1
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Bravo JPK, Ramos DA, Fregoso Ocampo R, Ingram C, Taylor DW. Plasmid targeting and destruction by the DdmDE bacterial defence system. Nature 2024; 630:961-967. [PMID: 38740055 DOI: 10.1038/s41586-024-07515-9] [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: 09/13/2023] [Accepted: 05/03/2024] [Indexed: 05/16/2024]
Abstract
Although eukaryotic Argonautes have a pivotal role in post-transcriptional gene regulation through nucleic acid cleavage, some short prokaryotic Argonaute variants (pAgos) rely on auxiliary nuclease factors for efficient foreign DNA degradation1. Here we reveal the activation pathway of the DNA defence module DdmDE system, which rapidly eliminates small, multicopy plasmids from the Vibrio cholerae seventh pandemic strain (7PET)2. Through a combination of cryo-electron microscopy, biochemistry and in vivo plasmid clearance assays, we demonstrate that DdmE is a catalytically inactive, DNA-guided, DNA-targeting pAgo with a distinctive insertion domain. We observe that the helicase-nuclease DdmD transitions from an autoinhibited, dimeric complex to a monomeric state upon loading of single-stranded DNA targets. Furthermore, the complete structure of the DdmDE-guide-target handover complex provides a comprehensive view into how DNA recognition triggers processive plasmid destruction. Our work establishes a mechanistic foundation for how pAgos utilize ancillary factors to achieve plasmid clearance, and provides insights into anti-plasmid immunity in bacteria.
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Affiliation(s)
- Jack P K Bravo
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA.
- Institute of Science and Technology Austria (ISTA), Klosterneuberg, Austria.
| | - Delisa A Ramos
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | | | - Caiden Ingram
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - David W Taylor
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, USA
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX, USA
- Livestrong Cancer Institutes, Dell Medical School, Austin, TX, USA
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2
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Oshiro RT, Dunham DT, Seed KD. The vibriophage-encoded inhibitor OrbA abrogates BREX-mediated defense through the ATPase BrxC. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.09.593382. [PMID: 38766029 PMCID: PMC11100822 DOI: 10.1101/2024.05.09.593382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Bacteria and phages are locked in a co-evolutionary arms race where each entity evolves mechanisms to restrict the proliferation of the other. Phage-encoded defense inhibitors have proven powerful tools to interrogate how defense systems function. A relatively common defense system is BREX (Bacteriophage exclusion); however, how BREX functions to restrict phage infection remains poorly understood. A BREX system encoded by the SXT integrative and conjugative element, Vch Ind5, was recently identified in Vibrio cholerae , the causative agent of the diarrheal disease cholera. The lytic phage ICP1 that co-circulates with V. cholerae encodes the BREX inhibitor OrbA, but how OrbA inhibits BREX is unclear. Here, we determine that OrbA inhibits BREX using a unique mechanism from known BREX inhibitors by directly binding to the BREX component BrxC. BrxC has a functional ATPase domain that, when mutated, not only disrupts BrxC function but also alters how BrxC multimerizes. Furthermore, we find that OrbA binding disrupts BrxC-BrxC interactions. We determine that OrbA cannot bind BrxC encoded by the distantly related BREX system encoded by the SXT Vch Ban9, and thus fails to inhibit this BREX system that also circulates in epidemic V. cholerae . Lastly, we find that homologs of the Vch Ind5 BrxC are more diverse than the homologs of the Vch Ban9 BrxC. These data provide new insight into the function of the BrxC ATPase and highlight how phage-encoded inhibitors can disrupt phage defense systems using different mechanisms. Importance With renewed interest in phage therapy to combat antibiotic-resistant pathogens, understanding the mechanisms bacteria use to defend themselves against phages and the counter-strategies phages evolve to inhibit defenses is paramount. Bacteriophage exclusion (BREX) is a common defense system with few known inhibitors. Here, we probe how the vibriophage-encoded inhibitor OrbA inhibits the BREX system of Vibrio cholerae , the causative agent of the diarrheal disease cholera. By interrogating OrbA function, we have begun to understand the importance and function of a BREX component. Our results demonstrate the importance of identifying inhibitors against defense systems, as they are powerful tools for dissecting defense activity and can inform strategies to increase the efficacy of some phage therapies.
