1
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Deep A, Liang Q, Enustun E, Pogliano J, Corbett KD. Architecture and activation mechanism of the bacterial PARIS defence system. Nature 2024:10.1038/s41586-024-07772-8. [PMID: 39112702 DOI: 10.1038/s41586-024-07772-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 07/02/2024] [Indexed: 08/17/2024]
Abstract
Bacteria and their viruses (bacteriophages or phages) are engaged in an intense evolutionary arms race1-5. While the mechanisms of many bacterial antiphage defence systems are known1, how these systems avoid toxicity outside infection yet activate quickly after infection is less well understood. Here we show that the bacterial phage anti-restriction-induced system (PARIS) operates as a toxin-antitoxin system, in which the antitoxin AriA sequesters and inactivates the toxin AriB until triggered by the T7 phage counterdefence protein Ocr. Using cryo-electron microscopy, we show that AriA is related to SMC-family ATPases but assembles into a distinctive homohexameric complex through two oligomerization interfaces. In uninfected cells, the AriA hexamer binds to up to three monomers of AriB, maintaining them in an inactive state. After Ocr binding, the AriA hexamer undergoes a structural rearrangement, releasing AriB and allowing it to dimerize and activate. AriB is a toprim/OLD-family nuclease, the activation of which arrests cell growth and inhibits phage propagation by globally inhibiting protein translation through specific cleavage of a lysine tRNA. Collectively, our findings reveal the intricate molecular mechanisms of a bacterial defence system triggered by a phage counterdefence protein, and highlight how an SMC-family ATPase has been adapted as a bacterial infection sensor.
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Affiliation(s)
- Amar Deep
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA.
| | - Qishan Liang
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
| | - Eray Enustun
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA, USA
| | - Joe Pogliano
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA, USA
| | - Kevin D Corbett
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA.
- Department of Molecular Biology, University of California, San Diego, La Jolla, CA, USA.
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2
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Mets T, Kurata T, Ernits K, Johansson MJO, Craig SZ, Evora GM, Buttress JA, Odai R, Wallant KC, Nakamoto JA, Shyrokova L, Egorov AA, Doering CR, Brodiazhenko T, Laub MT, Tenson T, Strahl H, Martens C, Harms A, Garcia-Pino A, Atkinson GC, Hauryliuk V. Mechanism of phage sensing and restriction by toxin-antitoxin-chaperone systems. Cell Host Microbe 2024; 32:1059-1073.e8. [PMID: 38821063 DOI: 10.1016/j.chom.2024.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/10/2024] [Accepted: 05/07/2024] [Indexed: 06/02/2024]
Abstract
Toxin-antitoxins (TAs) are prokaryotic two-gene systems composed of a toxin neutralized by an antitoxin. Toxin-antitoxin-chaperone (TAC) systems additionally include a SecB-like chaperone that stabilizes the antitoxin by recognizing its chaperone addiction (ChAD) element. TACs mediate antiphage defense, but the mechanisms of viral sensing and restriction are unexplored. We identify two Escherichia coli antiphage TAC systems containing host inhibition of growth (HigBA) and CmdTA TA modules, HigBAC and CmdTAC. HigBAC is triggered through recognition of the gpV major tail protein of phage λ. Chaperone HigC recognizes gpV and ChAD via analogous aromatic molecular patterns, with gpV outcompeting ChAD to trigger toxicity. For CmdTAC, the CmdT ADP-ribosyltransferase toxin modifies mRNA to halt protein synthesis and limit phage propagation. Finally, we establish the modularity of TACs by creating a hybrid broad-spectrum antiphage system combining the CmdTA TA warhead with a HigC chaperone phage sensor. Collectively, these findings reveal the potential of TAC systems in broad-spectrum antiphage defense.
