3574 and K3320, which have intact CRISPR-Cas systems, and phages vB_KpnS-VAC35 and vB_KpnM-VAC36, respectively) revealed the presence of several defense mechanisms against phage infection (prophage, defense/virulence/resistance, oxidative stress and plasmid proteins) in the bacteria, and of the Acr candidate (anti-CRISPR protein) in the phages. IMPORTANCE Researchers, including microbiologists and infectious disease specialists, require more knowledge about the interactions between phages and their bacterial hosts and about their defense mechanisms. In this study, we analyzed the molecular mechanisms of viral and bacterial defense in phages infecting clinical isolates of K. pneumoniae. Viral defense mechanisms included restriction-modification system evasion, the toxin-antitoxin (TA) system, DNA degradation evasion, blocking of host restriction and modification, and resistance to the abortive infection system, anti-CRISPR and CRISPR-Cas systems. Regarding bacterial defense mechanisms, proteomic analysis revealed expression of proteins involved in the prophage (FtsH protease modulator), plasmid (cupin phosphomannose isomerase protein), defense/virulence/resistance (porins, efflux pumps, lipopolysaccharide, pilus elements, quorum network proteins, TA systems, and methyltransferases), oxidative stress mechanisms, and Acr candidates (anti-CRISPR protein). The findings reveal some important molecular mechanisms involved in the phage-host bacterial interactions; however, further study in this field is required to improve the efficacy of phage therapy.
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Affiliation(s)
- Inés Bleriot
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Lucia Blasco
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Olga Pacios
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Laura Fernández-García
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - María López
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Concha Ortiz-Cartagena
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Antonio Barrio-Pujante
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
| | - Felipe Fernández-Cuenca
- Clinical Unit of Infectious Diseases and Microbiology, Hospital Universitario Virgen Macarena, Institute of Biomedicine of Seville (University Hospital Virgen Macarena/CSIC/University of Seville), Seville, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Álvaro Pascual
- Clinical Unit of Infectious Diseases and Microbiology, Hospital Universitario Virgen Macarena, Institute of Biomedicine of Seville (University Hospital Virgen Macarena/CSIC/University of Seville), Seville, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Luis Martínez-Martínez
- Clinical Unit of Microbiology, Reina Sofía University Hospital, Department of Agricultural Chemistry, Edaphology and Microbiology, University of Cordoba, Maimonides Biomedical Research Institute (IMIBIC), Cordoba, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Jesús Oteo-Iglesias
- Reference and Research Laboratory for Antibiotic Resistance and Health Care Infections, National Centre for Microbiology, Institute of Health Carlos III, Majadahonda, Madrid, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - María Tomás
- Microbiology Translational and Multidisciplinary (MicroTM)-Research Institute Biomedical A Coruña (INIBIC) and Microbiology Department of Hospital A Coruña (CHUAC), University of A Coruña (UDC), A Coruña, Spain
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14
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Berne C, Zappa S, Brun YV. eDNA-stimulated cell dispersion from Caulobacter crescentus biofilms upon oxygen limitation is dependent on a toxin-antitoxin system. eLife 2023; 12:80808. [PMID: 36475544 PMCID: PMC9851616 DOI: 10.7554/elife.80808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
In their natural environment, most bacteria preferentially live as complex surface-attached multicellular colonies called biofilms. Biofilms begin with a few cells adhering to a surface, where they multiply to form a mature colony. When conditions deteriorate, cells can leave the biofilm. This dispersion is thought to be an important process that modifies the overall biofilm architecture and that promotes colonization of new environments. In Caulobacter crescentus biofilms, extracellular DNA (eDNA) is released upon cell death and prevents newborn cells from joining the established biofilm. Thus, eDNA promotes the dispersal of newborn cells and the subsequent colonization of new environments. These observations suggest that eDNA is a cue for sensing detrimental environmental conditions in the biofilm. Here, we show that the toxin-antitoxin system (TAS) ParDE4 stimulates cell death in areas of a biofilm with decreased O2 availability. In conditions where O2 availability is low, eDNA concentration is correlated with cell death. Cell dispersal away from biofilms is decreased when parDE4 is deleted, probably due to the lower local eDNA concentration. Expression of parDE4 is positively regulated by O2 and the expression of this operon is decreased in biofilms where O2 availability is low. Thus, a programmed cell death mechanism using an O2-regulated TAS stimulates dispersal away from areas of a biofilm with decreased O2 availability and favors colonization of a new, more hospitable environment.
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Affiliation(s)
- Cecile Berne
- Département de microbiologie, infectiologie et immunologie, Université de MontréalMontréalCanada
| | - Sébastien Zappa
- Département de microbiologie, infectiologie et immunologie, Université de MontréalMontréalCanada
| | - Yves V Brun
- Département de microbiologie, infectiologie et immunologie, Université de MontréalMontréalCanada
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15
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Cui Y, Su X, Wang C, Xu H, Hu D, Wang J, Pei K, Sun M, Zou T. Bacterial MazF/MazE toxin-antitoxin suppresses lytic propagation of arbitrium-containing phages. Cell Rep 2022; 41:111752. [PMID: 36476854 DOI: 10.1016/j.celrep.2022.111752] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 05/18/2022] [Accepted: 11/09/2022] [Indexed: 12/12/2022] Open
Abstract
Temperate phages dynamically switch between lysis and lysogeny in their full life cycle. Some Bacillus-infecting phages utilize a quorum-sensing-like intercellular communication system, the "arbitrium," to mediate lysis-lysogeny decisions. However, whether additional factors participate in the arbitrium signaling pathway remains largely elusive. Here, we find that the arbitrium signal induces the expression of a functionally conserved operon downstream of the arbitrium module in SPbeta-like phages. SPbeta yopM and yopR (as well as phi3T phi3T_93 and phi3T_97) in the operon play roles in suppressing phage lytic propagation and promoting lysogeny, respectively. We further focus on phi3T_93 and demonstrate that it directly binds antitoxin MazE in the host MazF/MazE toxin-antitoxin (TA) module and facilitates the activation of MazF's toxicity, which is required for phage suppression. These findings show events regulated by the arbitrium system and shed light on how the interplay between phages and the host TA module affects phage-host co-survival.
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Affiliation(s)
- Yongqing Cui
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiang Su
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China
| | - Chen Wang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China
| | - Han Xu
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China
| | - Delei Hu
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China
| | - Jing Wang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China
| | - Kai Pei
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China
| | - Ming Sun
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China
| | - Tingting Zou
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China.
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16
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Identification of chromosomal type II toxin–antitoxin system from plant pathogenic Pseudomonas cichorii JBC 1. Mol Cell Toxicol 2022. [DOI: 10.1007/s13273-022-00324-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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17
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Shi X, Zarkan A. Bacterial survivors: evaluating the mechanisms of antibiotic persistence. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 36748698 DOI: 10.1099/mic.0.001266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Bacteria withstand antibiotic onslaughts by employing a variety of strategies, one of which is persistence. Persistence occurs in a bacterial population where a subpopulation of cells (persisters) survives antibiotic treatment and can regrow in a drug-free environment. Persisters may cause the recalcitrance of infectious diseases and can be a stepping stone to antibiotic resistance, so understanding persistence mechanisms is critical for therapeutic applications. However, current understanding of persistence is pervaded by paradoxes that stymie research progress, and many aspects of this cellular state remain elusive. In this review, we summarize the putative persister mechanisms, including toxin-antitoxin modules, quorum sensing, indole signalling and epigenetics, as well as the reasons behind the inconsistent body of evidence. We highlight present limitations in the field and underscore a clinical context that is frequently neglected, in the hope of supporting future researchers in examining clinically important persister mechanisms.
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Affiliation(s)
- Xiaoyi Shi
- Cambridge Centre for International Research, Cambridge CB4 0PZ, UK
| | - Ashraf Zarkan
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK
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18
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Wang C, Niu C, Hidayatullah KM, Xue L, Zhu Z, Niu L. Structural insights into the PrpTA toxin-antitoxin system in Pseudoalteromonas rubra. Front Microbiol 2022; 13:1053255. [PMID: 36504814 PMCID: PMC9731233 DOI: 10.3389/fmicb.2022.1053255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 10/31/2022] [Indexed: 11/27/2022] Open
Abstract
Bacteria could survive stresses by a poorly understood mechanism that contributes to the emergence of bacterial persisters exhibiting multidrug tolerance (MDT). Recently, Pseudoalteromonas rubra prpAT module was found to encode a toxin PrpT and corresponding cognate antidote PrpA. In this study, we first reported multiple individual and complex structures of PrpA and PrpT, which uncovered the high-resolution three-dimensional structure of the PrpT:PrpA2:PrpT heterotetramer with the aid of size exclusion chromatography-multi-angle light scattering experiments (SEC-MALS). PrpT:PrpA2:PrpT is composed of a PrpA homodimer and two PrpT monomers which are relatively isolated from each other and from ParE family. The superposition of antitoxin monomer structures from these structures highlighted the flexible C-terminal domain (CTD). A striking conformational change in the CTDs of PrpA homodimer depolymerized from homotetramer was provoked upon PrpT binding, which accounts for the unique PrpT-PrpARHH mutual interactions and further neutralizes the toxin PrpT. PrpA2-54-form I and II crystal structures both contain a doughnut-shaped hexadecamer formed by eight homodimers organized in a cogwheel-like form via inter-dimer interface dominated by salt bridges and hydrogen bonds. Moreover, PrpA tends to exist in solution as a homodimer other than a homotetramer (SEC-MALS) in the absence of flexible CTD. Multiple multi-dimers, tetramer and hexamer included, of PrpA2-54 mediated by the symmetric homodimer interface and the complicated inter-dimer interface could be observed in the solution. SEC-MALS assays highlighted that phosphate buffer (PB) and the increase in the concentration appear to be favorable for the PrpA2-54 oligomerization in the solution. Taken together with previous research, a model of PrpA2-54 homotetramer in complex with prpAT promoter and the improved mechanism underlying how PrpTA controls the plasmid replication were proposed here.