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3
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Agapov A, Baker KS, Bedekar P, Bhatia RP, Blower TR, Brockhurst MA, Brown C, Chong CE, Fothergill JL, Graham S, Hall JP, Maestri A, McQuarrie S, Olina A, Pagliara S, Recker M, Richmond A, Shaw SJ, Szczelkun MD, Taylor TB, van Houte S, Went SC, Westra ER, White MF, Wright R. Multi-layered genome defences in bacteria. Curr Opin Microbiol 2024; 78:102436. [PMID: 38368839 DOI: 10.1016/j.mib.2024.102436] [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: 11/14/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/20/2024]
Abstract
Bacteria have evolved a variety of defence mechanisms to protect against mobile genetic elements, including restriction-modification systems and CRISPR-Cas. In recent years, dozens of previously unknown defence systems (DSs) have been discovered. Notably, diverse DSs often coexist within the same genome, and some co-occur at frequencies significantly higher than would be expected by chance, implying potential synergistic interactions. Recent studies have provided evidence of defence mechanisms that enhance or complement one another. Here, we review the interactions between DSs at the mechanistic, regulatory, ecological and evolutionary levels.
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Affiliation(s)
- Aleksei Agapov
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | - Kate S Baker
- Department of Genetics, University of Cambridge, CB2 3EH, UK
| | - Paritosh Bedekar
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | - Rama P Bhatia
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | - Tim R Blower
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK
| | - Michael A Brockhurst
- Division of Evolution, Infection and Genomics, School of Biological Sciences, University of Manchester, Dover Street, Manchester M13 9PT, UK
| | - Cooper Brown
- School of Biology, University of St Andrews, St Andrews KY16 9ST, UK
| | | | - Joanne L Fothergill
- Dept of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, UK
| | - Shirley Graham
- School of Biology, University of St Andrews, St Andrews KY16 9ST, UK
| | - James Pj Hall
- Dept of Evolution, Ecology and Behaviour, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, L69 7ZB, UK
| | - Alice Maestri
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | - Stuart McQuarrie
- School of Biology, University of St Andrews, St Andrews KY16 9ST, UK
| | - Anna Olina
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | | | - Mario Recker
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | - Anna Richmond
- ESI, Centre for Ecology and Conservation, University of Exeter, UK
| | - Steven J Shaw
- DNA-Protein Interactions Unit, School of Biochemistry, University of Bristol, Bristol BS6 7YB, UK
| | - Mark D Szczelkun
- DNA-Protein Interactions Unit, School of Biochemistry, University of Bristol, Bristol BS6 7YB, UK
| | - Tiffany B Taylor
- Milner Centre for Evolution, Department of Life Sciences, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | | | - Sam C Went
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK
| | - Edze R Westra
- ESI, Centre for Ecology and Conservation, University of Exeter, UK.
| | - Malcolm F White
- School of Biology, University of St Andrews, St Andrews KY16 9ST, UK
| | - Rosanna Wright
- Division of Evolution, Infection and Genomics, School of Biological Sciences, University of Manchester, Dover Street, Manchester M13 9PT, UK
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4
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Beavogui A, Lacroix A, Wiart N, Poulain J, Delmont TO, Paoli L, Wincker P, Oliveira PH. The defensome of complex bacterial communities. Nat Commun 2024; 15:2146. [PMID: 38459056 PMCID: PMC10924106 DOI: 10.1038/s41467-024-46489-0] [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: 08/13/2023] [Accepted: 02/28/2024] [Indexed: 03/10/2024] Open
Abstract
Bacteria have developed various defense mechanisms to avoid infection and killing in response to the fast evolution and turnover of viruses and other genetic parasites. Such pan-immune system (defensome) encompasses a growing number of defense lines that include well-studied innate and adaptive systems such as restriction-modification, CRISPR-Cas and abortive infection, but also newly found ones whose mechanisms are still poorly understood. While the abundance and distribution of defense systems is well-known in complete and culturable genomes, there is a void in our understanding of their diversity and richness in complex microbial communities. Here we performed a large-scale in-depth analysis of the defensomes of 7759 high-quality bacterial population genomes reconstructed from soil, marine, and human gut environments. We observed a wide variation in the frequency and nature of the defensome among large phyla, which correlated with lifestyle, genome size, habitat, and geographic background. The defensome's genetic mobility, its clustering in defense islands, and genetic variability was found to be system-specific and shaped by the bacterial environment. Hence, our results provide a detailed picture of the multiple immune barriers present in environmentally distinct bacterial communities and set the stage for subsequent identification of novel and ingenious strategies of diversification among uncultivated microbes.
