1
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Schmid N, Brandt D, Walasek C, Rolland C, Wittmann J, Fischer D, Müsken M, Kalinowski J, Thormann K. An autonomous plasmid as an inovirus phage satellite. Appl Environ Microbiol 2024; 90:e0024624. [PMID: 38597658 PMCID: PMC11107163 DOI: 10.1128/aem.00246-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 03/20/2024] [Indexed: 04/11/2024] Open
Abstract
Bacterial viruses (phages) are potent agents of lateral gene transfer and thus are important drivers of evolution. A group of mobile genetic elements, referred to as phage satellites, exploits phages to disseminate their own genetic material. Here, we isolated a novel member of the family Inoviridae, Shewanella phage Dolos, along with an autonomously replicating plasmid, pDolos. Dolos causes a chronic infection in its host Shewanella oneidensis by phage production with only minor effects on the host cell proliferation. When present, plasmid pDolos hijacks Dolos functions to be predominantly packaged into phage virions and released into the environment and, thus, acts as a phage satellite. pDolos can disseminate further genetic material encoding, e.g., resistances or fluorophores to host cells sensitive to Dolos infection. Given the rather simple requirements of a plasmid for takeover of an inovirus and the wide distribution of phages of this group, we speculate that similar phage-satellite systems are common among bacteria.IMPORTANCEPhage satellites are mobile genetic elements, which hijack phages to be transferred to other host cells. The vast majority of these phage satellites integrate within the host's chromosome, and they all carry remaining phage genes. Here, we identified a novel phage satellite, pDolos, which uses an inovirus for dissemination. pDolos (i) remains as an autonomously replicating plasmid within its host, (ii) does not carry recognizable phage genes, and (iii) is smaller than any other phage satellites identified so far. Thus, pDolos is the first member of a new class of phage satellites, which resemble natural versions of phagemids.
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Affiliation(s)
- Nicole Schmid
- Institute for Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - David Brandt
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Claudia Walasek
- Institute for Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Clara Rolland
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany
| | - Johannes Wittmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany
| | - Dorian Fischer
- Institute for Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Mathias Müsken
- Central Facility for Microscopy, Helmholtz Centre for Infection Research GmbH, Braunschweig, Germany
| | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, Bielefeld, Germany
| | - Kai Thormann
- Institute for Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Gießen, Germany
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2
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Rakibova Y, Dunham DT, Seed KD, Freddolino PL. Nucleoid-associated proteins shape the global protein occupancy and transcriptional landscape of a clinical isolate of Vibrio cholerae. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.30.573743. [PMID: 38260642 PMCID: PMC10802314 DOI: 10.1101/2023.12.30.573743] [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
Vibrio cholerae, the causative agent of the diarrheal disease cholera, poses an ongoing health threat due to its wide repertoire of horizontally acquired elements (HAEs) and virulence factors. New clinical isolates of the bacterium with improved fitness abilities, often associated with HAEs, frequently emerge. The appropriate control and expression of such genetic elements is critical for the bacteria to thrive in the different environmental niches it occupies. H-NS, the histone-like nucleoid structuring protein, is the best studied xenogeneic silencer of HAEs in gamma-proteobacteria. Although H-NS and other highly abundant nucleoid-associated proteins (NAPs) have been shown to play important roles in regulating HAEs and virulence in model bacteria, we still lack a comprehensive understanding of how different NAPs modulate transcription in V. cholerae. By obtaining genome-wide measurements of protein occupancy and active transcription in a clinical isolate of V. cholerae, harboring recently discovered HAEs encoding for phage defense systems, we show that a lack of H-NS causes a robust increase in the expression of genes found in many HAEs. We further found that TsrA, a protein with partial homology to H-NS, regulates virulence genes primarily through modulation of H-NS activity. We also identified a few sites that are affected by TsrA independently of H-NS, suggesting TsrA may act with diverse regulatory mechanisms. Our results demonstrate how the combinatorial activity of NAPs is employed by a clinical isolate of an important pathogen to regulate recently discovered HAEs. Importance New strains of the bacterial pathogen Vibrio cholerae, bearing novel horizontally acquired elements (HAEs), frequently emerge. HAEs provide beneficial traits to the bacterium, such as antibiotic resistance and defense against invading bacteriophages. Xenogeneic silencers are proteins that help bacteria harness new HAEs and silence those HAEs until they are needed. H-NS is the best-studied xenogeneic silencer; it is one of the nucleoid-associated proteins (NAPs) in gamma-proteobacteria and is responsible for the proper regulation of HAEs within the bacterial transcriptional network. We studied the effects of H-NS and other NAPs on the HAEs of a clinical isolate of V. cholerae. Importantly, we found that H-NS partners with a small and poorly characterized protein, TsrA, to help domesticate new HAEs involved in bacterial survival and in causing disease. Proper understanding of the regulatory state in emerging isolates of V. cholerae will provide improved therapies against new isolates of the pathogen.