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Affiliation(s)
- Chenchen Wang
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Chuanying Niu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
- Center for Infection and Immunity, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Khan Muhammad Hidayatullah
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Lu Xue
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
- Center for Infection and Immunity, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Zhongliang Zhu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Liwen Niu
- MOE Key Laboratory for Membraneless Organelles and Cellular Dynamics, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
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Ramamurthy T, Ghosh A, Chowdhury G, Mukhopadhyay AK, Dutta S, Miyoshi SI. Deciphering the genetic network and programmed regulation of antimicrobial resistance in bacterial pathogens. Front Cell Infect Microbiol 2022; 12:952491. [PMID: 36506027 PMCID: PMC9727169 DOI: 10.3389/fcimb.2022.952491] [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: 05/25/2022] [Accepted: 10/25/2022] [Indexed: 11/24/2022] Open
Abstract
Antimicrobial resistance (AMR) in bacteria is an important global health problem affecting humans, animals, and the environment. AMR is considered as one of the major components in the "global one health". Misuse/overuse of antibiotics in any one of the segments can impact the integrity of the others. In the presence of antibiotic selective pressure, bacteria tend to develop several defense mechanisms, which include structural changes of the bacterial outer membrane, enzymatic processes, gene upregulation, mutations, adaptive resistance, and biofilm formation. Several components of mobile genetic elements (MGEs) play an important role in the dissemination of AMR. Each one of these components has a specific function that lasts long, irrespective of any antibiotic pressure. Integrative and conjugative elements (ICEs), insertion sequence elements (ISs), and transposons carry the antimicrobial resistance genes (ARGs) on different genetic backbones. Successful transfer of ARGs depends on the class of plasmids, regulons, ISs proximity, and type of recombination systems. Additionally, phage-bacterial networks play a major role in the transmission of ARGs, especially in bacteria from the environment and foods of animal origin. Several other functional attributes of bacteria also get successfully modified to acquire ARGs. These include efflux pumps, toxin-antitoxin systems, regulatory small RNAs, guanosine pentaphosphate signaling, quorum sensing, two-component system, and clustered regularly interspaced short palindromic repeats (CRISPR) systems. The metabolic and virulence state of bacteria is also associated with a range of genetic and phenotypic resistance mechanisms. In spite of the availability of a considerable information on AMR, the network associations between selection pressures and several of the components mentioned above are poorly understood. Understanding how a pathogen resists and regulates the ARGs in response to antimicrobials can help in controlling the development of resistance. Here, we provide an overview of the importance of genetic network and regulation of AMR in bacterial pathogens.
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Affiliation(s)
- Thandavarayan Ramamurthy
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India,*Correspondence: Thandavarayan Ramamurthy,
| | - Amit Ghosh
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Goutam Chowdhury
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Asish K. Mukhopadhyay
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shanta Dutta
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shin-inchi Miyoshi
- Collaborative Research Centre of Okayama University for Infectious Diseases at ICMR- National Institute of Cholera and Enteric Diseases, Kolkata, India,Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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20
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Gosain TP, Singh M, Singh C, Thakur KG, Singh R. Disruption of MenT2 toxin impairs the growth of Mycobacterium tuberculosis in guinea pigs. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 36342835 DOI: 10.1099/mic.0.001246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Toxin-antitoxin (TA) systems are abundantly present in the genomes of various bacterial pathogens. TA systems have been implicated in either plasmid maintenance or protection against phage infection, stress adaptation or disease pathogenesis. The genome of Mycobacterium tuberculosis encodes for more than 90 TA systems and 4 of these belong to the type IV subfamily (MenAT family). The toxins and antitoxins belonging to type IV TA systems share sequence homology with the AbiEii family of nucleotidyl transferases and the AbiEi family of putative transcriptional regulators, respectively. Here, we have performed experiments to understand the role of MenT2, a toxin from the type IV TA system, in mycobacterial physiology and disease pathogenesis. The ectopic expression of MenT2 using inducible vectors does not inhibit bacterial growth in liquid cultures. Bioinformatic and molecular modelling analysis suggested that the M. tuberculosis genome has an alternative start site upstream of the annotated menT2 gene. The overexpression of the reannotated MenT2 resulted in moderate growth inhibition of Mycobacterium smegmatis. We show that both menT2 and menA2 transcript levels are increased when M. tuberculosis is exposed to nitrosative stress, in vitro. When compared to the survival of the wild-type and the complemented strain, the ΔmenT2 mutant strain of M. tuberculosis was more resistant to being killed by nitrosative stress. However, the survival of both the ΔmenT2 mutant and the wild-type strain was similar in macrophages and when exposed to other stress conditions. Here, we show that MenT2 is required for the establishment of disease in guinea pigs. Gross pathology and histopathology analysis of lung tissues from guinea pigs infected with the ∆menT2 strain revealed significantly reduced tissue damage and inflammation. In summary, these results provide new insights into the role of MenT2 in mycobacterial pathogenesis.
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Affiliation(s)
- Tannu Priya Gosain
- Infection and Immunology Group, Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR-Biotech Science Cluster, 3rd Milestone, Faridabad Gurugram Expressway, Faridabad-121001, India
| | - Manisha Singh
- Infection and Immunology Group, Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR-Biotech Science Cluster, 3rd Milestone, Faridabad Gurugram Expressway, Faridabad-121001, India
| | - Charandeep Singh
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh-160036, India
| | - Krishan Gopal Thakur
- Structural Biology Laboratory, G. N. Ramachandran Protein Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh-160036, India
| | - Ramandeep Singh
- Infection and Immunology Group, Tuberculosis Research Laboratory, Translational Health Science and Technology Institute, NCR-Biotech Science Cluster, 3rd Milestone, Faridabad Gurugram Expressway, Faridabad-121001, India
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21
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Dai Z, Wu T, Xu S, Zhou L, Tang W, Hu E, Zhan L, Chen M, Yu G. Characterization of toxin-antitoxin systems from public sequencing data: A case study in Pseudomonas aeruginosa. Front Microbiol 2022; 13:951774. [PMID: 36051757 PMCID: PMC9424990 DOI: 10.3389/fmicb.2022.951774] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/15/2022] [Indexed: 11/13/2022] Open
Abstract
The toxin-antitoxin (TA) system is a widely distributed group of genetic modules that play important roles in the life of prokaryotes, with mobile genetic elements (MGEs) contributing to the dissemination of antibiotic resistance gene (ARG). The diversity and richness of TA systems in Pseudomonas aeruginosa, as one of the bacterial species with ARGs, have not yet been completely demonstrated. In this study, we explored the TA systems from the public genomic sequencing data and genome sequences. A small scale of genomic sequencing data in 281 isolates was selected from the NCBI SRA database, reassembling the genomes of these isolates led to the findings of abundant TA homologs. Furthermore, remapping these identified TA modules on 5,437 genome/draft genomes uncovers a great diversity of TA modules in P. aeruginosa. Moreover, manual inspection revealed several TA systems that were not yet reported in P. aeruginosa including the hok-sok, cptA-cptB, cbeA-cbtA, tomB-hha, and ryeA-sdsR. Additional annotation revealed that a large number of MGEs were closely distributed with TA. Also, 16% of ARGs are located relatively close to TA. Our work confirmed a wealth of TA genes in the unexplored P. aeruginosa pan-genomes, expanded the knowledge on P. aeruginosa, and provided methodological tips on large-scale data mining for future studies. The co-occurrence of MGE, ARG, and TA may indicate a potential interaction in their dissemination.
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22
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Song X, Lin Z, Yuan W. Toxin-antitoxin systems in pathogenic Vibrio species: a mini review from a structure perspective. 3 Biotech 2022; 12:125. [PMID: 35542053 DOI: 10.1007/s13205-022-03178-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/31/2022] [Indexed: 11/01/2022] Open
Abstract
Toxin-antitoxin (TA) genetic modules have been found to widely exist in bacterial chromosomes and mobile genetic elements. They are composed of stable toxins and less stable antitoxins that can counteract the toxicity of toxins. The interactions between toxins and antitoxins could play critical roles in the virulence and persistence of pathogenic bacteria. There are at least eight types of TA systems which have been identified in a variety of bacteria. Vibrio, a genus of Gram-negative bacteria, is widespread in aquatic environments and can cause various human diseases, such as epidemic cholera. In this review, we mainly explore the structures and functions of TA modules found in common Vibrio pathogens, mainly V. cholerae, for better understanding of TA action mechanisms in pathogenic bacteria.
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23
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Regulation of Mannitol Metabolism in Enterococcus faecalis and Association with parEF0409 Toxin-Antitoxin Locus Function. J Bacteriol 2022; 204:e0004722. [PMID: 35404112 DOI: 10.1128/jb.00047-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The parEF0409 type I toxin-antitoxin locus is situated between genes for two paralogous mannitol family phosphoenolpyruvate phosphotransferase systems (PTSs). In order to address the possibility that parEF0409 function was associated with sugar metabolism, genetic and phenotypic analyses were performed on the flanking genes. It was found that the genes were transcribed as two operons: the downstream operon essential for mannitol transport and metabolism and the upstream operon performing a regulatory function. In addition to genes for the PTS components, the upstream operon harbors a gene similar to mtlR, the key regulator of mannitol metabolism in other Gram-positive bacteria. We confirmed that this gene is essential for the regulation of the downstream operon and identified putative phosphorylation sites required for carbon catabolite repression and mannitol-specific regulation. Genomic comparisons revealed that this dual-operon organization of mannitol utilization genes is uncommon in enterococci and that the association with a toxin-antitoxin system is unique to Enterococcus faecalis. Finally, we consider possible links between parEF0409 function and mannitol utilization. IMPORTANCE Enterococcus faecalis is both a common member of the human gut microbiota and an opportunistic pathogen. Its evolutionary success is partially due to its metabolic flexibility, in particular its ability to import and metabolize a wide variety of sugars. While a large number of phosphoenolpyruvate phosphotransferase sugar transport systems have been identified in the E. faecalis genome bioinformatically, the specificity and regulation of most of these systems remain undetermined. Here, we characterize a complex system of two operons flanking a type I toxin-antitoxin system required for the transport and metabolism of the common dietary sugar mannitol. We also determine the phylogenetic distribution of mannitol utilization genes in the enterococcal genus and discuss the significance of the association with toxin-antitoxin systems.