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Affiliation(s)
- Toomas Mets
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; University of Tartu, Institute of Technology, 50411 Tartu, Estonia
| | - Tatsuaki Kurata
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Karin Ernits
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Marcus J O Johansson
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Sophie Z Craig
- Cellular and Molecular Microbiology (CM2), Faculté des Sciences, Université Libre de Bruxelles (ULB), Campus La Plaine, Building BC, Room 1C4203, Boulevard du Triomphe, 1050 Brussels, Belgium
| | - Gabriel Medina Evora
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; Cellular and Molecular Microbiology (CM2), Faculté des Sciences, Université Libre de Bruxelles (ULB), Campus La Plaine, Building BC, Room 1C4203, Boulevard du Triomphe, 1050 Brussels, Belgium
| | - Jessica A Buttress
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Roni Odai
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Kyo Coppieters't Wallant
- Centre for Structural Biology and Bioinformatics, Université Libre de Bruxelles (ULB), Boulevard du Triomphe, Building BC, 1050 Bruxelles, Belgium
| | - Jose A Nakamoto
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Lena Shyrokova
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Artyom A Egorov
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | | | | | - Michael T Laub
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Tanel Tenson
- University of Tartu, Institute of Technology, 50411 Tartu, Estonia
| | - Henrik Strahl
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Chloe Martens
- Centre for Structural Biology and Bioinformatics, Université Libre de Bruxelles (ULB), Boulevard du Triomphe, Building BC, 1050 Bruxelles, Belgium
| | - Alexander Harms
- ETH Zurich, Institute of Food, Nutrition and Health, 8092 Zürich, Switzerland
| | - Abel Garcia-Pino
- Cellular and Molecular Microbiology (CM2), Faculté des Sciences, Université Libre de Bruxelles (ULB), Campus La Plaine, Building BC, Room 1C4203, Boulevard du Triomphe, 1050 Brussels, Belgium.
| | - Gemma C Atkinson
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; Virus Centre, Lund University, Lund, Sweden.
| | - Vasili Hauryliuk
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden; University of Tartu, Institute of Technology, 50411 Tartu, Estonia; Virus Centre, Lund University, Lund, Sweden; Science for Life Laboratory, Lund, Sweden.
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3
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Dominguez-Molina L, Kurata T, Cepauskas A, Echemendia-Blanco D, Zedek S, Talavera-Perez A, Atkinson GC, Hauryliuk V, Garcia-Pino A. Mechanisms of neutralization of toxSAS from toxin-antitoxin modules. Nat Chem Biol 2024:10.1038/s41589-024-01630-4. [PMID: 38834893 DOI: 10.1038/s41589-024-01630-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 04/22/2024] [Indexed: 06/06/2024]
Abstract
Toxic small alarmone synthetase (toxSAS) enzymes constitute a family of bacterial effectors present in toxin-antitoxin and secretion systems. toxSASs act through either translation inhibition mediated by pyrophosphorylation of transfer RNA (tRNA) CCA ends or synthesis of the toxic alarmone adenosine pentaphosphate ((pp)pApp) and adenosine triphosphate (ATP) depletion, exemplified by FaRel2 and FaRel, respectively. However, structural bases of toxSAS neutralization are missing. Here we show that the pseudo-Zn2+ finger domain (pZFD) of the ATfaRel2 antitoxin precludes access of ATP to the pyrophosphate donor site of the FaRel2 toxin, without affecting recruitment of the tRNA pyrophosphate acceptor. By contrast, (pp)pApp-producing toxSASs are inhibited by Tis1 antitoxin domains though occlusion of the pyrophosphate acceptor-binding site. Consequently, the auxiliary pZFD of AT2faRel is dispensable for FaRel neutralization. Collectively, our study establishes the general principles of toxSAS inhibition by structured antitoxin domains, with the control strategy directly coupled to toxSAS substrate specificity.