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Affiliation(s)
- Yulduz Rakibova
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Drew T. Dunham
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Kimberley D. Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - P. Lydia Freddolino
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
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3
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deCarvalho T, Mascolo E, Caruso SM, López-Pérez J, Weston-Hafer K, Shaffer C, Erill I. Simultaneous entry as an adaptation to virulence in a novel satellite-helper system infecting Streptomyces species. THE ISME JOURNAL 2023; 17:2381-2388. [PMID: 37907733 PMCID: PMC10690885 DOI: 10.1038/s41396-023-01548-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/11/2023] [Accepted: 10/16/2023] [Indexed: 11/02/2023]
Abstract
Satellites are mobile genetic elements that are dependent upon the replication machinery of their helper viruses. Bacteriophages have provided many examples of satellite nucleic acids that utilize their helper morphogenic genes for propagation. Here we describe two novel satellite-helper phage systems, Mulch and Flayer, that infect Streptomyces species. The satellites in these systems encode for encapsidation machinery but have an absence of key replication genes, thus providing the first example of bacteriophage satellite viruses. We also show that codon usage of the satellites matches the tRNA gene content of the helpers. The satellite in one of these systems, Flayer, does not appear to integrate into the host genome, which represents the first example of a virulent satellite phage. The Flayer satellite has a unique tail adaptation that allows it to attach to its helper for simultaneous co-infection. These findings demonstrate an ever-increasing array of satellite strategies for genetic dependence on their helpers in the evolutionary arms race between satellite and helper phages.
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Affiliation(s)
- Tagide deCarvalho
- Keith R. Porter Imaging Facility, College of Natural and Mathematical Sciences, University of Maryland Baltimore County, Baltimore, MD, USA
| | - Elia Mascolo
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD, USA
| | - Steven M Caruso
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD, USA
| | - Júlia López-Pérez
- Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | | | - Christopher Shaffer
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
| | - Ivan Erill
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD, USA.
- Departament d'Enginyeria de la Informació i de les Comunicacions, Universitat Autònoma de Barcelona, Bellaterra, Spain.
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4
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Barth ZK, Dunham DT, Seed KD. Nuclease genes occupy boundaries of genetic exchange between bacteriophages. NAR Genom Bioinform 2023; 5:lqad076. [PMID: 37636022 PMCID: PMC10448857 DOI: 10.1093/nargab/lqad076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/13/2023] [Accepted: 08/16/2023] [Indexed: 08/29/2023] Open
Abstract
Homing endonuclease genes (HEGs) are ubiquitous selfish elements that generate targeted double-stranded DNA breaks, facilitating the recombination of the HEG DNA sequence into the break site and contributing to the evolutionary dynamics of HEG-encoding genomes. Bacteriophages (phages) are well-documented to carry HEGs, with the paramount characterization of HEGs being focused on those encoded by coliphage T4. Recently, it has been observed that the highly sampled vibriophage, ICP1, is similarly enriched with HEGs distinct from T4's. Here, we examined the HEGs encoded by ICP1 and diverse phages, proposing HEG-driven mechanisms that contribute to phage evolution. Relative to ICP1 and T4, we found a variable distribution of HEGs across phages, with HEGs frequently encoded proximal to or within essential genes. We identified large regions (> 10kb) of high nucleotide identity flanked by HEGs, deemed HEG islands, which we hypothesize to be mobilized by the activity of flanking HEGs. Finally, we found examples of domain swapping between phage-encoded HEGs and genes encoded by other phages and phage satellites. We anticipate that HEGs have a larger impact on the evolutionary trajectory of phages than previously appreciated and that future work investigating the role of HEGs in phage evolution will continue to highlight these observations.