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The role of PemIK (PemK/PemI) type II TA system from Klebsiella pneumoniae clinical strains in lytic phage infection. Sci Rep 2022; 12:4488. [PMID: 35296704 PMCID: PMC8927121 DOI: 10.1038/s41598-022-08111-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 02/21/2022] [Indexed: 01/17/2023] Open
Abstract
Since their discovery, toxin-antitoxin (TA) systems have captivated the attention of many scientists. Recent studies have demonstrated that TA systems play a key role in phage inhibition. The aim of the present study was to investigate the role of the PemIK (PemK/PemI) type II TA system in phage inhibition by its intrinsic expression in clinical strains of Klebsiella pneumoniae carrying the lncL plasmid, which harbours the carbapenemase OXA-48 and the PemK/PemI TA system. Furthermore, induced expression of the system in an IPTG-inducible plasmid in a reference strain of K. pneumoniae ATCC10031 was also studied. The results showed that induced expression of the whole TA system did not inhibit phage infection, whereas overexpression of the pemK toxin prevented early infection. To investigate the molecular mechanism involved in the PemK toxin-mediated inhibition of phage infection, assays measuring metabolic activity and viability were performed, revealing that overexpression of the PemK toxin led to dormancy of the bacteria. Thus, we demonstrate that the PemK/PemI TA system plays a role in phage infection and that the action of the free toxin induces a dormant state in the cells, resulting in inhibition of phage infections.
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Choi E, Huh A, Oh C, Oh JI, Kang HY, Hwang J. Functional characterization of HigBA toxin-antitoxin system in an Arctic bacterium, Bosea sp. PAMC 26642. J Microbiol 2022; 60:192-206. [PMID: 35102526 DOI: 10.1007/s12275-022-1619-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/15/2021] [Accepted: 12/20/2021] [Indexed: 01/02/2023]
Abstract
Toxin-antitoxin (TA) systems are growth-controlling genetic elements consisting of an intracellular toxin protein and its cognate antitoxin. TA systems have been spread among microbial genomes through horizontal gene transfer and are now prevalent in most bacterial and archaeal genomes. Under normal growth conditions, antitoxins tightly counteract the activity of the toxins. Upon stresses, antitoxins are inactivated, releasing activated toxins, which induce growth arrest or cell death. In this study, among nine functional TA modules in Bosea sp. PAMC 26642 living in Arctic lichen, we investigated the functionality of BoHigBA2. BohigBA2 is located close to a genomic island and adjacent to flagellar gene clusters. The expression of BohigB2 induced the inhibition of E. coli growth at 37°C, which was more manifest at 18°C, and this growth defect was reversed when BohigA2 was co-expressed, suggesting that this BoHigBA2 module might be an active TA module in Bosea sp. PAMC 26642. Live/dead staining and viable count analyses revealed that the BoHigB2 toxin had a bactericidal effect, causing cell death. Furthermore, we demonstrated that BoHigB2 possessed mRNA-specific ribonuclease activity on various mRNAs and cleaved only mRNAs being translated, which might impede overall translation and consequently lead to cell death. Our study provides the insight to understand the cold adaptation of Bosea sp. PAMC 26642 living in the Arctic.
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Affiliation(s)
- Eunsil Choi
- Department of Microbiology, Pusan National University, Busan, 46241, Republic of Korea.,Microbiological Resource Research Institute, Pusan National University, Busan, 46241, Republic of Korea
| | - Ahhyun Huh
- Department of Microbiology, Pusan National University, Busan, 46241, Republic of Korea
| | - Changmin Oh
- Department of Microbiology, Pusan National University, Busan, 46241, Republic of Korea
| | - Jeong-Il Oh
- Department of Microbiology, Pusan National University, Busan, 46241, Republic of Korea.,Microbiological Resource Research Institute, Pusan National University, Busan, 46241, Republic of Korea
| | - Ho Young Kang
- Department of Microbiology, Pusan National University, Busan, 46241, Republic of Korea.,Microbiological Resource Research Institute, Pusan National University, Busan, 46241, Republic of Korea
| | - Jihwan Hwang
- Department of Microbiology, Pusan National University, Busan, 46241, Republic of Korea. .,Microbiological Resource Research Institute, Pusan National University, Busan, 46241, Republic of Korea.
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Singh G, Yadav M, Ghosh C, Rathore JS. Bacterial toxin-antitoxin modules: classification, functions, and association with persistence. CURRENT RESEARCH IN MICROBIAL SCIENCES 2021; 2:100047. [PMID: 34841338 PMCID: PMC8610362 DOI: 10.1016/j.crmicr.2021.100047] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/04/2021] [Accepted: 07/05/2021] [Indexed: 11/24/2022] Open
Abstract
Ubiquitously present bacterial Toxin-Antitoxin (TA) modules consist of stable toxin associated with labile antitoxin. Classification of TAs modules based on inhibition of toxin through antitoxin in 8 different classes. Variety of specific toxin targets and the abundance of TA modules in various deadly pathogens. Specific role of TAs modules in conservation of the resistant genes, emergence of persistence & biofilm formation. Proposed antibacterial strategies involving TA modules for elimination of multi-drug resistance.
Toxin-antitoxin (TA) modules are ubiquitous gene loci among bacteria and are comprised of a toxin part and its cognate antitoxin part. Under normal physiological conditions, antitoxin counteracts the toxicity of the toxin whereas, during stress conditions, TA modules play a crucial role in bacterial physiology through involvement in the post-segregational killing, abortive infection, biofilms, and persister cell formation. Most of the toxins are proteinaceous that affect translation or DNA replication, although some other intracellular molecular targets have also been described. While antitoxins may be a protein or RNA, that generally neutralizes its cognate toxin by direct interaction or with the help of other signaling elements and thus helps in the TA module regulation. In this review, we have discussed the current state of the multifaceted TA (type I–VIII) modules by highlighting their classification and specific targets. We have also discussed the presence of TA modules in the various pathogens and their role in antibiotic persistence development as well as biofilm formation, by influencing the different cellular processes. In the end, assembling knowledge about ubiquitous TA systems from pathogenic bacteria facilitated us to propose multiple novel antibacterial strategies involving artificial activation of TA modules.
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Affiliation(s)
- Garima Singh
- School of Biotechnology, Gautam Buddha University, Greater Noida, Yamuna Expressway, Uttar Pradesh, India
| | - Mohit Yadav
- School of Biotechnology, Gautam Buddha University, Greater Noida, Yamuna Expressway, Uttar Pradesh, India
| | - Chaitali Ghosh
- Department of Zoology Gargi College, University of Delhi, New Delhi, India
| | - Jitendra Singh Rathore
- School of Biotechnology, Gautam Buddha University, Greater Noida, Yamuna Expressway, Uttar Pradesh, India
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Yadav M, Rathore JS. Functional and transcriptional analysis of chromosomal encoded hipBA Xn2 type II toxin-antitoxin (TA) module from Xenorhabdus nematophila. Microb Pathog 2021; 162:105309. [PMID: 34839000 DOI: 10.1016/j.micpath.2021.105309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 10/26/2021] [Accepted: 11/22/2021] [Indexed: 02/06/2023]
Abstract
Xenorhabdus nematophila is an entomopathogenic bacterium that synthesizes numerous toxins and kills its larval insect host. Apart from such toxins, its genome also has a plethora of toxin-antitoxin (TA) systems. The role of TA systems in bacterial physiology is debatable; however, they are associated with maintaining bacterial genomic stability and their survival under adverse environmental conditions. Here, we explored the functionality and transcriptional regulation of the type II hipBAXn2 TA system. This TA system was identified in the genome of X. nematophila ATCC 19061, which consists of the hipAXn2 toxin gene encoding 278 amino acid residues and hipBXn2 encoding antitoxin of 135 amino acid residues. We showed that overexpression of HipAXn2 toxin reduced the growth of Escherichia coli cells in a bacteriostatic manner, and amino-acids G8, H164, N167, and S169 were key residues for this growth reduction. Promoter activity and expression profiling of the hipBAXn2 TA system was showed that transcription was induced in both E. coli as well as X. nematophila upon exposure to different stress conditions. Further, we have exhibited the binding features of HipAXn2 toxin and HipBXn2 antitoxin to their promoter. This study provides evidence for the presence of a functional and well-regulated hipBAXn2 TA system in X. nematophila.
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Affiliation(s)
- Mohit Yadav
- School of Biotechnology, Gautam Buddha University, Yamuna Expressway, Greater Noida, Uttar Pradesh, India
| | - Jitendra Singh Rathore
- School of Biotechnology, Gautam Buddha University, Yamuna Expressway, Greater Noida, Uttar Pradesh, India.