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Affiliation(s)
- Lucia Dominguez-Molina
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - Tatsuaki Kurata
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Albinas Cepauskas
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - Dannele Echemendia-Blanco
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - Safia Zedek
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - Ariel Talavera-Perez
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Brussels, Belgium
| | - Gemma C Atkinson
- Department of Experimental Medical Science, Lund University, Lund, Sweden.
| | - Vasili Hauryliuk
- Department of Experimental Medical Science, Lund University, Lund, Sweden.
- Faculty of Science and Technology, University of Tartu Institute of Technology, Tartu, Estonia.
- Science for Life Laboratory, Lund, Sweden.
| | - Abel Garcia-Pino
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Brussels, Belgium.
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4
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Geller AM, Shalom M, Zlotkin D, Blum N, Levy A. Identification of type VI secretion system effector-immunity pairs using structural bioinformatics. Mol Syst Biol 2024; 20:702-718. [PMID: 38658795 PMCID: PMC11148199 DOI: 10.1038/s44320-024-00035-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/24/2024] [Accepted: 04/09/2024] [Indexed: 04/26/2024] Open
Abstract
The type VI secretion system (T6SS) is an important mediator of microbe-microbe and microbe-host interactions. Gram-negative bacteria use the T6SS to inject T6SS effectors (T6Es), which are usually proteins with toxic activity, into neighboring cells. Antibacterial effectors have cognate immunity proteins that neutralize self-intoxication. Here, we applied novel structural bioinformatic tools to perform systematic discovery and functional annotation of T6Es and their cognate immunity proteins from a dataset of 17,920 T6SS-encoding bacterial genomes. Using structural clustering, we identified 517 putative T6E families, outperforming sequence-based clustering. We developed a logistic regression model to reliably quantify protein-protein interaction of new T6E-immunity pairs, yielding candidate immunity proteins for 231 out of the 517 T6E families. We used sensitive structure-based annotation which yielded functional annotations for 51% of the T6E families, again outperforming sequence-based annotation. Next, we validated four novel T6E-immunity pairs using basic experiments in E. coli. In particular, we showed that the Pfam domain DUF3289 is a homolog of Colicin M and that DUF943 acts as its cognate immunity protein. Furthermore, we discovered a novel T6E that is a structural homolog of SleB, a lytic transglycosylase, and identified a specific glutamate that acts as its putative catalytic residue. Overall, this study applies novel structural bioinformatic tools to T6E-immunity pair discovery, and provides an extensive database of annotated T6E-immunity pairs.
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Affiliation(s)
- Alexander M Geller
- Department of Plant Pathology and Microbiology, The Institute of Environmental Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Maor Shalom
- Department of Plant Pathology and Microbiology, The Institute of Environmental Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - David Zlotkin
- Department of Plant Pathology and Microbiology, The Institute of Environmental Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Noam Blum
- Department of Plant Pathology and Microbiology, The Institute of Environmental Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Asaf Levy
- Department of Plant Pathology and Microbiology, The Institute of Environmental Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel.
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5
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Zhang S, Sun A, Qian JM, Lin S, Xing W, Yang Y, Zhu HZ, Zhou XY, Guo YS, Liu Y, Meng Y, Jin SL, Song W, Li CP, Li Z, Jin S, Wang JH, Dong MQ, Gao C, Chen C, Bai Y, Liu JJG. Pro-CRISPR PcrIIC1-associated Cas9 system for enhanced bacterial immunity. Nature 2024; 630:484-492. [PMID: 38811729 DOI: 10.1038/s41586-024-07486-x] [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: 10/13/2023] [Accepted: 04/29/2024] [Indexed: 05/31/2024]
Abstract
The CRISPR system is an adaptive immune system found in prokaryotes that defends host cells against the invasion of foreign DNA1. As part of the ongoing struggle between phages and the bacterial immune system, the CRISPR system has evolved into various types, each with distinct functionalities2. Type II Cas9 is the most extensively studied of these systems and has diverse subtypes. It remains uncertain whether members of this family can evolve additional mechanisms to counter viral invasions3,4. Here we identify 2,062 complete Cas9 loci, predict the structures of their associated proteins and reveal three structural growth trajectories for type II-C Cas9. We found that novel associated genes (NAGs) tended to be present within the loci of larger II-C Cas9s. Further investigation revealed that CbCas9 from Chryseobacterium species contains a novel β-REC2 domain, and forms a heterotetrameric complex with an NAG-encoded CRISPR-Cas-system-promoting (pro-CRISPR) protein of II-C Cas9 (PcrIIC1). The CbCas9-PcrIIC1 complex exhibits enhanced DNA binding and cleavage activity, broader compatibility for protospacer adjacent motif sequences, increased tolerance for mismatches and improved anti-phage immunity, compared with stand-alone CbCas9. Overall, our work sheds light on the diversity and 'growth evolutionary' trajectories of II-C Cas9 proteins at the structural level, and identifies many NAGs-such as PcrIIC1, which serves as a pro-CRISPR factor to enhance CRISPR-mediated immunity.