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Affiliation(s)
- Angelina Beavogui
- Génomique Métabolique, Genoscope, Institut François Jacob, Commissariat à l'Energie Atomique (CEA), CNRS, Université Evry, Université Paris-Saclay, 2 Rue Gaston Crémieux, 91057, Evry, France
| | - Auriane Lacroix
- Génomique Métabolique, Genoscope, Institut François Jacob, Commissariat à l'Energie Atomique (CEA), CNRS, Université Evry, Université Paris-Saclay, 2 Rue Gaston Crémieux, 91057, Evry, France
| | - Nicolas Wiart
- Genoscope, Institut François Jacob, CEA, Université Paris-Saclay, 2 Rue Gaston Crémieux, 91057, Evry, France
| | - Julie Poulain
- Génomique Métabolique, Genoscope, Institut François Jacob, Commissariat à l'Energie Atomique (CEA), CNRS, Université Evry, Université Paris-Saclay, 2 Rue Gaston Crémieux, 91057, Evry, France
- Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022 / Tara GOsee, Paris, France
| | - Tom O Delmont
- Génomique Métabolique, Genoscope, Institut François Jacob, Commissariat à l'Energie Atomique (CEA), CNRS, Université Evry, Université Paris-Saclay, 2 Rue Gaston Crémieux, 91057, Evry, France
- Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022 / Tara GOsee, Paris, France
| | - Lucas Paoli
- Department of Biology, Institute of Microbiology and Swiss Institute of Bioinformatics, ETH Zürich, Zürich, 8093, Switzerland
- Institut Pasteur, Université Paris Cité, INSERM U1284, Molecular Diversity of Microbes lab, Paris, France
| | - Patrick Wincker
- Génomique Métabolique, Genoscope, Institut François Jacob, Commissariat à l'Energie Atomique (CEA), CNRS, Université Evry, Université Paris-Saclay, 2 Rue Gaston Crémieux, 91057, Evry, France
- Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022 / Tara GOsee, Paris, France
| | - Pedro H Oliveira
- Génomique Métabolique, Genoscope, Institut François Jacob, Commissariat à l'Energie Atomique (CEA), CNRS, Université Evry, Université Paris-Saclay, 2 Rue Gaston Crémieux, 91057, Evry, France.
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5
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Schumacher MA, Cannistraci E, Salinas R, Lloyd D, Messner E, Gozzi K. Structure of the WYL-domain containing transcription activator, DriD, in complex with ssDNA effector and DNA target site. Nucleic Acids Res 2024; 52:1435-1449. [PMID: 38142455 PMCID: PMC10853764 DOI: 10.1093/nar/gkad1198] [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: 09/19/2023] [Revised: 11/20/2023] [Accepted: 12/01/2023] [Indexed: 12/26/2023] Open
Abstract
Transcription regulators play central roles in orchestrating responses to changing environmental conditions. Recently the Caulobacter crescentus transcription activator DriD, which belongs to the newly defined WYL-domain family, was shown to regulate DNA damage responses independent of the canonical SOS pathway. However, the molecular mechanisms by which DriD and other WYL-regulators sense environmental signals and recognize DNA are not well understood. We showed DriD DNA-binding is triggered by its interaction with ssDNA, which is produced during DNA damage. Here we describe the structure of the full-length C. crescentus DriD bound to both target DNA and effector ssDNA. DriD consists of an N-terminal winged-HTH (wHTH) domain, linker region, three-helix bundle, WYL-domain and C-terminal WCX-dimer domain. Strikingly, DriD binds DNA using a novel, asymmetric DNA-binding mechanism that results from different conformations adopted by the linker. Although the linker does not touch DNA, our data show that contacts it makes with the wHTH are key for specific DNA binding. The structure indicates how ssDNA-effector binding to the WYL-domain impacts wHTH DNA binding. In conclusion, we present the first structure of a WYL-activator bound to both effector and target DNA. The structure unveils a unique, asymmetric DNA binding mode that is likely conserved among WYL-activators.