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Hill V, Akarsu H, Barbarroja RS, Cippà VL, Kuhnert P, Heller M, Falquet L, Heller M, Stoffel MH, Labroussaa F, Jores J. Minimalistic mycoplasmas harbor different functional toxin-antitoxin systems. PLoS Genet 2021; 17:e1009365. [PMID: 34673769 PMCID: PMC8562856 DOI: 10.1371/journal.pgen.1009365] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 11/02/2021] [Accepted: 09/29/2021] [Indexed: 11/19/2022] Open
Abstract
Mycoplasmas are minute bacteria controlled by very small genomes ranging from 0.6 to 1.4 Mbp. They encompass several important medical and veterinary pathogens that are often associated with a wide range of chronic diseases. The long persistence of mycoplasma cells in their hosts can exacerbate the spread of antimicrobial resistance observed for many species. However, the nature of the virulence factors driving this phenomenon in mycoplasmas is still unclear. Toxin-antitoxin systems (TA systems) are genetic elements widespread in many bacteria that were historically associated with bacterial persistence. Their presence on mycoplasma genomes has never been carefully assessed, especially for pathogenic species. Here we investigated three candidate TA systems in M. mycoides subsp. capri encoding a (i) novel AAA-ATPase/subtilisin-like serine protease module, (ii) a putative AbiEii/AbiEi pair and (iii) a putative Fic/RelB pair. We sequence analyzed fourteen genomes of M. mycoides subsp. capri and confirmed the presence of at least one TA module in each of them. Interestingly, horizontal gene transfer signatures were also found in several genomic loci containing TA systems for several mycoplasma species. Transcriptomic and proteomic data confirmed differential expression profiles of these TA systems during mycoplasma growth in vitro. While the use of heterologous expression systems based on E. coli and B. subtilis showed clear limitations, the functionality and neutralization capacities of all three candidate TA systems were successfully confirmed using M. capricolum subsp. capricolum as a host. Additionally, M. capricolum subsp. capricolum was used to confirm the presence of functional TA system homologs in mycoplasmas of the Hominis and Pneumoniae phylogenetic groups. Finally, we showed that several of these M. mycoides subsp. capri toxins tested in this study, and particularly the subtilisin-like serine protease, could be used to establish a kill switch in mycoplasmas for industrial applications.
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Affiliation(s)
- Virginia Hill
- Institute of Veterinary Bacteriology, University of Bern, Bern, Switzerland
- Graduate School for Biomedical Science, University of Bern, Bern, Switzerland
| | - Hatice Akarsu
- Institute of Veterinary Bacteriology, University of Bern, Bern, Switzerland
| | | | - Valentina L. Cippà
- Institute of Veterinary Bacteriology, University of Bern, Bern, Switzerland
| | - Peter Kuhnert
- Institute of Veterinary Bacteriology, University of Bern, Bern, Switzerland
| | - Martin Heller
- Friedrich-Loeffler-Institute—Federal Research Institute for Animal Health, Jena, Germany
| | - Laurent Falquet
- Biochemistry Unit, University of Fribourg and Swiss Institute of Bioinformatics, Fribourg, Switzerland
| | - Manfred Heller
- Proteomics and Mass Spectrometry Core Facility, Department for BioMedical Research (DBMR), University of Bern, Bern, Switzerland
| | - Michael H. Stoffel
- Division of Veterinary Anatomy, Department of Clinical Research and Veterinary Public Health, University of Bern, Bern, Switzerland
| | - Fabien Labroussaa
- Institute of Veterinary Bacteriology, University of Bern, Bern, Switzerland
| | - Joerg Jores
- Institute of Veterinary Bacteriology, University of Bern, Bern, Switzerland
- * E-mail:
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Maggi S, Ferrari A, Yabre K, Bonini AA, Rivetti C, Folli C. Strategies to Investigate Membrane Damage, Nucleoid Condensation, and RNase Activity of Bacterial Toxin-Antitoxin Systems. Methods Protoc 2021; 4:mps4040071. [PMID: 34698227 PMCID: PMC8544347 DOI: 10.3390/mps4040071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/26/2021] [Accepted: 10/02/2021] [Indexed: 11/23/2022] Open
Abstract
A large number of bacterial toxin–antitoxin (TA) systems have been identified so far and different experimental approaches have been explored to investigate their activity and regulation both in vivo and in vitro. Nonetheless, a common feature of these methods is represented by the difficulty in cell transformation, culturing, and stability of the transformants, due to the expression of highly toxic proteins. Recently, in dealing with the type I Lpt/RNAII and the type II YafQ/DinJ TA systems, we encountered several of these problems that urged us to optimize methodological strategies to study the phenotype of recombinant Escherichia coli host cells. In particular, we have found conditions to tightly repress toxin expression by combining the pET expression system with the E. coli C41(DE3) pLysS strain. To monitor the RNase activity of the YafQ toxin, we developed a fluorescence approach based on Thioflavin-T which fluoresces brightly when complexed with bacterial RNA. Fluorescence microscopy was also applied to reveal loss of membrane integrity associated with the activity of the type I toxin Lpt, by using DAPI and ethidium bromide to selectively stain cells with impaired membrane permeability. We further found that atomic force microscopy can readily be employed to characterize toxin-induced membrane damages.
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Affiliation(s)
- Stefano Maggi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy; (S.M.); (A.A.B.)
| | - Alberto Ferrari
- Department of Food and Drug, University of Parma, 43124 Parma, Italy; (A.F.); (K.Y.)
| | - Korotoum Yabre
- Department of Food and Drug, University of Parma, 43124 Parma, Italy; (A.F.); (K.Y.)
| | - Aleksandra Anna Bonini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy; (S.M.); (A.A.B.)
| | - Claudio Rivetti
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy; (S.M.); (A.A.B.)
- Correspondence: (C.R.); (C.F.)
| | - Claudia Folli
- Department of Food and Drug, University of Parma, 43124 Parma, Italy; (A.F.); (K.Y.)
- Correspondence: (C.R.); (C.F.)
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Song Y, Zhang S, Luo G, Shen Y, Li C, Zhu Y, Huang Q, Mou X, Tang X, Liu T, Wu S, Tong A, He Y, Bao R. Type II Antitoxin HigA Is a Key Virulence Regulator in Pseudomonas aeruginosa. ACS Infect Dis 2021; 7:2930-2940. [PMID: 34554722 DOI: 10.1021/acsinfecdis.1c00401] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Bacterial type II toxin-antitoxin (TA) systems are abundant genetic elements and are involved in a diverse array of physiological processes. These systems encode an antitoxin protein that directly binds and effectively neutralizes the protein toxin. Recent studies have highlighted the key roles of type II TA modules in bacterial virulence and pathogenesis, but the underlying mechanisms remain unclear. Here, we investigated the antitoxin HigA in Pseudomonas aeruginosa infection. Proteomic analysis of the higA deletion strain revealed an enhanced expression of pathogenic proteins. We further verified that HigA negatively controlled T3SS and T6SS expression by directly interacting with the promoter regions of the regulators amrZ and exsA, respectively. In other words, the reversal of HigA-mediated transcriptional inhibition on stress stimulation could induce virulence genes. These findings confirm the crucial roles of the type II antitoxin in bacterial infection, which highlights the potential of the HigBA TA system as an antibacterial treatment target.
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Affiliation(s)
- Yingjie Song
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu 610093, China
| | - Siping Zhang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China
| | - Guihua Luo
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu 610093, China
| | - Yalin Shen
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu 610093, China
| | - Changcheng Li
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu 610093, China
| | - Yibo Zhu
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu 610093, China
| | - Qin Huang
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu 610093, China
| | - Xingyu Mou
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu 610093, China
| | - Xinyue Tang
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu 610093, China
| | - Tonggen Liu
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu 610093, China
| | - Siying Wu
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610044, China
| | - Aiping Tong
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu 610093, China
| | - Yongxing He
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China
| | - Rui Bao
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu 610093, China
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Garcia-Rodriguez G, Girardin Y, Volkov AN, Singh RK, Muruganandam G, Van Dyck J, Sobott F, Versées W, Charlier D, Loris R. Entropic pressure controls the oligomerization of the Vibrio cholerae ParD2 antitoxin. Acta Crystallogr D Struct Biol 2021; 77:904-920. [PMID: 34196617 PMCID: PMC8251345 DOI: 10.1107/s2059798321004873] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 05/07/2021] [Indexed: 11/22/2022] Open
Abstract
ParD2 is the antitoxin component of the parDE2 toxin-antitoxin module from Vibrio cholerae and consists of an ordered DNA-binding domain followed by an intrinsically disordered ParE-neutralizing domain. In the absence of the C-terminal intrinsically disordered protein (IDP) domain, V. cholerae ParD2 (VcParD2) crystallizes as a doughnut-shaped hexadecamer formed by the association of eight dimers. This assembly is stabilized via hydrogen bonds and salt bridges rather than by hydrophobic contacts. In solution, oligomerization of the full-length protein is restricted to a stable, open decamer or dodecamer, which is likely to be a consequence of entropic pressure from the IDP tails. The relative positioning of successive VcParD2 dimers mimics the arrangement of Streptococcus agalactiae CopG dimers on their operator and allows an extended operator to wrap around the VcParD2 oligomer.
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Affiliation(s)
- Gabriela Garcia-Rodriguez
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
- VIB–VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050 Brussels, Belgium
| | - Yana Girardin
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
- VIB–VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050 Brussels, Belgium
| | - Alexander N. Volkov
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
- VIB–VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050 Brussels, Belgium
- Jean Jeener NMR Center, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Ranjan Kumar Singh
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
- VIB–VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050 Brussels, Belgium
| | - Gopinath Muruganandam
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
- VIB–VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050 Brussels, Belgium
| | - Jeroen Van Dyck
- Department of Chemistry, Universiteit Antwerpen, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Frank Sobott
- Department of Chemistry, Universiteit Antwerpen, Groenenborgerlaan 171, 2020 Antwerp, Belgium
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Wim Versées
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
- VIB–VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050 Brussels, Belgium
| | - Daniel Charlier
- Research Group of Microbiology, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Remy Loris
- Structural Biology Brussels, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
- VIB–VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Pleinlaan 2, 1050 Brussels, Belgium
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Kamruzzaman M, Wu AY, Iredell JR. Biological Functions of Type II Toxin-Antitoxin Systems in Bacteria. Microorganisms 2021; 9:microorganisms9061276. [PMID: 34208120 PMCID: PMC8230891 DOI: 10.3390/microorganisms9061276] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/04/2021] [Accepted: 06/07/2021] [Indexed: 12/14/2022] Open
Abstract
After the first discovery in the 1980s in F-plasmids as a plasmid maintenance system, a myriad of toxin-antitoxin (TA) systems has been identified in bacterial chromosomes and mobile genetic elements (MGEs), including plasmids and bacteriophages. TA systems are small genetic modules that encode a toxin and its antidote and can be divided into seven types based on the nature of the antitoxin molecules and their mechanism of action to neutralise toxins. Among them, type II TA systems are widely distributed in chromosomes and plasmids and the best studied so far. Maintaining genetic material may be the major function of type II TA systems associated with MGEs, but the chromosomal TA systems contribute largely to functions associated with bacterial physiology, including the management of different stresses, virulence and pathogenesis. Due to growing interest in TA research, extensive work has been conducted in recent decades to better understand the physiological roles of these chromosomally encoded modules. However, there are still controversies about some of the functions associated with different TA systems. This review will discuss the most current findings and the bona fide functions of bacterial type II TA systems.