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Affiliation(s)
- Zachary K Barth
- Department of Plant and Microbial Biology, University of California, Berkeley. 271 Koshland Hall, Berkeley, CA 94720, USA
| | - Drew T Dunham
- Department of Plant and Microbial Biology, University of California, Berkeley. 271 Koshland Hall, Berkeley, CA 94720, USA
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley. 271 Koshland Hall, Berkeley, CA 94720, USA
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5
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Barth ZK, Dunham DT, Seed KD. Nuclease genes occupy boundaries of genetic exchange between bacteriophages. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.23.533998. [PMID: 36993569 PMCID: PMC10055350 DOI: 10.1101/2023.03.23.533998] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Homing endonuclease genes (HEGs) are ubiquitous selfish elements that generate targeted double-stranded DNA breaks, facilitating the recombination of the HEG DNA sequence into the break site and contributing to the evolutionary dynamics of HEG-encoding genomes. Bacteriophages (phages) are well-documented to carry HEGs, with the paramount characterization of HEGs being focused on those encoded by coliphage T4. Recently, it has been observed that the highly sampled vibriophage, ICP1, is similarly enriched with HEGs distinct from T4’s. Here, we examined the HEGs encoded by ICP1 and diverse phages, proposing HEG-driven mechanisms that contribute to phage evolution. Relative to ICP1 and T4, we found a variable distribution of HEGs across phages, with HEGs frequently encoded proximal to or within essential genes. We identified large regions (> 10kb) of high nucleotide identity flanked by HEGs, deemed HEG islands, which we hypothesize to be mobilized by the activity of flanking HEGs. Finally, we found examples of domain swapping between phage-encoded HEGs and genes encoded by other phages and phage satellites. We anticipate that HEGs have a larger impact on the evolutionary trajectory of phages than previously appreciated and that future work investigating the role of HEGs in phage evolution will continue to highlight these observations.
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Affiliation(s)
- Zachary K Barth
- Department of Plant and Microbial Biology, University of California, Berkeley. 271 Koshland Hall, Berkeley, CA 94720, USA
| | - Drew T Dunham
- Department of Plant and Microbial Biology, University of California, Berkeley. 271 Koshland Hall, Berkeley, CA 94720, USA
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley. 271 Koshland Hall, Berkeley, CA 94720, USA
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6
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Marine viral particles reveal an expansive repertoire of phage-parasitizing mobile elements. Proc Natl Acad Sci U S A 2022; 119:e2212722119. [PMID: 36256808 PMCID: PMC9618062 DOI: 10.1073/pnas.2212722119] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Phage satellites are mobile genetic elements that parasitize viruses, exerting profound biological and ecological impacts. Phage satellites are known to infect several gram-positive genera and a few gram-negative bacterial species, most associated with the human microbiome. Direct inspection of “wild” virus particles, however, revealed that marine phage satellites are widely distributed and abundant in the global oceans. Their genetic diversity, gene repertoires, and host ranges appear much greater than has been previously reported. Genetic analyses now provide clues about the parasitic life cycles, helper bacteriophage interactions, and reproductive strategies of these newly recognized marine phage satellites. Their properties, diversity, and environmental distributions suggest they may exert substantial influence on microbial ecology and evolution in the sea. Phage satellites are mobile genetic elements that propagate by parasitizing bacteriophage replication. We report here the discovery of abundant and diverse phage satellites that were packaged as concatemeric repeats within naturally occurring bacteriophage particles in seawater. These same phage-parasitizing mobile elements were found integrated in the genomes of dominant co-occurring bacterioplankton species. Like known phage satellites, many marine phage satellites encoded genes for integration, DNA replication, phage interference, and capsid assembly. Many also contained distinctive gene suites indicative of unique virus hijacking, phage immunity, and mobilization mechanisms. Marine phage satellite sequences were widespread in local and global oceanic virioplankton populations, reflecting their ubiquity, abundance, and temporal persistence in marine planktonic communities worldwide. Their gene content and putative life cycles suggest they may impact host-cell phage immunity and defense, lateral gene transfer, bacteriophage-induced cell mortality and cellular host and virus productivity. Given that marine phage satellites cannot be distinguished from bona fide viral particles via commonly used microscopic techniques, their predicted numbers (∼3.2 × 1026 in the ocean) may influence current estimates of virus densities, production, and virus-induced mortality. In total, the data suggest that marine phage satellites have potential to significantly impact the ecology and evolution of bacteria and their viruses throughout the oceans. We predict that any habitat that harbors bacteriophage will also harbor similar phage satellites, making them a ubiquitous feature of most microbiomes on Earth.