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Affiliation(s)
- Maria A Schumacher
- Department of Biochemistry, 307 Research Dr., Box 3711, Duke University Medical Center, Durham, NC 27710, USA
| | - Emily Cannistraci
- Department of Biochemistry, 307 Research Dr., Box 3711, Duke University Medical Center, Durham, NC 27710, USA
| | - Raul Salinas
- Department of Biochemistry, 307 Research Dr., Box 3711, Duke University Medical Center, Durham, NC 27710, USA
| | - Devin Lloyd
- 100 Edwin H Land Blvd, Rowland Institute at Harvard, Harvard University, Cambridge, Cambridge, MA 02142, USA
| | - Ella Messner
- 100 Edwin H Land Blvd, Rowland Institute at Harvard, Harvard University, Cambridge, Cambridge, MA 02142, USA
| | - Kevin Gozzi
- 100 Edwin H Land Blvd, Rowland Institute at Harvard, Harvard University, Cambridge, Cambridge, MA 02142, USA
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6
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Keller LML, Flattich K, Weber-Ban E. Novel WYL domain-containing transcriptional activator acts in response to genotoxic stress in rapidly growing mycobacteria. Commun Biol 2023; 6:1222. [PMID: 38042942 PMCID: PMC10693628 DOI: 10.1038/s42003-023-05592-6] [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: 07/05/2023] [Accepted: 11/15/2023] [Indexed: 12/04/2023] Open
Abstract
The WYL domain is a nucleotide-sensing module that controls the activity of transcription factors involved in the regulation of DNA damage response and phage defense mechanisms in bacteria. In this study, we investigated a WYL domain-containing transcription factor in Mycobacterium smegmatis that we termed stress-involved WYL domain-containing regulator (SiwR). We found that SiwR controls adjacent genes that belong to the DinB/YfiT-like putative metalloenzymes superfamily by upregulating their expression in response to various genotoxic stress conditions, including upon exposure to H2O2 or the natural antibiotic zeocin. We show that SiwR binds different forms of single-stranded DNA (ssDNA) with high affinity, primarily through its characteristic WYL domain. In combination with complementation studies of a M. smegmatis siwR deletion strain, our findings support a role of the WYL domains as signal-sensing activity switches of WYL domain-containing transcription factors (WYL TFs). Our study provides evidence that WYL TFs are involved in the adaptation of bacteria to changing environments and encountered stress conditions.
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Affiliation(s)
| | - Kim Flattich
- Institute of Molecular Biology and Biophysics, ETH Zurich, 8093, Zurich, Switzerland
| | - Eilika Weber-Ban
- Institute of Molecular Biology and Biophysics, ETH Zurich, 8093, Zurich, Switzerland.
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7
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Kelly A, Went SC, Mariano G, Shaw LP, Picton DM, Duffner SJ, Coates I, Herdman-Grant R, Gordeeva J, Drobiazko A, Isaev A, Lee YJ, Luyten Y, Morgan RD, Weigele P, Severinov K, Wenner N, Hinton JCD, Blower TR. Diverse Durham collection phages demonstrate complex BREX defense responses. Appl Environ Microbiol 2023; 89:e0062323. [PMID: 37668405 PMCID: PMC10537673 DOI: 10.1128/aem.00623-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/10/2023] [Indexed: 09/06/2023] Open
Abstract
Bacteriophages (phages) outnumber bacteria ten-to-one and cause infections at a rate of 1025 per second. The ability of phages to reduce bacterial populations makes them attractive alternative antibacterials for use in combating the rise in antimicrobial resistance. This effort may be hindered due to bacterial defenses such as Bacteriophage Exclusion (BREX) that have arisen from the constant evolutionary battle between bacteria and phages. For phages to be widely accepted as therapeutics in Western medicine, more must be understood about bacteria-phage interactions and the outcomes of bacterial phage defense. Here, we present the annotated genomes of 12 novel bacteriophage species isolated from water sources in Durham, UK, during undergraduate practical classes. The collection includes diverse species from across known phylogenetic groups. Comparative analyses of two novel phages from the collection suggest they may be founding members of a new genus. Using this Durham phage collection, we determined that particular BREX defense systems were likely to confer a varied degree of resistance against an invading phage. We concluded that the number of BREX target motifs encoded in the phage genome was not proportional to the degree of susceptibility. IMPORTANCE Bacteriophages have long been the source of tools for biotechnology that are in everyday use in molecular biology research laboratories worldwide. Phages make attractive new targets for the development of novel antimicrobials. While the number of phage genome depositions has increased in recent years, the expected bacteriophage diversity remains underrepresented. Here we demonstrate how undergraduates can contribute to the identification of novel phages and that a single City in England can provide ample phage diversity and the opportunity to find novel technologies. Moreover, we demonstrate that the interactions and intricacies of the interplay between bacterial phage defense systems such as Bacteriophage Exclusion (BREX) and phages are more complex than originally thought. Further work will be required in the field before the dynamic interactions between phages and bacterial defense systems are fully understood and integrated with novel phage therapies.