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Affiliation(s)
- Muhammad Kamruzzaman
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia;
- Correspondence: (M.K.); (J.R.I.)
| | - Alma Y. Wu
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia;
| | - Jonathan R. Iredell
- Centre for Infectious Diseases and Microbiology, The Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW 2145, Australia;
- Westmead Hospital, Westmead, NSW 2145, Australia
- Correspondence: (M.K.); (J.R.I.)
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Identification of Three Type II Toxin-Antitoxin Systems in Model Bacterial Plant Pathogen Dickeya dadantii 3937. Int J Mol Sci 2021; 22:ijms22115932. [PMID: 34073004 PMCID: PMC8198452 DOI: 10.3390/ijms22115932] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 05/28/2021] [Accepted: 05/28/2021] [Indexed: 11/17/2022] Open
Abstract
Type II toxin-antitoxin (TA) systems are genetic elements usually encoding two proteins: a stable toxin and an antitoxin, which binds the toxin and neutralizes its toxic effect. The disturbance in the intracellular toxin and antitoxin ratio typically leads to inhibition of bacterial growth or bacterial cell death. Despite the fact that TA modules are widespread in bacteria and archaea, the biological role of these systems is ambiguous. Nevertheless, a number of studies suggests that the TA modules are engaged in such important processes as biofilm formation, stress response or virulence and maintenance of mobile genetic elements. The Dickeya dadantii 3937 strain serves as a model for pathogens causing the soft-rot disease in a wide range of angiosperm plants. Until now, several chromosome-encoded type II TA systems were identified in silico in the genome of this economically important bacterium, however so far only one of them was experimentally validated. In this study, we investigated three putative type II TA systems in D. dadantii 3937: ccdAB2Dda, phd-docDda and dhiTA, which represents a novel toxin/antitoxin superfamily. We provide an experimental proof for their functionality in vivo both in D. dadantii and Escherichia coli. Finally, we examined the prevalence of those systems across the Pectobacteriaceae family by a phylogenetic analysis.
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Xia K, Ma J, Liang X. Impacts of type II toxin-antitoxin systems on cell physiology and environmental behavior in acetic acid bacteria. Appl Microbiol Biotechnol 2021; 105:4357-4367. [PMID: 34021811 DOI: 10.1007/s00253-021-11357-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 05/08/2021] [Accepted: 05/16/2021] [Indexed: 12/19/2022]
Abstract
Acetic acid bacteria (AAB) are a group of Gram-negative and strictly aerobic microorganisms widely used in vinegar industry, especially the species belonging to the genera Acetobacter and Komagataeibacter. The environments inhabited by AAB during the vinegar fermentation, in particular those natural traditional bioprocesses, are complex and dynamically changed, usually accompanied by diverse microorganisms, bacteriophages, and the increasing acetic acid concentration. For this reason, how AAB survive to such harsh niches has always been an interesting research field. Previous omic analyses (e.g., genomics, proteomics, and transcriptomics) have provided abundant clues for the metabolic pathways and bioprocesses indispensable for the acid stress adaptation of AAB. Nevertheless, it is far from fully understanding what factors regulate these modular mechanisms overtly and covertly upon shifting environments. Bacterial toxin-antitoxin systems (TAS), usually consisting of a pair of genes encoding a stable toxin and an unstable antitoxin that is capable of counteracting the toxin, have been uncovered to have a variety of biological functions. Recent studies focusing on the role of TAS in Acetobacter pasteurianus suggest that TAS contribute substantially to the acid stress resistance. In this mini review, we discuss the biological functions of type II TAS in the context of AAB with regard to the acid stress resistance, persister formation and resuscitation, genome stability, and phage immunity. KEY POINTS: • Type II TAS act as regulators in the acid stress resistance of AAB. • Type II TAS are implicated in the formation of acid-tolerant persister cells in AAB. • Type II TAS are potential factors responsible for phage immunity and genome stability.
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Affiliation(s)
- Kai Xia
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Jiawen Ma
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China.,Institute of Food Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Xinle Liang
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China. .,Institute of Food Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China.
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Sarpong DD, Murphy ER. RNA Regulated Toxin-Antitoxin Systems in Pathogenic Bacteria. Front Cell Infect Microbiol 2021; 11:661026. [PMID: 34084755 PMCID: PMC8167048 DOI: 10.3389/fcimb.2021.661026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 04/29/2021] [Indexed: 01/05/2023] Open
Abstract
The dynamic host environment presents a significant hurdle that pathogenic bacteria must overcome to survive and cause diseases. Consequently, these organisms have evolved molecular mechanisms to facilitate adaptation to environmental changes within the infected host. Small RNAs (sRNAs) have been implicated as critical regulators of numerous pathways and systems in pathogenic bacteria, including that of bacterial Toxin-Antitoxin (TA) systems. TA systems are typically composed of two factors, a stable toxin, and a labile antitoxin which functions to protect against the potentially deleterious activity of the associated toxin. Of the six classes of bacterial TA systems characterized to date, the toxin component is always a protein. Type I and Type III TA systems are unique in that the antitoxin in these systems is an RNA molecule, whereas the antitoxin in all other TA systems is a protein. Though hotly debated, the involvement of TA systems in bacterial physiology is recognized by several studies, with the Type II TA system being the most extensively studied to date. This review focuses on RNA-regulated TA systems, highlighting the role of Type I and Type III TA systems in several pathogenic bacteria.
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Affiliation(s)
- David D. Sarpong
- Department of Biological Sciences, Ohio University, Athens, OH, United States
- Infectious and Tropical Diseases Institute, Ohio University, Athens, OH, United States
- Molecular and Cellular Biology Program, Ohio University, Athens, OH, United States
| | - Erin R. Murphy
- Infectious and Tropical Diseases Institute, Ohio University, Athens, OH, United States
- Molecular and Cellular Biology Program, Ohio University, Athens, OH, United States
- Department of Biomedical Sciences, Ohio University, Heritage College of Osteopathic Medicine, Athens, OH, United States
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Chlebicka K, Bonar E, Suder P, Ostyn E, Felden B, Wladyka B, Pinel-Marie ML. Impacts of the Type I Toxin-Antitoxin System, SprG1/SprF1, on Staphylococcus aureus Gene Expression. Genes (Basel) 2021; 12:genes12050770. [PMID: 34070083 PMCID: PMC8158120 DOI: 10.3390/genes12050770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/14/2021] [Accepted: 05/16/2021] [Indexed: 11/16/2022] Open
Abstract
Type I toxin-antitoxin (TA) systems are widespread genetic modules in bacterial genomes. They express toxic peptides whose overexpression leads to growth arrest or cell death, whereas antitoxins regulate the expression of toxins, acting as labile antisense RNAs. The Staphylococcus aureus (S. aureus) genome contains and expresses several functional type I TA systems, but their biological functions remain unclear. Here, we addressed and challenged experimentally, by proteomics, if the type I TA system, the SprG1/SprF1 pair, influences the overall gene expression in S. aureus. Deleted and complemented S. aureus strains were analyzed for their proteomes, both intracellular and extracellular, during growth. Comparison of intracellular proteomes among the strains points to the SprF1 antitoxin as moderately downregulating protein expression. In the strain naturally expressing the SprG1 toxin, cytoplasmic proteins are excreted into the medium, but this is not due to unspecific cell leakages. Such a toxin-driven release of the cytoplasmic proteins may modulate the host inflammatory response that, in turn, could amplify the S. aureus infection spread.
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Affiliation(s)
- Kinga Chlebicka
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (K.C.); (E.B.)
| | - Emilia Bonar
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (K.C.); (E.B.)
| | - Piotr Suder
- Department of Analytical Chemistry and Biochemistry, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, 31-007 Krakow, Poland;
| | - Emeline Ostyn
- Inserm, BRM [Bacterial Regulatory RNAs and Medicine]—UMR_S 1230, 35000 Rennes, France;
| | - Brice Felden
- Inserm, BRM [Bacterial Regulatory RNAs and Medicine]—UMR_S 1230, 35000 Rennes, France;
| | - Benedykt Wladyka
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland; (K.C.); (E.B.)
- Correspondence: (B.W.); (M.-L.P.-M.); Tel.: +48-126646511 (B.W.); +33-223234850 (M.-L.P.-M.)
| | - Marie-Laure Pinel-Marie
- Inserm, BRM [Bacterial Regulatory RNAs and Medicine]—UMR_S 1230, 35000 Rennes, France;
- Correspondence: (B.W.); (M.-L.P.-M.); Tel.: +48-126646511 (B.W.); +33-223234850 (M.-L.P.-M.)
