1
|
Agapov A, Panteleev V, Kropocheva E, Kanevskaya A, Esyunina D, Kulbachinskiy A. Prokaryotic Argonaute nuclease cooperates with co-encoded RNase to acquire guide RNAs and target invader DNA. Nucleic Acids Res 2024; 52:5895-5911. [PMID: 38716875 PMCID: PMC11162769 DOI: 10.1093/nar/gkae345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 04/08/2024] [Accepted: 04/18/2024] [Indexed: 06/11/2024] Open
Abstract
Argonautes are an evolutionary conserved family of programmable nucleases that identify target nucleic acids using small guide oligonucleotides. In contrast to eukaryotic Argonautes (eAgos) that act on RNA, most studied prokaryotic Argonautes (pAgos) recognize DNA targets. Similarly to eAgos, pAgos can protect prokaryotic cells from invaders, but the biogenesis of guide oligonucleotides that confer them specificity to their targets remains poorly understood. Here, we have identified a new group of RNA-guided pAgo nucleases and demonstrated that a representative pAgo from this group, AmAgo from the mesophilic bacterium Alteromonas macleodii, binds guide RNAs of varying lengths for specific DNA targeting. Unlike most pAgos and eAgos, AmAgo is strictly specific to hydroxylated RNA guides containing a 5'-adenosine. AmAgo and related pAgos are co-encoded with a conserved RNA endonuclease from the HEPN superfamily (Ago-associated protein, Agap-HEPN). In vitro, Agap cleaves RNA between guanine and adenine nucleotides producing hydroxylated 5'-A guide oligonucleotides bound by AmAgo. In vivo, Agap cooperates with AmAgo in acquiring guide RNAs and counteracting bacteriophage infection. The AmAgo-Agap pair represents the first example of a pAgo system that autonomously produces RNA guides for DNA targeting and antiviral defense, which holds promise for programmable DNA targeting in biotechnology.
Collapse
Affiliation(s)
- Aleksei Agapov
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Vladimir Panteleev
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia
| | | | - Anna Kanevskaya
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
- Moscow Institute of Physics and Technology, Dolgoprudny 141700, Russia
| | - Daria Esyunina
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | | |
Collapse
|
2
|
Liu J, Yashiro Y, Sakaguchi Y, Suzuki T, Tomita K. Substrate specificity of Mycobacterium tuberculosis tRNA terminal nucleotidyltransferase toxin MenT3. Nucleic Acids Res 2024; 52:5987-6001. [PMID: 38485701 PMCID: PMC11162799 DOI: 10.1093/nar/gkae177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 02/13/2024] [Accepted: 02/28/2024] [Indexed: 06/11/2024] Open
Abstract
Mycobacterium tuberculosis transfer RNA (tRNA) terminal nucleotidyltransferase toxin, MenT3, incorporates nucleotides at the 3'-CCA end of tRNAs, blocking their aminoacylation and inhibiting protein synthesis. Here, we show that MenT3 most effectively adds CMPs to the 3'-CCA end of tRNA. The crystal structure of MenT3 in complex with CTP reveals a CTP-specific nucleotide-binding pocket. The 4-NH2 and the N3 and O2 atoms of cytosine in CTP form hydrogen bonds with the main-chain carbonyl oxygen of P120 and the side chain of R238, respectively. MenT3 expression in Escherichia coli selectively reduces the levels of seryl-tRNASers, indicating specific inactivation of tRNASers by MenT3. Consistently, MenT3 incorporates CMPs into tRNASer most efficiently, among the tested E. coli tRNA species. The longer variable loop unique to class II tRNASers is crucial for efficient CMP incorporation into tRNASer by MenT3. Replacing the variable loop of E. coli tRNAAla with the longer variable loop of M. tuberculosis tRNASer enables MenT3 to incorporate CMPs into the chimeric tRNAAla. The N-terminal positively charged region of MenT3 is required for CMP incorporation into tRNASer. A docking model of tRNA onto MenT3 suggests that an interaction between the N-terminal region and the longer variable loop of tRNASer facilitates tRNA substrate selection.
Collapse
Affiliation(s)
- Jun Liu
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Yuka Yashiro
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| | - Yuriko Sakaguchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Kozo Tomita
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan
| |
Collapse
|
3
|
Yuan Y, DeMott MS, Byrne SR, Flores K, Poyet M, Groussin M, Microbiome Conservancy G, Berdy B, Comstock L, Alm EJ, Dedon PC. Phosphorothioate DNA modification by BREX Type 4 systems in the human gut microbiome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.03.597175. [PMID: 38895356 PMCID: PMC11185695 DOI: 10.1101/2024.06.03.597175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Among dozens of microbial DNA modifications regulating gene expression and host defense, phosphorothioation (PT) is the only known backbone modification, with sulfur inserted at a non-bridging oxygen by dnd and ssp gene families. Here we explored the distribution of PT genes in 13,663 human gut microbiome genomes, finding that 6.3% possessed dnd or ssp genes predominantly in Bacillota, Bacteroidota, and Pseudomonadota. This analysis uncovered several putative new PT synthesis systems, including Type 4 Bacteriophage Exclusion (BREX) brx genes, which were genetically validated in Bacteroides salyersiae. Mass spectrometric analysis of DNA from 226 gut microbiome isolates possessing dnd, ssp, and brx genes revealed 8 PT dinucleotide settings confirmed in 6 consensus sequences by PT-specific DNA sequencing. Genomic analysis showed PT enrichment in rRNA genes and depletion at gene boundaries. These results illustrate the power of the microbiome for discovering prokaryotic epigenetics and the widespread distribution of oxidation-sensitive PTs in gut microbes.