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Affiliation(s)
- Abigail Kelly
- Department of Biosciences, Durham University, Durham, UK
| | - Sam C. Went
- Department of Biosciences, Durham University, Durham, UK
| | - Giuseppina Mariano
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Liam P. Shaw
- Department of Biosciences, Durham University, Durham, UK
- Department of Biology, University of Oxford, Oxford, UK
| | | | | | - Isabel Coates
- Department of Biosciences, Durham University, Durham, UK
| | | | - Julia Gordeeva
- Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Alena Drobiazko
- Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Artem Isaev
- Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Yan-Jiun Lee
- New England Biolabs, Ipswich, Massachusetts, USA
| | | | | | | | | | - Nicolas Wenner
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Jay C. D. Hinton
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Tim R. Blower
- Department of Biosciences, Durham University, Durham, UK
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8
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Macdonald E, Wright R, Connolly JPR, Strahl H, Brockhurst M, van Houte S, Blower TR, Palmer T, Mariano G. The novel anti-phage system Shield co-opts an RmuC domain to mediate phage defense across Pseudomonas species. PLoS Genet 2023; 19:e1010784. [PMID: 37276233 DOI: 10.1371/journal.pgen.1010784] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 05/12/2023] [Indexed: 06/07/2023] Open
Abstract
Competitive bacteria-bacteriophage interactions have resulted in the evolution of a plethora of bacterial defense systems preventing phage propagation. In recent years, computational and bioinformatic approaches have underpinned the discovery of numerous novel bacterial defense systems. Anti-phage systems are frequently encoded together in genomic loci termed defense islands. Here we report the identification and characterisation of a novel anti-phage system, that we have termed Shield, which forms part of the Pseudomonas defensive arsenal. The Shield system comprises the core component ShdA, a membrane-bound protein harboring an RmuC domain. Heterologous production of ShdA alone is sufficient to mediate bacterial immunity against several phages. We demonstrate that Shield and ShdA confer population-level immunity and that they can also decrease transformation efficiency. We further show that ShdA homologues can degrade DNA in vitro and, when expressed in a heterologous host, can alter the organisation of the host chromosomal DNA. Use of comparative genomic approaches identified how Shield can be divided into four subtypes, three of which contain additional components that in some cases can negatively affect the activity of ShdA and/or provide additional lines of phage defense. Collectively, our results identify a new player within the Pseudomonas bacterial immunity arsenal that displays a novel mechanism of protection, and reveals a role for RmuC domains in phage defense.
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Affiliation(s)
- Elliot Macdonald
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Rosanna Wright
- Division of Evolution, Infection and Genomics, School of Biological Sciences, University of Manchester, Manchester, United Kingdom
| | - James P R Connolly
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Henrik Strahl
- Centre for Bacterial Cell Biology, Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Michael Brockhurst
- Division of Evolution, Infection and Genomics, School of Biological Sciences, University of Manchester, Manchester, United Kingdom
| | - Stineke van Houte
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, United Kingdom
| | - Tim R Blower
- Department of Biosciences, Durham University, Stockton Road, Durham, United Kingdom
| | - Tracy Palmer
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Giuseppina Mariano
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
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9
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Keller LM, Weber-Ban E. An emerging class of nucleic acid-sensing regulators in bacteria: WYL domain-containing proteins. Curr Opin Microbiol 2023; 74:102296. [PMID: 37027901 DOI: 10.1016/j.mib.2023.102296] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 04/09/2023]
Abstract
Transcriptional regulation plays a central role in adaptation to changing environments for all living organisms. Recently, proteins belonging to a novel widespread class of bacterial transcription factors have been characterized in mycobacteria and Proteobacteria. Those multidomain proteins carry a WYL domain that is almost exclusive to the domain of bacteria. WYL domain-containing proteins act as regulators in different cellular contexts, including the DNA damage response and bacterial immunity. WYL domains have an Sm-like fold with five antiparallel β-strands arranged into a β-sandwich preceded by an α-helix. A common feature of WYL domains is their ability to bind nucleic acids that regulate their activity. In this review, we discuss recent progress made toward the understanding of WYL domain-containing proteins as transcriptional regulators, their structural features, and molecular mechanisms, as well as their functional roles in bacterial physiology.