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Charged Residues Flanking the Transmembrane Domain of Two Related Toxin-Antitoxin System Toxins Affect Host Response. Toxins (Basel) 2021; 13:toxins13050329. [PMID: 34062876 PMCID: PMC8147318 DOI: 10.3390/toxins13050329] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/29/2021] [Accepted: 04/30/2021] [Indexed: 11/30/2022] Open
Abstract
A majority of toxins produced by type I toxin–antitoxin (TA-1) systems are small membrane-localized proteins that were initially proposed to kill cells by forming non-specific pores in the cytoplasmic membrane. The examination of the effects of numerous TA-1 systems indicates that this is not the mechanism of action of many of these proteins. Enterococcus faecalis produces two toxins of the Fst/Ldr family, one encoded on pheromone-responsive conjugative plasmids (FstpAD1) and the other on the chromosome, FstEF0409. Previous results demonstrated that overexpression of the toxins produced a differential transcriptomic response in E. faecalis cells. In this report, we identify the specific amino acid differences between the two toxins responsible for the differential response of a gene highly induced by FstpAD1 but not FstEF0409. In addition, we demonstrate that a transporter protein that is genetically linked to the chromosomal version of the TA-1 system functions to limit the toxicity of the protein.
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He Z, Li T, Wang J, Luo D, Ning N, Li Z, Chen F, Wang H. AtaT Improves the Stability of Pore-Forming Protein EspB by Acetylating Lysine 206 to Enhance Strain Virulence. Front Microbiol 2021; 12:627141. [PMID: 33732222 PMCID: PMC7957018 DOI: 10.3389/fmicb.2021.627141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 01/27/2021] [Indexed: 12/13/2022] Open
Abstract
A novel type II toxin of toxin–antitoxin systems (TAs), Gcn5-related N-acetyltransferase (GNAT) family, was reported recently. GNAT toxins are mainly present in pathogenic species, but studies of their involvement in pathogenicity are rare. This study discovered that the GANT toxin AtaT in enterohemorrhagic Escherichia coli (EHEC) can significantly enhance strain pathogenicity. First, we detected the virulence of ΔataT and ΔataR in cell and animal models. In the absence of ataT, strains showed a lower adhesion number, and host cells presented weaker attaching and effacing lesions, inflammatory response, and pathological injury. Next, we screened the acetylation substrate of AtaT to understand the underlying mechanism. Results showed that E. coli pore-forming protein EspB, which acts as a translocon in type III secretion system (T3SS) in strains, can be acetylated specifically by AtaT. The acetylation of K206 in EspB increases protein stability and maintains the efficiency of effectors translocating into host cells to cause close adhesion and tissue damage.
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Affiliation(s)
- Zhili He
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Tao Li
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Jianxin Wang
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Deyan Luo
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Nianzhi Ning
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Zhan Li
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Fanghong Chen
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
| | - Hui Wang
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China
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Srivastava A, Pati S, Kaushik H, Singh S, Garg LC. Toxin-antitoxin systems and their medical applications: current status and future perspective. Appl Microbiol Biotechnol 2021; 105:1803-1821. [PMID: 33582835 DOI: 10.1007/s00253-021-11134-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 01/13/2021] [Accepted: 01/20/2021] [Indexed: 12/11/2022]
Abstract
Almost all bacteria synthesize two types of toxins-one for its survival by regulating different cellular processes and another as a strategy to interact with host cells for pathogenesis. Usually, "bacterial toxins" are contemplated as virulence factors that harm the host organism. However, toxins produced by bacteria, as a survival strategy against the host, also hamper its cellular processes. To overcome this, the bacteria have evolved with the production of a molecule, referred to as antitoxin, to negate the deleterious effect of the toxin against itself. The toxin and antitoxins are encoded by a two-component toxin-antitoxin (TA) system. The antitoxin, a protein or RNA, sequesters the toxins of the TA system for neutralization within the bacterial cell. In this review, we have described different TA systems of bacteria and their potential medical and biotechnological applications. It is of interest to note that while bacterial toxin-antitoxin systems have been well studied, the TA system in unicellular eukaryotes, though predicted by the investigators, have never been paid the desired attention. In the present review, we have also touched upon the TA system of eukaryotes identified to date. KEY POINTS: Bacterial toxins harm the host and also affect the bacterial cellular processes. The antitoxin produced by bacteria protect it from the toxin's harmful effects. The toxin-antitoxin systems can be targeted for various medical applications.
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Affiliation(s)
- Akriti Srivastava
- Department of Life Sciences, Shiv Nadar University, Gautam Buddha Nagar, Greater Noida, Uttar Pradesh, 201314, India
| | - Soumya Pati
- Department of Life Sciences, Shiv Nadar University, Gautam Buddha Nagar, Greater Noida, Uttar Pradesh, 201314, India
| | - Himani Kaushik
- Gene Regulation Laboratory, National Institute of Immunology, New Delhi, 110067, India
| | - Shailja Singh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India.
| | - Lalit C Garg
- Gene Regulation Laboratory, National Institute of Immunology, New Delhi, 110067, India.
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Song Y, Luo G, Zhu Y, Li T, Li C, He L, Zhao N, Zhao C, Yang J, Huang Q, Mu X, Tang X, Kang M, Wu S, He Y, Bao R. Pseudomonas aeruginosa antitoxin HigA functions as a diverse regulatory factor by recognizing specific pseudopalindromic DNA motifs. Environ Microbiol 2020; 23:1541-1558. [PMID: 33346387 DOI: 10.1111/1462-2920.15365] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 02/05/2023]
Abstract
Type II toxin-antitoxin (TA) systems modulate many essential cellular processes in prokaryotic organisms. Recent studies indicate certain type II antitoxins also transcriptionally regulate other genes, besides neutralizing toxin activity. Herein, we investigated the diverse transcriptional repression properties of type II TA antitoxin PaHigA from Pseudomonas aeruginosa. Biochemical and functional analyses showed that PaHigA recognized variable pseudopalindromic DNA sequences and repressed expression of multiple genes. Furthermore, we presented high resolution structures of apo-PaHigA, PaHigA-PhigBA and PaHigA-Ppa2440 complex, describing how the rearrangements of the HTH domain accounted for the different DNA-binding patterns among HigA homologues. Moreover, we demonstrated that the N-terminal loop motion of PaHigA was associated with its apo and DNA-bound states, reflecting a switch mechanism regulating HigA antitoxin function. Collectively, this work extends our understanding of how the PaHigB/HigA system regulates multiple metabolic pathways to balance the growth and stress response in P. aeruginosa and could guide further development of anti-TA oriented strategies for pathogen treatment.
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Affiliation(s)
- Yingjie Song
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, China
| | - Guihua Luo
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, China
| | - Yibo Zhu
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, China
| | - Tao Li
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, China
| | - Changcheng Li
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, China
| | - Lihui He
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, China
| | - Ninglin Zhao
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, China
| | - Chang Zhao
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, China
| | - Jing Yang
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, China
| | - Qin Huang
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, China
| | - Xingyu Mu
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, China
| | - Xinyue Tang
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, China
| | - Mei Kang
- Department of Laboratory medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Siying Wu
- Department of Laboratory medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Yongxing He
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Rui Bao
- Center of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, China
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Songailiene I, Juozapaitis J, Tamulaitiene G, Ruksenaite A, Šulčius S, Sasnauskas G, Venclovas Č, Siksnys V. HEPN-MNT Toxin-Antitoxin System: The HEPN Ribonuclease Is Neutralized by OligoAMPylation. Mol Cell 2020; 80:955-970.e7. [PMID: 33290744 DOI: 10.1016/j.molcel.2020.11.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/11/2020] [Accepted: 11/19/2020] [Indexed: 10/22/2022]
Abstract
Prokaryotic toxin-antitoxin (TA) systems are composed of a toxin capable of interfering with key cellular processes and its neutralizing antidote, the antitoxin. Here, we focus on the HEPN-MNT TA system encoded in the vicinity of a subtype I-D CRISPR-Cas system in the cyanobacterium Aphanizomenon flos-aquae. We show that HEPN acts as a toxic RNase, which cleaves off 4 nt from the 3' end in a subset of tRNAs, thereby interfering with translation. Surprisingly, we find that the MNT (minimal nucleotidyltransferase) antitoxin inhibits HEPN RNase through covalent di-AMPylation (diadenylylation) of a conserved tyrosine residue, Y109, in the active site loop. Furthermore, we present crystallographic snapshots of the di-AMPylation reaction at different stages that explain the mechanism of HEPN RNase inactivation. Finally, we propose that the HEPN-MNT system functions as a cellular ATP sensor that monitors ATP homeostasis and, at low ATP levels, releases active HEPN toxin.
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Affiliation(s)
- Inga Songailiene
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Sauletekio av. 7, 10257 Vilnius, Lithuania
| | - Jonas Juozapaitis
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Sauletekio av. 7, 10257 Vilnius, Lithuania
| | - Giedre Tamulaitiene
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Sauletekio av. 7, 10257 Vilnius, Lithuania
| | - Audrone Ruksenaite
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Sauletekio av. 7, 10257 Vilnius, Lithuania
| | - Sigitas Šulčius
- Laboratory of Algology and Microbial Ecology, Nature Research Centre, Akademijos str. 2, 08412 Vilnius, Lithuania
| | - Giedrius Sasnauskas
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Sauletekio av. 7, 10257 Vilnius, Lithuania
| | - Česlovas Venclovas
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Sauletekio av. 7, 10257 Vilnius, Lithuania
| | - Virginijus Siksnys
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Sauletekio av. 7, 10257 Vilnius, Lithuania.
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Peltier J, Hamiot A, Garneau JR, Boudry P, Maikova A, Hajnsdorf E, Fortier LC, Dupuy B, Soutourina O. Type I toxin-antitoxin systems contribute to the maintenance of mobile genetic elements in Clostridioides difficile. Commun Biol 2020; 3:718. [PMID: 33247281 PMCID: PMC7699646 DOI: 10.1038/s42003-020-01448-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 11/03/2020] [Indexed: 12/15/2022] Open
Abstract
Toxin-antitoxin (TA) systems are widespread on mobile genetic elements and in bacterial chromosomes. In type I TA, synthesis of the toxin protein is prevented by the transcription of an antitoxin RNA. The first type I TA were recently identified in the human enteropathogen Clostridioides difficile. Here we report the characterization of five additional type I TA within phiCD630-1 (CD0977.1-RCd11, CD0904.1-RCd13 and CD0956.3-RCd14) and phiCD630-2 (CD2889-RCd12 and CD2907.2-RCd15) prophages of C. difficile strain 630. Toxin genes encode 34 to 47 amino acid peptides and their ectopic expression in C. difficile induces growth arrest that is neutralized by antitoxin RNA co-expression. We show that type I TA located within the phiCD630-1 prophage contribute to its stability and heritability. We have made use of a type I TA toxin gene to generate an efficient mutagenesis tool for this bacterium that allowed investigation of the role of these widespread TA in prophage maintenance.