Collapse
Affiliation(s)
- Yifeng Yuan
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Michael S. DeMott
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Center for Environmental Health Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Shane R. Byrne
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Katia Flores
- Department of Microbiology, Duchossois Family Institute, University of Chicago, Chicago, IL, USA
| | - Mathilde Poyet
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Institute of Experimental Medicine, Kiel University, Germany
- Global Microbiome Conservancy (https://microbiomeconservancy.org/), Kiel University, Germany
| | - Mathieu Groussin
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Institute of Clinical and Molecular Biology, Kiel University, Germany
- Global Microbiome Conservancy (https://microbiomeconservancy.org/), Kiel University, Germany
| | - Global Microbiome Conservancy
- Global Microbiome Conservancy (https://microbiomeconservancy.org/), Kiel University, Germany
- Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA
| | - Brittany Berdy
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Laurie Comstock
- Department of Microbiology, Duchossois Family Institute, University of Chicago, Chicago, IL, USA
| | - Eric J. Alm
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA
- Singapore-MIT Alliance for Research and Technology, Singapore
| | - Peter C. Dedon
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Center for Environmental Health Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Singapore-MIT Alliance for Research and Technology, Singapore
| |
Collapse
|
4
|
Bell RT, Sahakyan H, Makarova KS, Wolf YI, Koonin EV. CoCoNuTs are a diverse subclass of Type IV restriction systems predicted to target RNA. eLife 2024; 13:RP94800. [PMID: 38739430 PMCID: PMC11090510 DOI: 10.7554/elife.94800] [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] [Indexed: 05/14/2024] Open
Abstract
A comprehensive census of McrBC systems, among the most common forms of prokaryotic Type IV restriction systems, followed by phylogenetic analysis, reveals their enormous abundance in diverse prokaryotes and a plethora of genomic associations. We focus on a previously uncharacterized branch, which we denote coiled-coil nuclease tandems (CoCoNuTs) for their salient features: the presence of extensive coiled-coil structures and tandem nucleases. The CoCoNuTs alone show extraordinary variety, with three distinct types and multiple subtypes. All CoCoNuTs contain domains predicted to interact with translation system components, such as OB-folds resembling the SmpB protein that binds bacterial transfer-messenger RNA (tmRNA), YTH-like domains that might recognize methylated tmRNA, tRNA, or rRNA, and RNA-binding Hsp70 chaperone homologs, along with RNases, such as HEPN domains, all suggesting that the CoCoNuTs target RNA. Many CoCoNuTs might additionally target DNA, via McrC nuclease homologs. Additional restriction systems, such as Type I RM, BREX, and Druantia Type III, are frequently encoded in the same predicted superoperons. In many of these superoperons, CoCoNuTs are likely regulated by cyclic nucleotides, possibly, RNA fragments with cyclic termini, that bind associated CARF (CRISPR-Associated Rossmann Fold) domains. We hypothesize that the CoCoNuTs, together with the ancillary restriction factors, employ an echeloned defense strategy analogous to that of Type III CRISPR-Cas systems, in which an immune response eliminating virus DNA and/or RNA is launched first, but then, if it fails, an abortive infection response leading to PCD/dormancy via host RNA cleavage takes over.
Collapse
Affiliation(s)
- Ryan T Bell
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of HealthBethesdaUnited States
| | - Harutyun Sahakyan
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of HealthBethesdaUnited States
| | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of HealthBethesdaUnited States
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of HealthBethesdaUnited States
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of HealthBethesdaUnited States
| |
Collapse
|
5
|
Gapińska M, Zajko W, Skowronek K, Figiel M, Krawczyk P, Egorov A, Dziembowski A, Johansson MO, Nowotny M. Structure-functional characterization of Lactococcus AbiA phage defense system. Nucleic Acids Res 2024; 52:4723-4738. [PMID: 38587192 PMCID: PMC11077055 DOI: 10.1093/nar/gkae230] [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: 05/28/2023] [Revised: 02/01/2024] [Accepted: 03/20/2024] [Indexed: 04/09/2024] Open
Abstract
Bacterial reverse transcriptases (RTs) are a large and diverse enzyme family. AbiA, AbiK and Abi-P2 are abortive infection system (Abi) RTs that mediate defense against bacteriophages. What sets Abi RTs apart from other RT enzymes is their ability to synthesize long DNA products of random sequences in a template- and primer-independent manner. Structures of AbiK and Abi-P2 representatives have recently been determined, but there are no structural data available for AbiA. Here, we report the crystal structure of Lactococcus AbiA polymerase in complex with a single-stranded polymerization product. AbiA comprises three domains: an RT-like domain, a helical domain that is typical for Abi polymerases, and a higher eukaryotes and prokaryotes nucleotide-binding (HEPN) domain that is common for many antiviral proteins. AbiA forms a dimer that distinguishes it from AbiK and Abi-P2, which form trimers/hexamers. We show the DNA polymerase activity of AbiA in an in vitro assay and demonstrate that it requires the presence of the HEPN domain which is enzymatically inactive. We validate our biochemical and structural results in vivo through bacteriophage infection assays. Finally, our in vivo results suggest that AbiA-mediated phage defense may not rely on AbiA-mediated cell death.