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Affiliation(s)
- Shouyue Zhang
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Ao Sun
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jing-Mei Qian
- State Key Laboratory of Plant Genomics, CAS-JIC Centre of Excellence for Plant and Microbial Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Shuo Lin
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Wenjing Xing
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yun Yang
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Han-Zhou Zhu
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xin-Yi Zhou
- State Key Laboratory of Plant Genomics, CAS-JIC Centre of Excellence for Plant and Microbial Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yan-Shuo Guo
- State Key Laboratory of Plant Genomics, CAS-JIC Centre of Excellence for Plant and Microbial Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yun Liu
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Yu Meng
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Shu-Lin Jin
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Wenhao Song
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Cheng-Ping Li
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Zhaofu Li
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Shuai Jin
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Genome Editing, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Jian-Hua Wang
- National Institute of Biological Sciences, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| | - Caixia Gao
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Plant Cell and Chromosome Engineering, Center for Genome Editing, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Chunlai Chen
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.
| | - Yang Bai
- State Key Laboratory of Plant Genomics, CAS-JIC Centre of Excellence for Plant and Microbial Sciences, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China.
- Peking-Tsinghua Center for Life Sciences, College of Life Sciences, Peking University, Beijing, China.
| | - Jun-Jie Gogo Liu
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China.
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6
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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.
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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
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7
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Gerdes K. Diverse genetic contexts of HicA toxin domains propose a role in anti-phage defense. mBio 2024; 15:e0329323. [PMID: 38236063 PMCID: PMC10865869 DOI: 10.1128/mbio.03293-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 12/11/2023] [Indexed: 01/19/2024] Open
Abstract
Toxin-antitoxin (TA) modules are prevalent in prokaryotic genomes, often in substantial numbers. For instance, the Mycobacterium tuberculosis genome alone harbors close to 100 TA modules, half of which belong to a singular type. Traditionally ascribed multiple biological roles, recent insights challenge these notions and instead indicate a predominant function in phage defense. TAs are often located within Defense Islands, genomic regions that encode various defense systems. The analysis of genes within Defense Islands has unveiled a wide array of systems, including TAs that serve in anti-phage defense. Prokaryotic cells are equipped with anti-phage Viperins that, analogous to their mammalian counterparts, inhibit viral RNA transcription. Additionally, bacterial Structural Maintenance of Chromosome (SMC) proteins combat plasmid intrusion by recognizing foreign DNA signatures. This study undertakes a comprehensive bioinformatics analysis of genetic elements encoding the HicA double-stranded RNA-binding domain, complemented by protein structure modeling. The HicA toxin domains are found in at least 14 distinct contexts and thus exhibit a remarkable genetic diversity. Traditional bicistronic TA operons represent eight of these contexts, while four are characterized by monocistronic operons encoding fused HicA domains. Two contexts involve hicA adjacent to genes that encode bacterial Viperins. Notably, genes encoding RelE toxins are also adjacent to Viperin genes in some instances. This configuration hints at a synergistic enhancement of Viperin-mediated anti-phage action by HicA and RelE toxins. The discovery of a HicA domain merged with an SMC domain is compelling, prompting further investigation into its potential roles.IMPORTANCEProkaryotic organisms harbor a multitude of toxin-antitoxin (TA) systems, which have long puzzled scientists as "genes in search for a function." Recent scientific advancements have shed light on the primary role of TAs as anti-phage defense mechanisms. To gain an overview of TAs it is important to analyze their genetic contexts that can give hints on function and guide future experimental inquiries. This article describes a thorough bioinformatics examination of genes encoding the HicA toxin domain, revealing its presence in no fewer than 14 unique genetic arrangements. Some configurations notably align with anti-phage activities, underscoring potential roles in microbial immunity. These insights robustly reinforce the hypothesis that HicA toxins are integral components of the prokaryotic anti-phage defense repertoire. The elucidation of these genetic contexts not only advances our understanding of TAs but also contributes to a paradigm shift in how we perceive their functionality within the microbial world.