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Affiliation(s)
- Lena Ml Keller
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland
| | - Eilika Weber-Ban
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, 8093 Zurich, Switzerland.
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10
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Kelly A, Arrowsmith TJ, Went SC, Blower TR. Toxin-antitoxin systems as mediators of phage defence and the implications for abortive infection. Curr Opin Microbiol 2023; 73:102293. [PMID: 36958122 DOI: 10.1016/j.mib.2023.102293] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/14/2023] [Accepted: 02/21/2023] [Indexed: 03/25/2023]
Abstract
Bacteria have evolved a broad range of defence mechanisms to protect against infection by their viral parasites, bacteriophages (phages). Toxin-antitoxin (TA) systems are small loci found throughout bacteria and archaea that in some cases provide phage defence. The recent explosion in phage defence system discovery has identified multiple novel TA systems with antiphage activity. Due to inherent toxicity, TA systems are thought to mediate abortive infection (Abi), wherein the host cell dies in response to phage infection, removing the phage, and protecting clonal siblings. Recent studies, however, have uncovered molecular mechanisms by which TA systems are activated by phages, how they mediate toxicity, and how phages escape the defences. These new models reveal dazzling complexity in phage-host interactions and provide further evidence that TA systems do not in all cases inherently perform classic Abi, suggesting an evolved conceptual definition is required.
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Affiliation(s)
- Abigail Kelly
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK
| | - Tom J Arrowsmith
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK
| | - Sam C Went
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK
| | - Tim R Blower
- Department of Biosciences, Durham University, Stockton Road, Durham DH1 3LE, UK.
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11
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Structural Studies of Pif1 Helicases from Thermophilic Bacteria. Microorganisms 2023; 11:microorganisms11020479. [PMID: 36838444 PMCID: PMC9964779 DOI: 10.3390/microorganisms11020479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/03/2023] [Accepted: 02/08/2023] [Indexed: 02/17/2023] Open
Abstract
Pif1 proteins are DNA helicases belonging to Superfamily 1, with 5' to 3' directionality. They are conserved from bacteria to human and have been shown to be particularly important in eukaryotes for replication and nuclear and mitochondrial genome stability. However, Pif1 functions in bacteria are less known. While most Pif1 from mesophilic bacteria consist of the helicase core with limited N-terminal and C-terminal extensions, some Pif1 from thermophilic bacteria exhibit a C-terminal WYL domain. We solved the crystal structures of Pif1 helicase cores from thermophilic bacteria Deferribacter desulfuricans and Sulfurihydrogenibium sp. in apo and nucleotide bound form. We show that the N-terminal part is important for ligand binding. The full-length Pif1 helicase was predicted based on the Alphafold algorithm and the nucleic acid binding on the Pif1 helicase core and the WYL domain was modelled based on known crystallographic structures. The model predicts that amino acids in the domains 1A, WYL, and linker between the Helicase core and WYL are important for nucleic acid binding. Therefore, the N-terminal and C-terminal extensions may be necessary to strengthen the binding of nucleic acid on these Pif1 helicases. This may be an adaptation to thermophilic conditions.
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Tesson F, Bernheim A. Synergy and regulation of antiphage systems: toward the existence of a bacterial immune system? Curr Opin Microbiol 2023; 71:102238. [PMID: 36423502 DOI: 10.1016/j.mib.2022.102238] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 11/23/2022]
Abstract
Bacteria encode a vast repertoire of diverse antiphage defense systems. Recent studies revealed that different defense systems are often encoded within the same genome, raising the question of their possible interactions in a cell. Here, we review the known synergies and coregulations of antiphage systems. The emerging complexities suggest a potential existence of an additional level of organization of antiviral defense in prokaryotes. We argue that this organization could be compared with immune systems of animals and plants. We discuss this concept and explore what it could mean in bacteria.