Collapse
Affiliation(s)
- Marta Gapińska
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Weronika Zajko
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Krzysztof Skowronek
- Biophysics Core Facility, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Małgorzata Figiel
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Paweł S Krawczyk
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Artyom A Egorov
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Andrzej Dziembowski
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Marcus J O Johansson
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Marcin Nowotny
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw, Poland
| |
Collapse
|
6
|
Rostøl JT, Quiles-Puchalt N, Iturbe-Sanz P, Lasa Í, Penadés JR. Bacteriophages avoid autoimmunity from cognate immune systems as an intrinsic part of their life cycles. Nat Microbiol 2024; 9:1312-1324. [PMID: 38565896 PMCID: PMC11087260 DOI: 10.1038/s41564-024-01661-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 03/04/2024] [Indexed: 04/04/2024]
Abstract
Dormant prophages protect lysogenic cells by expressing diverse immune systems, which must avoid targeting their cognate prophages upon activation. Here we report that multiple Staphylococcus aureus prophages encode Tha (tail-activated, HEPN (higher eukaryotes and prokaryotes nucleotide-binding) domain-containing anti-phage system), a defence system activated by structural tail proteins of incoming phages. We demonstrate the function of two Tha systems, Tha-1 and Tha-2, activated by distinct tail proteins. Interestingly, Tha systems can also block reproduction of the induced tha-positive prophages. To prevent autoimmunity after prophage induction, these systems are inhibited by the product of a small overlapping antisense gene previously believed to encode an excisionase. This genetic organization, conserved in S. aureus prophages, allows Tha systems to protect prophages and their bacterial hosts against phage predation and to be turned off during prophage induction, balancing immunity and autoimmunity. Our results show that the fine regulation of these processes is essential for the correct development of prophages' life cycle.
Collapse
Affiliation(s)
- Jakob T Rostøl
- Centre for Bacterial Resistance Biology, Imperial College London, London, UK.
| | - Nuria Quiles-Puchalt
- Centre for Bacterial Resistance Biology, Imperial College London, London, UK
- School of Health Sciences, Universidad CEU Cardenal Herrera, CEU Universities, Alfara del Patriarca, Spain
| | - Pablo Iturbe-Sanz
- Laboratory of Microbial Pathogenesis. Navarrabiomed, Hospital Universitario de Navarra (HUN), Universidad Pública de Navarra (UPNA), IdiSNA, Pamplona, Spain
| | - Íñigo Lasa
- Laboratory of Microbial Pathogenesis. Navarrabiomed, Hospital Universitario de Navarra (HUN), Universidad Pública de Navarra (UPNA), IdiSNA, Pamplona, Spain
| | - José R Penadés
- Centre for Bacterial Resistance Biology, Imperial College London, London, UK.
| |
Collapse
|
7
|
Bell RT, Sahakyan H, Makarova KS, Wolf YI, Koonin EV. CoCoNuTs: A diverse subclass of Type IV restriction systems predicted to target RNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.31.551357. [PMID: 37790407 PMCID: PMC10542128 DOI: 10.1101/2023.07.31.551357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
A comprehensive census of McrBC systems, among the most common forms of prokaryotic Type IV restriction systems, followed by phylogenetic analysis, reveals their enormous abundance in diverse prokaryotes and a plethora of genomic associations. We focus on a previously uncharacterized branch, which we denote CoCoNuTs (coiled-coil nuclease tandems) for their salient features: the presence of extensive coiled-coil structures and tandem nucleases. The CoCoNuTs alone show extraordinary variety, with 3 distinct types and multiple subtypes. All CoCoNuTs contain domains predicted to interact with translation system components, such as OB-folds resembling the SmpB protein that binds bacterial transfer-messenger RNA (tmRNA), YTH-like domains that might recognize methylated tmRNA, tRNA, or rRNA, and RNA-binding Hsp70 chaperone homologs, along with RNases, such as HEPN domains, all suggesting that the CoCoNuTs target RNA. Many CoCoNuTs might additionally target DNA, via McrC nuclease homologs. Additional restriction systems, such as Type I RM, BREX, and Druantia Type III, are frequently encoded in the same predicted superoperons. In many of these superoperons, CoCoNuTs are likely regulated by cyclic nucleotides, possibly, RNA fragments with cyclic termini, that bind associated CARF (CRISPR-Associated Rossmann Fold) domains. We hypothesize that the CoCoNuTs, together with the ancillary restriction factors, employ an echeloned defense strategy analogous to that of Type III CRISPR-Cas systems, in which an immune response eliminating virus DNA and/or RNA is launched first, but then, if it fails, an abortive infection response leading to PCD/dormancy via host RNA cleavage takes over.