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Affiliation(s)
- Kenn Gerdes
- Kenn Gerdes is an independent researcher with the residence, Voldmestergade, Copenhagen, Denmark
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8
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Burman N, Belukhina S, Depardieu F, Wilkinson RA, Skutel M, Santiago-Frangos A, Graham AB, Livenskyi A, Chechenina A, Morozova N, Zahl T, Henriques WS, Buyukyoruk M, Rouillon C, Shyrokova L, Kurata T, Hauryliuk V, Severinov K, Groseille J, Thierry A, Koszul R, Tesson F, Bernheim A, Bikard D, Wiedenheft B, Isaev A. Viral proteins activate PARIS-mediated tRNA degradation and viral tRNAs rescue infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.02.573894. [PMID: 38260645 PMCID: PMC10802454 DOI: 10.1101/2024.01.02.573894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Viruses compete with each other for limited cellular resources, and some viruses deliver defense mechanisms that protect the host from competing genetic parasites. PARIS is a defense system, often encoded in viral genomes, that is composed of a 53 kDa ABC ATPase (AriA) and a 35 kDa TOPRIM nuclease (AriB). Here we show that AriA and AriB assemble into a 425 kDa supramolecular immune complex. We use cryo-EM to determine the structure of this complex which explains how six molecules of AriA assemble into a propeller-shaped scaffold that coordinates three subunits of AriB. ATP-dependent detection of foreign proteins triggers the release of AriB, which assembles into a homodimeric nuclease that blocks infection by cleaving the host tRNALys. Phage T5 subverts PARIS immunity through expression of a tRNALys variant that prevents PARIS-mediated cleavage, and thereby restores viral infection. Collectively, these data explain how AriA functions as an ATP-dependent sensor that detects viral proteins and activates the AriB toxin. PARIS is one of an emerging set of immune systems that form macromolecular complexes for the recognition of foreign proteins, rather than foreign nucleic acids.