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13
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Schmitz C, Madej M, Nowakowska Z, Cuppari A, Jacula A, Ksiazek M, Mikruta K, Wisniewski J, Pudelko-Malik N, Saran A, Zeytuni N, Mlynarz P, Lamont RJ, Usón I, Siksnys V, Potempa J, Solà M. Response regulator PorX coordinates oligonucleotide signalling and gene expression to control the secretion of virulence factors. Nucleic Acids Res 2022; 50:12558-12577. [PMID: 36464236 PMCID: PMC9757075 DOI: 10.1093/nar/gkac1103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/27/2022] [Accepted: 11/08/2022] [Indexed: 12/07/2022] Open
Abstract
The PglZ family of proteins belongs to the alkaline phosphatase superfamily, which consists of metallohydrolases with limited sequence identity but similar metal-coordination architectures in otherwise divergent active sites. Proteins with a well-defined PglZ domain are ubiquitous among prokaryotes as essential components of BREX phage defence systems and two-component systems (TCSs). Whereas other members of the alkaline phosphatase superfamily are well characterized, the activity, structure and biological function of PglZ family proteins remain unclear. We therefore investigated the structure and function of PorX, an orphan response regulator of the Porphyromonas gingivalis TCS containing a putative PglZ effector domain. The crystal structure of PorX revealed a canonical receiver domain, a helical bundle, and an unprecedented PglZ domain, similar to the general organization of the phylogenetically related BREX-PglZ proteins. The PglZ domain of PorX features an active site cleft suitable for large substrates. An extensive search for substrates revealed that PorX is a phosphodiesterase that acts on cyclic and linear oligonucleotides, including signalling molecules such as cyclic oligoadenylates. These results, combined with mutagenesis, biophysical and enzymatic analysis, suggest that PorX coordinates oligonucleotide signalling pathways and indirectly regulates gene expression to control the secretion of virulence factors.
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Affiliation(s)
- Claus Schmitz
- Department of Structural Biology, Molecular Biology Institute of Barcelona, CSIC, Barcelona Science Park, Barcelona E-08028, Spain
| | - Mariusz Madej
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków PL-30-387, Poland
| | - Zuzanna Nowakowska
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków PL-30-387, Poland
| | - Anna Cuppari
- Department of Structural Biology, Molecular Biology Institute of Barcelona, CSIC, Barcelona Science Park, Barcelona E-08028, Spain
| | - Anna Jacula
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków PL-30-387, Poland
| | - Miroslaw Ksiazek
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków PL-30-387, Poland
| | - Katarzyna Mikruta
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków PL-30-387, Poland
| | - Jerzy Wisniewski
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wroclaw PL-50-370, Poland
| | - Natalia Pudelko-Malik
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wroclaw PL-50-370, Poland
| | - Anshu Saran
- Department of Anatomy and Cell Biology, McGill University, Montréal, Quebec H3A 0C7, Canada
| | - Natalie Zeytuni
- Department of Anatomy and Cell Biology, McGill University, Montréal, Quebec H3A 0C7, Canada
| | - Piotr Mlynarz
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wroclaw PL-50-370, Poland
| | - Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY 40202, USA
| | - Isabel Usón
- Department of Structural Biology, Molecular Biology Institute of Barcelona, CSIC, Barcelona Science Park, Barcelona E-08028, Spain
- ICREA Institució Catalana de Recerca i Estudis Avançats, Barcelona E-08010, Spain
| | - Virginijus Siksnys
- Institute of Biotechnology, Vilnius University, Vilnius 10257, Lithuania
| | - Jan Potempa
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków PL-30-387, Poland
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY 40202, USA
| | - Maria Solà
- Department of Structural Biology, Molecular Biology Institute of Barcelona, CSIC, Barcelona Science Park, Barcelona E-08028, Spain
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Lau RK, Enustun E, Gu Y, Nguyen JV, Corbett KD. A conserved signaling pathway activates bacterial CBASS immune signaling in response to DNA damage. EMBO J 2022; 41:e111540. [PMID: 36156805 PMCID: PMC9670203 DOI: 10.15252/embj.2022111540] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 01/13/2023] Open
Abstract
To protect themselves from the constant threat of bacteriophage (phage) infection, bacteria have evolved diverse immune systems including restriction-modification, CRISPR-Cas, and many others. Here, we describe the discovery of a two-protein transcriptional regulator module associated with hundreds of CBASS immune systems and demonstrate that this module drives the expression of its associated CBASS system in response to DNA damage. We show that the helix-turn-helix transcriptional repressor CapH binds the promoter region of its associated CBASS system to repress transcription until it is cleaved by the metallopeptidase CapP. CapP is activated in vitro by single-stranded DNA, and in cells by DNA-damaging drugs. Together, CapH and CapP drive increased expression of their associated CBASS system in response to DNA damage. We identify CapH- and CapP-related proteins associated with diverse known and putative bacterial immune systems including DISARM and Pycsar antiphage operons. Overall, our data highlight a mechanism by which bacterial immune systems can sense and respond to a universal signal of cell stress, potentially enabling multiple immune systems to mount a coordinated defensive response against an invading pathogen.