Collapse
Affiliation(s)
- Ryan T. Bell
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Harutyun Sahakyan
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Kira S. Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Yuri I. Wolf
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| |
Collapse
|
8
|
Bonabal S, Darfeuille F. Preventing toxicity in toxin-antitoxin systems: An overview of regulatory mechanisms. Biochimie 2024; 217:95-105. [PMID: 37473832 DOI: 10.1016/j.biochi.2023.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/13/2023] [Accepted: 07/17/2023] [Indexed: 07/22/2023]
Abstract
Toxin-antitoxin systems (TAs) are generally two-component genetic modules present in almost every prokaryotic genome. The production of the free and active toxin is able to disrupt key cellular processes leading to the growth inhibition or death of its host organism in absence of its cognate antitoxin. The functions attributed to TAs rely on this lethal phenotype ranging from mobile genetic elements stabilization to phage defense. Their abundance in prokaryotic genomes as well as their lethal potential make them attractive targets for new antibacterial strategies. The hijacking of TAs requires a deep understanding of their regulation to be able to design such approach. In this review, we summarize the accumulated knowledge on how bacteria cope with these toxic genes in their genome. The characterized TAs can be grouped based on the way they prevent toxicity. Some systems rely on a tight control of the expression to prevent the production of the toxin while others control the activity of the toxin at the post-translational level.
Collapse
Affiliation(s)
- Simon Bonabal
- University of Bordeaux, INSERM U1212, CNRS UMR 5320, ARNA Laboratory, F-33000, Bordeaux, France
| | - Fabien Darfeuille
- University of Bordeaux, INSERM U1212, CNRS UMR 5320, ARNA Laboratory, F-33000, Bordeaux, France.
| |
Collapse
|
9
|
Wang X, Kan Y, Bai K, Xu X, Chen X, Yu C, Shi J, Jiang N, Li J, Luo L. A novel double-ribonuclease toxin-antitoxin system linked to the stress response and survival of Acidovorax citrulli. Microbiol Spectr 2023; 11:e0216923. [PMID: 37819152 PMCID: PMC10714953 DOI: 10.1128/spectrum.02169-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/30/2023] [Indexed: 10/13/2023] Open
Abstract
IMPORTANCE Bacterial fruit blotch (BFB), which is caused by the seed-borne bacterium Acidovorax citrulli, is a devastating disease affecting cucurbit crops throughout the world. Although seed fermentation and treatment with disinfectants can provide effective management of BFB, they cannot completely guarantee pathogen-free seedstock, which suggests that A. citrulli is a highly stress-resistant pathogen. Toxin-antitoxin (TA) systems are common among a diverse range of bacteria and have been reported to play a role in bacterial stress response. However, there is currently much debate about the relationship between TA systems and stress response in bacteria. The current study characterized a novel TA system (Aave_1720-Aave_1719) from A. citrulli that affects both biofilm formation and survival in response to sodium hypochlorite stress. The mechanism of neutralization differed from typical TA systems as two separate mechanisms were associated with the antitoxin, which exhibited characteristics of both type II and type V TA systems. The Aave_1720-Aave_1719 system described here also constitutes the first known report of a double-ribonuclease TA system in bacteria, which expands our understanding of the range of regulatory mechanisms utilized by bacterial TA systems, providing new insight into the survival of A. citrulli in response to stress.
Collapse
Affiliation(s)
- Xudong Wang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Yumin Kan
- Department of Biochemistry and Cell Biology, State University of New York, Stony Brook, New York, USA
| | - Kaihong Bai
- School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China
| | - Xiaoli Xu
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Xing Chen
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Chengxuan Yu
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Jia Shi
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Na Jiang
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Jianqiang Li
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| | - Laixin Luo
- Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China
- Key Laboratory of Surveillance and Management for Plant Quarantine Pests, Ministry of Agriculture and Rural Affairs, Beijing, China
- Beijing Key Laboratory of Seed Disease Testing and Control, Beijing, China
| |
Collapse
|
10
|
Kang SM. Focused Overview of Mycobacterium tuberculosis VapBC Toxin-Antitoxin Systems Regarding Their Structural and Functional Aspects: Including Insights on Biomimetic Peptides. Biomimetics (Basel) 2023; 8:412. [PMID: 37754163 PMCID: PMC10526153 DOI: 10.3390/biomimetics8050412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/28/2023] Open
Abstract
Tuberculosis, caused by Mycobacterium tuberculosis, is a lethal infectious disease of significant public health concern. The rise of multidrug-resistant and drug-tolerant strains has necessitated novel approaches to combat the disease. Toxin-antitoxin (TA) systems, key players in bacterial adaptive responses, are prevalent in prokaryotic genomes and have been linked to tuberculosis. The genome of M. tuberculosis strains harbors an unusually high number of TA systems, prompting questions about their biological roles. The VapBC family, a representative type II TA system, is characterized by the VapC toxin, featuring a PilT N-terminal domain with nuclease activity. Its counterpart, VapB, functions as an antitoxin, inhibiting VapC's activity. Additionally, we explore peptide mimics designed to replicate protein helical structures in this review. Investigating these synthetic peptides offers fresh insights into molecular interactions, potentially leading to therapeutic applications. These synthetic peptides show promise as versatile tools for modulating cellular processes and protein-protein interactions. We examine the rational design strategies employed to mimic helical motifs, their biophysical properties, and potential applications in drug development and bioengineering. This review aims to provide an in-depth understanding of TA systems by introducing known complex structures, with a focus on both structural aspects and functional and molecular details associated with each system.