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Affiliation(s)
- Johann Peltier
- Laboratoire Pathogenèse des Bactéries Anaérobies, CNRS-2001, Institut Pasteur, Université de Paris, 75015, Paris, France
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Audrey Hamiot
- Laboratoire Pathogenèse des Bactéries Anaérobies, CNRS-2001, Institut Pasteur, Université de Paris, 75015, Paris, France
- UMR UMET, INRA, CNRS, Univ. Lille 1, 59650, Villeneuve d'Ascq, France
| | - Julian R Garneau
- Faculty of Medicine and Health Sciences, Department of Microbiology and Infectious Diseases, Université de Sherbrooke, 3201 rue Jean Mignault, Sherbrooke, QC, J1E 4K8, Canada
| | - Pierre Boudry
- Laboratoire Pathogenèse des Bactéries Anaérobies, CNRS-2001, Institut Pasteur, Université de Paris, 75015, Paris, France
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette Cedex, France
| | - Anna Maikova
- Laboratoire Pathogenèse des Bactéries Anaérobies, CNRS-2001, Institut Pasteur, Université de Paris, 75015, Paris, France
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, 143028, Russia
- Peter the Great St. Petersburg Polytechnic University, Saint Petersburg, 195251, Russia
| | - Eliane Hajnsdorf
- Institut de Biologie Physico-Chimique, UMR8261, CNRS, Université de Paris, 13 rue Pierre et Marie Curie, 75005, Paris, France
| | - Louis-Charles Fortier
- Faculty of Medicine and Health Sciences, Department of Microbiology and Infectious Diseases, Université de Sherbrooke, 3201 rue Jean Mignault, Sherbrooke, QC, J1E 4K8, Canada
| | - Bruno Dupuy
- Laboratoire Pathogenèse des Bactéries Anaérobies, CNRS-2001, Institut Pasteur, Université de Paris, 75015, Paris, France
| | - Olga Soutourina
- Laboratoire Pathogenèse des Bactéries Anaérobies, CNRS-2001, Institut Pasteur, Université de Paris, 75015, Paris, France.
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France.
- Institut Universitaire de France (IUF), Paris, France.
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43
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Zhang W, Wu Q. Applications of phage-derived RNA-based technologies in synthetic biology. Synth Syst Biotechnol 2020; 5:343-360. [PMID: 33083579 PMCID: PMC7564126 DOI: 10.1016/j.synbio.2020.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 09/22/2020] [Accepted: 09/27/2020] [Indexed: 12/20/2022] Open
Abstract
As the most abundant biological entities with incredible diversity, bacteriophages (also known as phages) have been recognized as an important source of molecular machines for the development of genetic-engineering tools. At the same time, phages are crucial for establishing and improving basic theories of molecular biology. Studies on phages provide rich sources of essential elements for synthetic circuit design as well as powerful support for the improvement of directed evolution platforms. Therefore, phages play a vital role in the development of new technologies and central scientific concepts. After the RNA world hypothesis was proposed and developed, novel biological functions of RNA continue to be discovered. RNA and its related elements are widely used in many fields such as metabolic engineering and medical diagnosis, and their versatility led to a major role of RNA in synthetic biology. Further development of RNA-based technologies will advance synthetic biological tools as well as provide verification of the RNA world hypothesis. Most synthetic biology efforts are based on reconstructing existing biological systems, understanding fundamental biological processes, and developing new technologies. RNA-based technologies derived from phages will offer abundant sources for synthetic biological components. Moreover, phages as well as RNA have high impact on biological evolution, which is pivotal for understanding the origin of life, building artificial life-forms, and precisely reprogramming biological systems. This review discusses phage-derived RNA-based technologies terms of phage components, the phage lifecycle, and interactions between phages and bacteria. The significance of RNA-based technology derived from phages for synthetic biology and for understanding the earliest stages of biological evolution will be highlighted.
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Affiliation(s)
- Wenhui Zhang
- MOE Key Lab. Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Qiong Wu
- MOE Key Lab. Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Center for Synthetic and Systems Biology, Tsinghua University, Beijing, 100084, China
- Corresponding author. MOE Key Lab. Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
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44
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Ovchinnikov SV, Bikmetov D, Livenskyi A, Serebryakova M, Wilcox B, Mangano K, Shiriaev DI, Osterman IA, Sergiev PV, Borukhov S, Vazquez-Laslop N, Mankin AS, Severinov K, Dubiley S. Mechanism of translation inhibition by type II GNAT toxin AtaT2. Nucleic Acids Res 2020; 48:8617-8625. [PMID: 32597957 PMCID: PMC7470980 DOI: 10.1093/nar/gkaa551] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 06/05/2020] [Accepted: 06/17/2020] [Indexed: 12/25/2022] Open
Abstract
Type II toxin–antitoxins systems are widespread in prokaryotic genomes. Typically, they comprise two proteins, a toxin, and an antitoxin, encoded by adjacent genes and forming a complex in which the enzymatic activity of the toxin is inhibited. Under stress conditions, the antitoxin is degraded liberating the active toxin. Though thousands of various toxin–antitoxins pairs have been predicted bioinformatically, only a handful has been thoroughly characterized. Here, we describe the AtaT2 toxin from a toxin–antitoxin system from Escherichia coli O157:H7. We show that AtaT2 is the first GNAT (Gcn5-related N-acetyltransferase) toxin that specifically targets charged glycyl tRNA. In vivo, the AtaT2 activity induces ribosome stalling at all four glycyl codons but does not evoke a stringent response. In vitro, AtaT2 acetylates the aminoacyl moiety of isoaccepting glycyl tRNAs, thus precluding their participation in translation. Our study broadens the known target specificity of GNAT toxins beyond the earlier described isoleucine and formyl methionine tRNAs, and suggest that various GNAT toxins may have evolved to specificaly target other if not all individual aminoacyl tRNAs.
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Affiliation(s)
- Stepan V Ovchinnikov
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo 143025, Russia
| | - Dmitry Bikmetov
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia.,Institute of Gene Biology, Russian Academy of Science, 119334 Moscow, Russia
| | - Alexei Livenskyi
- Institute of Gene Biology, Russian Academy of Science, 119334 Moscow, Russia.,Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow 119992, Russia
| | - Marina Serebryakova
- Institute of Gene Biology, Russian Academy of Science, 119334 Moscow, Russia.,Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia
| | - Brendan Wilcox
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo 143025, Russia
| | - Kyle Mangano
- Center for Biomolecular Sciences, University of Illinois, Chicago, IL 60607, USA.,Department of Pharmaceutical Sciences, University of Illinois, Chicago, IL 60607, USA
| | - Dmitrii I Shiriaev
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119992, Russia
| | - Ilya A Osterman
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo 143025, Russia.,Department of Chemistry, Lomonosov Moscow State University, Moscow 119992, Russia
| | - Petr V Sergiev
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo 143025, Russia.,Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia
| | - Sergei Borukhov
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ 08084-1489, USA
| | - Nora Vazquez-Laslop
- Center for Biomolecular Sciences, University of Illinois, Chicago, IL 60607, USA.,Department of Pharmaceutical Sciences, University of Illinois, Chicago, IL 60607, USA
| | - Alexander S Mankin
- Center for Biomolecular Sciences, University of Illinois, Chicago, IL 60607, USA.,Department of Pharmaceutical Sciences, University of Illinois, Chicago, IL 60607, USA
| | - Konstantin Severinov
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo 143025, Russia.,Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia.,Waksman Institute for Microbiology, Piscataway, NJ 08854-8020, USA
| | - Svetlana Dubiley
- Centre for Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo 143025, Russia.,Institute of Gene Biology, Russian Academy of Science, 119334 Moscow, Russia
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45
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(p)ppGpp and Its Role in Bacterial Persistence: New Challenges. Antimicrob Agents Chemother 2020; 64:AAC.01283-20. [PMID: 32718971 DOI: 10.1128/aac.01283-20] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Antibiotic failure not only is due to the development of resistance by pathogens but can also often be explained by persistence and tolerance. Persistence and tolerance can be included in the "persistent phenotype," with high relevance for clinics. Two of the most important molecular mechanisms involved in tolerance and persistence are toxin-antitoxin (TA) modules and signaling via guanosine pentaphosphate/tetraphosphate [(p)ppGpp], also known as "magic spot." (p)ppGpp is a very important stress alarmone which orchestrates the stringent response in bacteria; hence, (p)ppGpp is produced during amino acid or fatty acid starvation by proteins belonging to the RelA/SpoT homolog family (RSH). However, (p)ppGpp levels can also accumulate in response to a wide range of signals, including oxygen variation, pH downshift, osmotic shock, temperature shift, or even exposure to darkness. Furthermore, the stringent response is not only involved in responses to environmental stresses (starvation for carbon sources, fatty acids, and phosphates or heat shock), but it is also used in bacterial pathogenesis, host invasion, and antibiotic tolerance and persistence. Given the exhaustive and contradictory literature surrounding the role of (p)ppGpp in bacterial persistence, and with the aim of summarizing what is known so far about the magic spot in this bacterial stage, this review provides new insights into the link between the stringent response and persistence. Moreover, we review some of the innovative treatments that have (p)ppGpp as a target, which are in the spotlight of the scientific community as candidates for effective antipersistence agents.