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Affiliation(s)
- Rebecca K Lau
- Department of Cellular and Molecular MedicineUniversity of California, San DiegoLa JollaCAUSA
| | - Eray Enustun
- Department of Molecular Biology, School of Biological SciencesUniversity of California, San DiegoLa JollaCAUSA
| | - Yajie Gu
- Department of Cellular and Molecular MedicineUniversity of California, San DiegoLa JollaCAUSA
| | - Justin V Nguyen
- Department of Molecular Biology, School of Biological SciencesUniversity of California, San DiegoLa JollaCAUSA
| | - Kevin D Corbett
- Department of Cellular and Molecular MedicineUniversity of California, San DiegoLa JollaCAUSA
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15
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Gozzi K, Salinas R, Nguyen VD, Laub MT, Schumacher MA. ssDNA is an allosteric regulator of the C. crescentus SOS-independent DNA damage response transcription activator, DriD. Genes Dev 2022; 36:618-633. [PMID: 35618312 PMCID: PMC9186387 DOI: 10.1101/gad.349541.122] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/12/2022] [Indexed: 12/18/2022]
Abstract
DNA damage repair systems are critical for genomic integrity. However, they must be coordinated with DNA replication and cell division to ensure accurate genomic transmission. In most bacteria, this coordination is mediated by the SOS response through LexA, which triggers a halt in cell division until repair is completed. Recently, an SOS-independent damage response system was revealed in Caulobacter crescentus. This pathway is controlled by the transcription activator, DriD, but how DriD senses and signals DNA damage is unknown. To address this question, we performed biochemical, cellular, and structural studies. We show that DriD binds a specific promoter DNA site via its N-terminal HTH domain to activate transcription of genes, including the cell division inhibitor didA A structure of the C-terminal portion of DriD revealed a WYL motif domain linked to a WCX dimerization domain. Strikingly, we found that DriD binds ssDNA between the WYL and WCX domains. Comparison of apo and ssDNA-bound DriD structures reveals that ssDNA binding orders and orients the DriD domains, indicating a mechanism for ssDNA-mediated operator DNA binding activation. Biochemical and in vivo studies support the structural model. Our data thus reveal the molecular mechanism underpinning an SOS-independent DNA damage repair pathway.
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Affiliation(s)
- Kevin Gozzi
- Department of Biology, Massachusetts Institute of Technology. Cambridge, Massachusetts 02139, USA
| | - Raul Salinas
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Viet D Nguyen
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Michael T Laub
- Department of Biology, Massachusetts Institute of Technology. Cambridge, Massachusetts 02139, USA
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Maria A Schumacher
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA
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16
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Beck IN, Picton DM, Blower TR. Crystal structure of the BREX phage defence protein BrxA. Curr Res Struct Biol 2022; 4:211-219. [PMID: 35783086 PMCID: PMC9240713 DOI: 10.1016/j.crstbi.2022.06.001] [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: 04/19/2022] [Revised: 05/13/2022] [Accepted: 06/01/2022] [Indexed: 11/24/2022] Open
Abstract
Bacteria are constantly challenged by bacteriophage (phage) infection and have developed multitudinous and varied resistance mechanisms. Bacteriophage Exclusion (BREX) systems protect from phage infection by generating methylation patterns at non-palindromic 6 bp sites in host bacterial DNA, to distinguish and block replication of non-self DNA. Type 1 BREX systems are comprised of six conserved core genes. Here, we present the first reported structure of a BREX core protein, BrxA from the phage defence island of Escherichia fergusonii ATCC 35469 plasmid pEFER, solved to 2.09 Å. BrxA is a monomeric protein in solution, with an all α-helical globular fold. Conservation of surface charges and structural homology modelling against known phage defence systems highlighted that BrxA contains two helix-turn-helix motifs, juxtaposed by 180°, positioned to bind opposite sides of a DNA major groove. BrxA was subsequently shown to bind dsDNA. This new understanding of BrxA structure, and first indication of BrxA biological activity, suggests a conserved mode of DNA-recognition has become widespread and implemented by diverse phage defence systems. The crystal structure of BrxA from multi-drug resistant plasmid pEFER of Escherichia fergusonii has been solved to 2.09 Å. BrxA is the first reported structure for a conserved core protein from the widespread BREX phage defence systems. BrxA contains two HTH motifs, analogous to DNA-binding domains of diverse phage defence systems, and is shown to bind dsDNA.
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