Collapse
Affiliation(s)
- Sung-Min Kang
- College of Pharmacy, Duksung Women's University, Seoul 01369, Republic of Korea
| |
Collapse
|
11
|
Chen Z, Yao J, Zhang P, Wang P, Ni S, Liu T, Zhao Y, Tang K, Sun Y, Qian Q, Wang X. Minimized antibiotic-free plasmid vector for gene therapy utilizing a new toxin-antitoxin system. Metab Eng 2023; 79:86-96. [PMID: 37451534 DOI: 10.1016/j.ymben.2023.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 06/28/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Approaches to improve plasmid-mediated transgene expression are needed for gene therapy and genetic immunization applications. The backbone sequences needed for the production of plasmids in bacterial hosts and the use of antibiotic resistance genes as selection markers represent biological safety risks. Here, we report the development of an antibiotic-free expression plasmid vector with a minimized backbone utilizing a new toxin-antitoxin (TA) system. The Rs_0636/Rs_0637 TA pair was derived from the coral-associated bacterium Roseivirga sp. The toxin gene is integrated into the chromosome of Escherichia coli host cells, and a recombinant mammalian expression plasmid is constructed by replacing the antibiotic resistance gene with the antitoxin gene Rs_0637 (here named Tiniplasmid). The Tiniplasmid system affords high selection efficiency (∼80%) for target gene insertion into the plasmid and has high plasmid stability in E. coli (at least 9 days) in antibiotic-free conditions. Furthermore, with the aim of reducing the size of the backbone sequence, we found that the antitoxin gene can be reduced to 153 bp without a significant reduction in selection efficiency. To develop its applications in gene therapy and DNA vaccines, the biosafety and efficiency of the Tiniplasmid-based eukaryotic gene delivery and expression were further evaluated in CHO-K1 cells. The results showed that Rs_0636/Rs_0637 has no cell toxicity and that the Tiniplasmid vector has a higher gene expression efficiency than the commercial vectors pCpGfree and pSTD in the eukaryotic cells. Altogether, the results demonstrate the potential of the Rs_0636/Rs_0637-based antibiotic-free plasmid vector for the development and production of safe and efficacious DNA vaccines.
Collapse
Affiliation(s)
- Zhe Chen
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Innovation Academy of South China Sea Ecology and Environmental Engineering, South China Sea Institute of Oceanology, Chinese Academy of Sciences, No. 1119, Haibin Road, Nansha District, Guangzhou, 511458, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jianyun Yao
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Innovation Academy of South China Sea Ecology and Environmental Engineering, South China Sea Institute of Oceanology, Chinese Academy of Sciences, No. 1119, Haibin Road, Nansha District, Guangzhou, 511458, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), No. 1119, Haibin Road, Nansha District, Guangzhou, 511458, China.
| | - Pingjing Zhang
- Maxirna (Shanghai) Pharmaceutical Co., Ltd., China; Shanghai Cell Therapy Group Co., Ltd, China
| | - Pengxia Wang
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Innovation Academy of South China Sea Ecology and Environmental Engineering, South China Sea Institute of Oceanology, Chinese Academy of Sciences, No. 1119, Haibin Road, Nansha District, Guangzhou, 511458, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), No. 1119, Haibin Road, Nansha District, Guangzhou, 511458, China
| | - Songwei Ni
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Innovation Academy of South China Sea Ecology and Environmental Engineering, South China Sea Institute of Oceanology, Chinese Academy of Sciences, No. 1119, Haibin Road, Nansha District, Guangzhou, 511458, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tao Liu
- Maxirna (Shanghai) Pharmaceutical Co., Ltd., China; Shanghai Cell Therapy Group Co., Ltd, China
| | - Yi Zhao
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Innovation Academy of South China Sea Ecology and Environmental Engineering, South China Sea Institute of Oceanology, Chinese Academy of Sciences, No. 1119, Haibin Road, Nansha District, Guangzhou, 511458, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Kaihao Tang
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Innovation Academy of South China Sea Ecology and Environmental Engineering, South China Sea Institute of Oceanology, Chinese Academy of Sciences, No. 1119, Haibin Road, Nansha District, Guangzhou, 511458, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), No. 1119, Haibin Road, Nansha District, Guangzhou, 511458, China
| | - Yan Sun
- Shanghai University Mengchao Cancer Hospital, China
| | - Qijun Qian
- Maxirna (Shanghai) Pharmaceutical Co., Ltd., China; Shanghai Cell Therapy Group Co., Ltd, China; Shanghai University Mengchao Cancer Hospital, China
| | - Xiaoxue Wang
- Key Laboratory of Tropical Marine Bioresources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, Innovation Academy of South China Sea Ecology and Environmental Engineering, South China Sea Institute of Oceanology, Chinese Academy of Sciences, No. 1119, Haibin Road, Nansha District, Guangzhou, 511458, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), No. 1119, Haibin Road, Nansha District, Guangzhou, 511458, China.
| |
Collapse
|
12
|
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.