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46
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Song S, Wood TK. A Primary Physiological Role of Toxin/Antitoxin Systems Is Phage Inhibition. Front Microbiol 2020; 11:1895. [PMID: 32903830 PMCID: PMC7438911 DOI: 10.3389/fmicb.2020.01895] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 07/20/2020] [Indexed: 12/20/2022] Open
Abstract
Toxin/antitoxin (TA) systems are present in most prokaryote genomes. Toxins are almost exclusively proteins that reduce metabolism (but do not cause cell death), and antitoxins are either RNA or proteins that counteract the toxin or the RNA that encodes it. Although TA systems clearly stabilize mobile genetic elements, after four decades of research, the physiological roles of chromosomal TA systems are less clear. For example, recent reports have challenged the notion of TA systems as stress-response elements, including a role in creating the dormant state known as persistence. Here, we present evidence that a primary physiological role of chromosomally encoded TA systems is phage inhibition, a role that is also played by some plasmid-based TA systems. This includes results that show some CRISPR-Cas system elements are derived from TA systems and that some CRISPR-Cas systems mimic the host growth inhibition invoked by TA systems to inhibit phage propagation.
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Affiliation(s)
- Sooyeon Song
- Department of Animal Science, Jeonbuk National University, Jeonju-si, South Korea
| | - Thomas K Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, United States
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47
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Álvarez R, Ortega-Fuentes C, Queraltó C, Inostroza O, Díaz-Yáñez F, González R, Calderón IL, Fuentes JA, Paredes-Sabja D, Gil F. Evaluation of functionality of type II toxin-antitoxin systems of Clostridioides difficile R20291. Microbiol Res 2020; 239:126539. [PMID: 32622285 DOI: 10.1016/j.micres.2020.126539] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 06/20/2020] [Accepted: 06/24/2020] [Indexed: 01/05/2023]
Abstract
Clostridioides difficile is a nosocomial, Gram-positive, strictly anaerobic, spore-forming pathogen capable of colonizing and proliferating in the human intestine. In bacteria, it has been shown that the Toxin-Antitoxin systems mediate the cellular response to external stress by initiating processes such as biofilm formation and programmed cell death. This work aims to evaluate the functionality of four type II TA modules of Clostridioides difficile R20291. We performed bioinformatic analysis to search for putative TA systems using the TADB platform. Then we performed a heterologous expression assay to evaluate the functionality of these systems. Our results showed that the MazEF and RelBE systems were functional, suggesting that their corresponding toxins possess an endoribonuclease activity. In conclusion, MazEF and RelBE systems of C. difficile R20291 are functional in a heterologous expression system.
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Affiliation(s)
- R Álvarez
- Microbiota-Host Interactions and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - C Ortega-Fuentes
- Microbiota-Host Interactions and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - C Queraltó
- Microbiota-Host Interactions and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - O Inostroza
- Microbiota-Host Interactions and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - F Díaz-Yáñez
- Microbiota-Host Interactions and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile; Millennium Nucleus in the Biology of Intestinal Microbiota, Santiago, Chile
| | - R González
- Microbiota-Host Interactions and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - I L Calderón
- Laboratorio de RNAs bacterianos, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | - J A Fuentes
- Laboratorio de Genética y Patogénesis Bacteriana, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | - D Paredes-Sabja
- Microbiota-Host Interactions and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile; Millennium Nucleus in the Biology of Intestinal Microbiota, Santiago, Chile
| | - F Gil
- Microbiota-Host Interactions and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile; Millennium Nucleus in the Biology of Intestinal Microbiota, Santiago, Chile.
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48
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Janczak M, Hyz K, Bukowski M, Lyzen R, Hydzik M, Wegrzyn G, Szalewska-Palasz A, Grudnik P, Dubin G, Wladyka B. Chromosomal localization of PemIK toxin-antitoxin system results in the loss of toxicity - Characterization of pemIK Sa1-Sp from Staphylococcus pseudintermedius. Microbiol Res 2020; 240:126529. [PMID: 32622987 DOI: 10.1016/j.micres.2020.126529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 06/11/2020] [Accepted: 06/12/2020] [Indexed: 11/20/2022]
Abstract
Toxin-antitoxin (TA) systems are ubiquitous in bacteria and on numerous occasions have been postulated to play a role in virulence of pathogens. Some Staphylococcus aureus strains carry a plasmid, which encodes the highly toxic PemIKSa TA system involved in maintenance of the plasmid but also implicated in modulation of gene expression. Here we showed that pemIKSa1-Sp TA system, homologous to the plasmid-encoded PemIKSa, is present in virtually each chromosome of S. pseudintermedius strain, however exhibits sequence heterogeneity. This results in two length variants of the PemKSa1-Sp toxin. The shorter (96 aa), C-terminally truncated toxin is enzymatically inactive, whereas the full length (112 aa) variant is an RNase, though nontoxic to the host cells. The lack of toxicity of the active PemKSa-Sp2 toxin is explained by increased substrate specificity. The pemISa1-Sp antitoxin gene seems pseudogenized, however, the whole pemIKSa1-Sp system is transcriptionally active. When production of N-terminally truncated antitoxins using alternative start codons is assumed, there are five possible length variants. Here we showed that even substantially truncated antitoxins are able to interact with PemKSa-Sp2 toxin and inhibit its RNase activity. Moreover, the antitoxins can rescue bacterial cells from toxic effects of overexpression of plasmid-encoded PemKSa toxin. Collectively, our data indicates that, contrary to the toxic plasmid-encoded PemIKSa TA system, location of pemIKSa1-Sp in the chromosome of S. pseudintermedius results in the loss of its toxicity. Interestingly, the retained RNase activity of PemKSa1-Sp2 toxin and functionality of the putative, N-terminally truncated antitoxins suggest the existence of evolutionary pressure for alleviation/mitigation of the toxin's toxicity and retention of the inhibitory activity of the antitoxin, respectively.
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Affiliation(s)
- Monika Janczak
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Karolina Hyz
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Michal Bukowski
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Robert Lyzen
- Intercollegiate Faculty of Biotechnology UG&MUG, University of Gdansk, Gdansk, Poland
| | - Marcin Hydzik
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Grzegorz Wegrzyn
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Gdansk, Poland
| | | | - Przemyslaw Grudnik
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Grzegorz Dubin
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Benedykt Wladyka
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
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Cai Y, Usher B, Gutierrez C, Tolcan A, Mansour M, Fineran PC, Condon C, Neyrolles O, Genevaux P, Blower TR. A nucleotidyltransferase toxin inhibits growth of Mycobacterium tuberculosis through inactivation of tRNA acceptor stems. SCIENCE ADVANCES 2020; 6:eabb6651. [PMID: 32923609 PMCID: PMC7450476 DOI: 10.1126/sciadv.abb6651] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 06/12/2020] [Indexed: 05/12/2023]
Abstract
Toxin-antitoxin systems are widespread stress-responsive elements, many of whose functions remain largely unknown. Here, we characterize the four DUF1814-family nucleotidyltransferase-like toxins (MenT1-4) encoded by the human pathogen Mycobacterium tuberculosis. Toxin MenT3 inhibited growth of M. tuberculosis when not antagonized by its cognate antitoxin, MenA3. We solved the structures of toxins MenT3 and MenT4 to 1.6 and 1.2 Å resolution, respectively, and identified the biochemical activity and target of MenT3. MenT3 blocked in vitro protein expression and prevented tRNA charging in vivo. MenT3 added pyrimidines (C or U) to the 3'-CCA acceptor stems of uncharged tRNAs and exhibited strong substrate specificity in vitro, preferentially targeting tRNASer from among the 45 M. tuberculosis tRNAs. Our study identifies a previously unknown mechanism that expands the range of enzymatic activities used by bacterial toxins, uncovering a new way to block protein synthesis and potentially treat tuberculosis and other infections.
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Affiliation(s)
- Yiming Cai
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31400 Toulouse, France
| | - Ben Usher
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
| | - Claude Gutierrez
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, 31400 Toulouse, France
| | - Anastasia Tolcan
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Moise Mansour
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31400 Toulouse, France
| | - Peter C. Fineran
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Genetics Otago, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Bio-protection Research Centre, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Ciarán Condon
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Olivier Neyrolles
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, 31400 Toulouse, France
| | - Pierre Genevaux
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31400 Toulouse, France
| | - Tim R. Blower
- Department of Biosciences, Durham University, South Road, Durham DH1 3LE, UK
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50
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Multi-Stress Induction of the Mycobacterium tuberculosis MbcTA Bactericidal Toxin-Antitoxin System. Toxins (Basel) 2020; 12:toxins12050329. [PMID: 32429486 PMCID: PMC7291234 DOI: 10.3390/toxins12050329] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 11/16/2022] Open
Abstract
MbcTA is a type II toxin/antitoxin (TA) system of Mycobacterium tuberculosis. The MbcT toxin triggers mycobacterial cell death in vitro and in vivo through the phosphorolysis of the essential metabolite NAD+ and its bactericidal activity is neutralized by physical interaction with its cognate antitoxin MbcA. Therefore, the MbcTA system appears as a promising target for the development of novel therapies against tuberculosis, through the identification of compounds able to antagonize or destabilize the MbcA antitoxin. Here, the expression of the mbcAT operon and its regulation were investigated. A dual fluorescent reporter system was developed, based on an integrative mycobacterial plasmid that encodes a constitutively expressed reporter, serving as an internal standard for monitoring mycobacterial gene expression, and an additional reporter, dependent on the promoter under investigation. This system was used both in M. tuberculosis and in the fast growing model species Mycobacterium smegmatis to: (i) assess the autoregulation of mbcAT; (ii) perform a genetic dissection of the mbcA promoter/operator region; and (iii) explore the regulation of mbcAT transcription from the mbcA promoter (PmbcA) in a variety of stress conditions, including in vivo in mice and in macrophages.
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