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Affiliation(s)
- Nathaniel Burman
- Montana State University, Bozeman, Department of Microbiology and Cell Biology, 59715 Montana, USA
| | - Svetlana Belukhina
- Skolkovo Institute of Science and Technology, Center for Molecular and Cellular Biology, Moscow, Russia
| | - Florence Depardieu
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Synthetic Biology, 75015 Paris, France
| | - Royce A. Wilkinson
- Montana State University, Bozeman, Department of Microbiology and Cell Biology, 59715 Montana, USA
| | - Mikhail Skutel
- Skolkovo Institute of Science and Technology, Center for Molecular and Cellular Biology, Moscow, Russia
| | - Andrew Santiago-Frangos
- Montana State University, Bozeman, Department of Microbiology and Cell Biology, 59715 Montana, USA
| | - Ava B. Graham
- Montana State University, Bozeman, Department of Microbiology and Cell Biology, 59715 Montana, USA
| | - Alexei Livenskyi
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Anna Chechenina
- Skolkovo Institute of Science and Technology, Center for Molecular and Cellular Biology, Moscow, Russia
| | - Natalia Morozova
- Peter the Great St Petersburg State Polytechnic University, St. Petersburg, Russia
| | - Trevor Zahl
- Montana State University, Bozeman, Department of Microbiology and Cell Biology, 59715 Montana, USA
| | - William S. Henriques
- Montana State University, Bozeman, Department of Microbiology and Cell Biology, 59715 Montana, USA
| | - Murat Buyukyoruk
- Montana State University, Bozeman, Department of Microbiology and Cell Biology, 59715 Montana, USA
| | - Christophe Rouillon
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Synthetic Biology, 75015 Paris, France
| | - Lena Shyrokova
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Tatsuaki Kurata
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
| | - Vasili Hauryliuk
- Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
- Virus Centre, Lund University, Lund, Sweden
- Science for Life Laboratory, Lund, Sweden
| | | | - Justine Groseille
- Institut Pasteur, CNRS UMR 3525, Université Paris Cité, Unité Régulation Spatiale des Génomes, 75015 Paris, France
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
- Sorbonne Université, College Doctoral
| | - Agnès Thierry
- Institut Pasteur, CNRS UMR 3525, Université Paris Cité, Unité Régulation Spatiale des Génomes, 75015 Paris, France
| | - Romain Koszul
- Institut Pasteur, CNRS UMR 3525, Université Paris Cité, Unité Régulation Spatiale des Génomes, 75015 Paris, France
| | - Florian Tesson
- Institut Pasteur, Université Paris Cité, Molecular Diversity of Microbes, 75015 Paris, France
| | - Aude Bernheim
- Institut Pasteur, Université Paris Cité, Molecular Diversity of Microbes, 75015 Paris, France
| | - David Bikard
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Synthetic Biology, 75015 Paris, France
| | - Blake Wiedenheft
- Montana State University, Bozeman, Department of Microbiology and Cell Biology, 59715 Montana, USA
| | - Artem Isaev
- Skolkovo Institute of Science and Technology, Center for Molecular and Cellular Biology, Moscow, Russia
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9
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Patel KM, Seed KD. Sporadic phage defense in epidemic Vibrio cholerae mediated by the toxin-antitoxin system DarTG is countered by a phage-encoded antitoxin mimic. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.14.571748. [PMID: 38168179 PMCID: PMC10760071 DOI: 10.1101/2023.12.14.571748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Bacteria and their viral predators (phages) are constantly evolving to subvert one another. Many bacterial immune systems that inhibit phages are encoded on mobile genetic elements that can be horizontally transmitted to diverse bacteria. Despite the pervasive appearance of immune systems in bacteria, it is not often known if these immune systems function against phages that the host encounters in nature. Additionally, there are limited examples demonstrating how these phages counter-adapt to such immune systems. Here, we identify clinical isolates of the global pathogen Vibrio cholerae harboring a novel genetic element encoding the bacterial immune system DarTG and reveal the immune system's impact on the co-circulating lytic phage ICP1. We show that DarTG inhibits ICP1 genome replication, thus preventing ICP1 plaquing. We further characterize the conflict between DarTG-mediated defense and ICP1 by identifying an ICP1-encoded protein that counters DarTG and allows ICP1 progeny production. Finally, we identify this protein as a functional antitoxin that abrogates the toxin DarT likely through direct interactions. Following the detection of the DarTG system in clinical V. cholerae isolates, we observed a rise in ICP1 isolates with the functional antitoxin. These data highlight the use of surveillance of V. cholerae and its lytic phages to understand the co-evolutionary arms race between bacteria and their phages in nature.
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Affiliation(s)
- Kishen M Patel
- Infectious Diseases and Immunity Graduate Group, School of Public Health, University of California, Berkeley, Berkeley, CA, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
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