Collapse
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.
| |
Collapse
|
13
|
Lewis AM, Willard DJ, H. Manesh MJ, Sivabalasarma S, Albers SV, Kelly RM. Stay or Go: Sulfolobales Biofilm Dispersal Is Dependent on a Bifunctional VapB Antitoxin. mBio 2023; 14:e0005323. [PMID: 37036347 PMCID: PMC10127717 DOI: 10.1128/mbio.00053-23] [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: 01/09/2023] [Accepted: 03/14/2023] [Indexed: 04/11/2023] Open
Abstract
A type II VapB14 antitoxin regulates biofilm dispersal in the archaeal thermoacidophile Sulfolobus acidocaldarius through traditional toxin neutralization but also through noncanonical transcriptional regulation. Type II VapC toxins are ribonucleases that are neutralized by their proteinaceous cognate type II VapB antitoxin. VapB antitoxins have a flexible tail at their C terminus that covers the toxin's active site, neutralizing its activity. VapB antitoxins also have a DNA-binding domain at their N terminus that allows them to autorepress not only their own promoters but also distal targets. VapB14 antitoxin gene deletion in S. acidocaldarius stunted biofilm and planktonic growth and increased motility structures (archaella). Conversely, planktonic cells were devoid of archaella in the ΔvapC14 cognate toxin mutant. VapB14 is highly conserved at both the nucleotide and amino acid levels across the Sulfolobales, extremely unusual for type II antitoxins, which are typically acquired through horizontal gene transfer. Furthermore, homologs of VapB14 are found across the Crenarchaeota, in some Euryarchaeota, and even bacteria. S. acidocaldarius vapB14 and its homolog in the thermoacidophile Metallosphaera sedula (Msed_0871) were both upregulated in biofilm cells, supporting the role of the antitoxin in biofilm regulation. In several Sulfolobales species, including M. sedula, homologs of vapB14 and vapC14 are not colocalized. Strikingly, Sulfuracidifex tepidarius has an unpaired VapB14 homolog and lacks a cognate VapC14, illustrating the toxin-independent conservation of the VapB14 antitoxin. The findings here suggest that a stand-alone VapB-type antitoxin was the product of selective evolutionary pressure to influence biofilm formation in these archaea, a vital microbial community behavior. IMPORTANCE Biofilms allow microbes to resist a multitude of stresses and stay proximate to vital nutrients. The mechanisms of entering and leaving a biofilm are highly regulated to ensure microbial survival, but are not yet well described in archaea. Here, a VapBC type II toxin-antitoxin system in the thermoacidophilic archaeon Sulfolobus acidocaldarius was shown to control biofilm dispersal through a multifaceted regulation of the archaeal motility structure, the archaellum. The VapC14 toxin degrades an RNA that causes an increase in archaella and swimming. The VapB14 antitoxin decreases archaella and biofilm dispersal by binding the VapC14 toxin and neutralizing its activity, while also repressing the archaellum genes. VapB14-like antitoxins are highly conserved across the Sulfolobales and respond similarly to biofilm growth. In fact, VapB14-like antitoxins are also found in other archaea, and even in bacteria, indicating an evolutionary pressure to maintain this protein and its role in biofilm formation.
Collapse
Affiliation(s)
- April M. Lewis
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Daniel J. Willard
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Mohamad J. H. Manesh
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Shamphavi Sivabalasarma
- Institute for Biology, Molecular Biology of Archaea, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg, Germany
| | - Sonja-Verena Albers
- Institute for Biology, Molecular Biology of Archaea, University of Freiburg, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBBS, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Robert M. Kelly
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| |
Collapse
|
14
|
Choi W, Maharjan A, Im HG, Park JY, Park JT, Park JH. Identification and Characterization of HEPN-MNT Type II TA System from Methanothermobacter thermautotrophicus ΔH. J Microbiol 2023; 61:411-421. [PMID: 37071293 DOI: 10.1007/s12275-023-00041-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 03/02/2023] [Accepted: 03/06/2023] [Indexed: 04/19/2023]
Abstract
Toxin-antitoxin (TA) systems are widespread in bacteria and archaea plasmids and genomes to regulate DNA replication, gene transcription, or protein translation. Higher eukaryotic and prokaryotic nucleotide-binding (HEPN) and minimal nucleotidyltransferase (MNT) domains are prevalent in prokaryotic genomes and constitute TA pairs. However, three gene pairs (MTH304/305, 408/409, and 463/464) of Methanothermobacter thermautotropicus ΔH HEPN-MNT family have not been studied as TA systems. Among these candidates, our study characterizes the MTH463/MTH464 TA system. MTH463 expression inhibited Escherichia coli growth, whereas MTH464 did not and blocked MTH463 instead. Using site-directed MTH463 mutagenesis, we determined that amino acids R99G, H104A, and Y106A from the R[ɸX]4-6H motif are involved with MTH463 cell toxicity. Furthermore, we established that purified MTH463 could degrade MS2 phage RNA, whereas purified MTH464 neutralized MTH463 activity in vitro. Our results indicate that the endonuclease toxin MTH463 (encoding a HEPN domain) and its cognate antitoxin MTH464 (encoding the MNT domain) may act as a type II TA system in M. thermautotropicus ΔH. This study provides initial and essential information studying TA system functions, primarily archaea HEPN-MNT family.
Collapse
Affiliation(s)
- Wonho Choi
- Bio-Evaluation Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju, 28116, Republic of Korea
- 4D Convergence Technology Institute (National Key Technology Institute in University), Korea National University of Transportation, Jungpyeong, 27909, Republic of Korea
| | - Anoth Maharjan
- Bio-Evaluation Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju, 28116, Republic of Korea
| | - Hae Gang Im
- BIORCHESTRA Co., LTD., Daejeon, 34013, Republic of Korea
| | - Ji-Young Park
- Bio-Evaluation Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju, 28116, Republic of Korea
| | - Jong-Tae Park
- Department of Food Science and Technology, Chungnam National University, Daejeon, 34134, Republic of Korea.
| | - Jung-Ho Park
- Bio-Evaluation Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju, 28116, Republic of Korea.
| |
Collapse
|
15
|
Sonika S, Singh S, Mishra S, Verma S. Toxin-antitoxin systems in bacterial pathogenesis. Heliyon 2023; 9:e14220. [PMID: 37101643 PMCID: PMC10123168 DOI: 10.1016/j.heliyon.2023.e14220] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023] Open
Abstract
Toxin-Antitoxin (TA) systems are abundant in prokaryotes and play an important role in various biological processes such as plasmid maintenance, phage inhibition, stress response, biofilm formation, and dormant persister cell generation. TA loci are abundant in pathogenic intracellular micro-organisms and help in their adaptation to the harsh host environment such as nutrient deprivation, oxidation, immune response, and antimicrobials. Several studies have reported the involvement of TA loci in establishing successful infection, intracellular survival, better colonization, adaptation to host stresses, and chronic infection. Overall, the TA loci play a crucial role in bacterial virulence and pathogenesis. Nonetheless, there are some controversies about the role of TA system in stress response, biofilm and persister formation. In this review, we describe the role of the TA systems in bacterial virulence. We discuss the important features of each type of TA system and the recent discoveries identifying key contributions of TA loci in bacterial pathogenesis.
Collapse
|
16
|
Li M, Guo N, Song G, Huang Y, Wang L, Zhang Y, Wang T. Type II Toxin-Antitoxin Systems in Pseudomonas aeruginosa. Toxins (Basel) 2023; 15:164. [PMID: 36828478 PMCID: PMC9966142 DOI: 10.3390/toxins15020164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/03/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
Toxin-antitoxin (TA) systems are typically composed of a stable toxin and a labile antitoxin; the latter counteracts the toxicity of the former under suitable conditions. TA systems are classified into eight types based on the nature and molecular modes of action of the antitoxin component so far. The 10 pairs of TA systems discovered and experimentally characterised in Pseudomonas aeruginosa are type II TA systems. Type II TA systems have various physiological functions, such as virulence and biofilm formation, protection host against antibiotics, persistence, plasmid maintenance, and prophage production. Here, we review the type II TA systems of P. aeruginosa, focusing on their biological functions and regulatory mechanisms, providing potential applications for the novel drug design.
Collapse
Affiliation(s)
| | | | | | | | | | - Yani Zhang
- Provincial Key Laboratory of Biotechnology, Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an 710069, China
| | - Tietao Wang
- Provincial Key Laboratory of Biotechnology, Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Sciences, Northwest University, Xi’an 710069, China
| |
Collapse
|
17
|
Mansour M, Giudice E, Xu X, Akarsu H, Bordes P, Guillet V, Bigot DJ, Slama N, D'urso G, Chat S, Redder P, Falquet L, Mourey L, Gillet R, Genevaux P. Substrate recognition and cryo-EM structure of the ribosome-bound TAC toxin of Mycobacterium tuberculosis. Nat Commun 2022; 13:2641. [PMID: 35552387 PMCID: PMC9098466 DOI: 10.1038/s41467-022-30373-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/27/2022] [Indexed: 11/16/2022] Open
Abstract
Toxins of toxin-antitoxin systems use diverse mechanisms to control bacterial growth. Here, we focus on the deleterious toxin of the atypical tripartite toxin-antitoxin-chaperone (TAC) system of Mycobacterium tuberculosis, whose inhibition requires the concerted action of the antitoxin and its dedicated SecB-like chaperone. We show that the TAC toxin is a bona fide ribonuclease and identify exact cleavage sites in mRNA targets on a transcriptome-wide scale in vivo. mRNA cleavage by the toxin occurs after the second nucleotide of the ribosomal A-site codon during translation, with a strong preference for CCA codons in vivo. Finally, we report the cryo-EM structure of the ribosome-bound TAC toxin in the presence of native M. tuberculosis cspA mRNA, revealing the specific mechanism by which the TAC toxin interacts with the ribosome and the tRNA in the P-site to cleave its mRNA target. Toxin-antitoxin systems are widespread in bacteria. Here the authors present structures of M. tuberculosis HigBTAC alone and bound to the ribosome in the presence of native cspA mRNA, shedding light on its mechanism of translation inhibition.
Collapse
Affiliation(s)
- Moise Mansour
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Emmanuel Giudice
- Institut de Génétique et Développement de Rennes (IGDR), UMR6290, Université de Rennes, CNRS, Rennes, France
| | - Xibing Xu
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Hatice Akarsu
- Department of Biology, University of Fribourg & Swiss Institute of Bioinformatics, Fribourg, Switzerland.,Institute of Veterinary Bacteriology, University of Bern, Bern, Switzerland
| | - Patricia Bordes
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Valérie Guillet
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Donna-Joe Bigot
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France.,Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Nawel Slama
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Gaetano D'urso
- Institut de Génétique et Développement de Rennes (IGDR), UMR6290, Université de Rennes, CNRS, Rennes, France
| | - Sophie Chat
- Institut de Génétique et Développement de Rennes (IGDR), UMR6290, Université de Rennes, CNRS, Rennes, France
| | - Peter Redder
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Laurent Falquet
- Department of Biology, University of Fribourg & Swiss Institute of Bioinformatics, Fribourg, Switzerland
| | - Lionel Mourey
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Reynald Gillet
- Institut de Génétique et Développement de Rennes (IGDR), UMR6290, Université de Rennes, CNRS, Rennes, France.
| | - Pierre Genevaux
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, Toulouse, France.
| |
Collapse
|
18
|
Abstract
Toxin-antitoxin systems are widespread in bacterial genomes. They are usually composed of two elements: a toxin that inhibits an essential cellular process and an antitoxin that counteracts its cognate toxin. In the past decade, a number of new toxin-antitoxin systems have been described, bringing new growth inhibition mechanisms to light as well as novel modes of antitoxicity. However, recent advances in the field profoundly questioned the role of these systems in bacterial physiology, stress response and antimicrobial persistence. This shifted the paradigm of the functions of toxin-antitoxin systems to roles related to interactions between hosts and their mobile genetic elements, such as viral defence or plasmid stability. In this Review, we summarize the recent progress in understanding the biology and evolution of these small genetic elements, and discuss how genomic conflicts could shape the diversification of toxin-antitoxin systems.
Collapse
|
19
|
Clostridioides difficile - phage relationship the RNA way. Curr Opin Microbiol 2021; 66:1-10. [PMID: 34922145 DOI: 10.1016/j.mib.2021.11.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 11/06/2021] [Accepted: 11/28/2021] [Indexed: 12/17/2022]
Abstract
Clostridioides difficile (formerly Clostridium difficile)-associated diarrhea is currently the most frequently occurring nosocomial diarrhea worldwide. During its infection cycle this pathogen needs to survive in phage-rich gut communities. Recent data strongly suggest that regulatory RNAs control gene expression in C. difficile and many of these RNAs appear to modulate C. difficile-phage interactions. Of the 200 regulatory RNAs identified by deep sequencing and targeted approaches, many function as antitoxins within type I toxin-antitoxin modules and CRISPR RNAs for anti-phage defenses. In this review, we discuss recent insights into the role of RNAs in modulating interactions between C. difficile and phages in light of intriguing data in other prokaryotes.
Collapse
|
20
|
Bordes P, Genevaux P. Control of Toxin-Antitoxin Systems by Proteases in Mycobacterium Tuberculosis. Front Mol Biosci 2021; 8:691399. [PMID: 34079824 PMCID: PMC8165232 DOI: 10.3389/fmolb.2021.691399] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/06/2021] [Indexed: 12/30/2022] Open
Abstract
Toxin-antitoxin (TA) systems are small genetic elements composed of a noxious toxin and a counteracting cognate antitoxin. Although they are widespread in bacterial chromosomes and in mobile genetic elements, their cellular functions and activation mechanisms remain largely unknown. It has been proposed that toxin activation or expression of the TA operon could rely on the degradation of generally less stable antitoxins by cellular proteases. The resulting active toxin would then target essential cellular processes and inhibit bacterial growth. Although interplay between proteases and TA systems has been observed, evidences for such activation cycle are very limited. Herein, we present an overview of the current knowledge on TA recognition by proteases with a main focus on the major human pathogen Mycobacterium tuberculosis, which harbours multiple TA systems (over 80), the essential AAA + stress proteases, ClpC1P1P2 and ClpXP1P2, and the Pup-proteasome system.
Collapse
Affiliation(s)
- Patricia Bordes
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Pierre Genevaux
- Laboratoire de Microbiologie et de Génétique Moléculaires, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| |
Collapse
|
21
|
De Bruyn P, Girardin Y, Loris R. Prokaryote toxin-antitoxin modules: Complex regulation of an unclear function. Protein Sci 2021; 30:1103-1113. [PMID: 33786944 PMCID: PMC8138530 DOI: 10.1002/pro.4071] [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: 02/26/2021] [Revised: 03/29/2021] [Accepted: 03/30/2021] [Indexed: 12/29/2022]
Abstract
Toxin–antitoxin (TA) modules are small operons in bacteria and archaea that encode a metabolic inhibitor (toxin) and a matching regulatory protein (antitoxin). While their biochemical activities are often well defined, their biological functions remain unclear. In Type II TA modules, the most common class, both toxin and antitoxin are proteins, and the antitoxin inhibits the biochemical activity of the toxin via complex formation with the toxin. The different TA modules vary significantly regarding structure and biochemical activity. Both regulation of protein activity by the antitoxin and regulation of transcription can be highly complex and sometimes show striking parallels between otherwise unrelated TA modules. Interplay between the multiple levels of regulation in the broader context of the cell as a whole is most likely required for optimum fine‐tuning of these systems. Thus, TA modules can go through great lengths to prevent activation and to reverse accidental activation, in agreement with recent in vivo data. These complex mechanisms seem at odds with the lack of a clear biological function.
Collapse
Affiliation(s)
- Pieter De Bruyn
- VIB-VUB Center for Structural Biology, Vrije Universiteit Brussel and Vlaams Instituut voor Biotechnologie, Brussels, Belgium
| | - Yana Girardin
- VIB-VUB Center for Structural Biology, Vrije Universiteit Brussel and Vlaams Instituut voor Biotechnologie, Brussels, Belgium
| | - Remy Loris
- VIB-VUB Center for Structural Biology, Vrije Universiteit Brussel and Vlaams Instituut voor Biotechnologie, Brussels, Belgium
| |
Collapse
|