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7
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Nguyen MHT, Netter Z, Angermeyer A, Seed KD. A phage weaponizes a satellite recombinase to subvert viral restriction. Nucleic Acids Res 2022; 50:11138-11153. [PMID: 36259649 DOI: 10.1093/nar/gkac845] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 09/14/2022] [Accepted: 10/10/2022] [Indexed: 11/14/2022] Open
Abstract
Bacteria can acquire mobile genetic elements (MGEs) to combat infection by viruses (phages). Satellite viruses, including the PLEs (phage-inducible chromosomal island-like elements) in epidemic Vibrio cholerae, are MGEs that restrict phage replication to the benefit of their host bacterium. PLEs parasitize the lytic phage ICP1, unleashing multiple mechanisms to restrict phage replication and promote their own spread. In the arms race against PLE, ICP1 uses nucleases, including CRISPR-Cas, to destroy PLE's genome during infection. However, through an unknown CRISPR-independent mechanism, specific ICP1 isolates subvert restriction by PLE. Here, we discover ICP1-encoded Adi that counteracts PLE by exploiting the PLE's large serine recombinase (LSR), which normally mobilizes PLE in response to ICP1 infection. Unlike previously characterized ICP1-encoded anti-PLE mechanisms, Adi is not a nuclease itself but instead appears to modulate the activity of the LSR to promote destructive nuclease activity at the LSR's specific attachment site, attP. The PLE LSR, its catalytic activity, and attP are additionally sufficient to sensitize a PLE encoding a resistant variant of the recombination module to Adi activity. This work highlights a unique type of adaptation arising from inter-genome conflicts, in which the intended activity of a protein can be weaponized to overcome the antagonizing genome.
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Affiliation(s)
- Maria H T Nguyen
- Department of Plant and Microbial Biology, University of California, Berkeley, 271 Koshland Hall, Berkeley, CA 94720, USA
| | - Zoe Netter
- Department of Plant and Microbial Biology, University of California, Berkeley, 271 Koshland Hall, Berkeley, CA 94720, USA
| | - Angus Angermeyer
- Department of Plant and Microbial Biology, University of California, Berkeley, 271 Koshland Hall, Berkeley, CA 94720, USA
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, 271 Koshland Hall, Berkeley, CA 94720, USA
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8
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Haudiquet M, de Sousa JM, Touchon M, Rocha EPC. Selfish, promiscuous and sometimes useful: how mobile genetic elements drive horizontal gene transfer in microbial populations. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210234. [PMID: 35989606 PMCID: PMC9393566 DOI: 10.1098/rstb.2021.0234] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Horizontal gene transfer (HGT) drives microbial adaptation but is often under the control of mobile genetic elements (MGEs) whose interests are not necessarily aligned with those of their hosts. In general, transfer is costly to the donor cell while potentially beneficial to the recipients. The diversity and plasticity of cell–MGEs interactions, and those among MGEs, result in complex evolutionary processes where the source, or even the existence of selection for maintaining a function in the genome, is often unclear. For example, MGE-driven HGT depends on cell envelope structures and defense systems, but many of these are transferred by MGEs themselves. MGEs can spur periods of intense gene transfer by increasing their own rates of horizontal transmission upon communicating, eavesdropping, or sensing the environment and the host physiology. This may result in high-frequency transfer of host genes unrelated to the MGE. Here, we review how MGEs drive HGT and how their transfer mechanisms, selective pressures and genomic traits affect gene flow, and therefore adaptation, in microbial populations. The encoding of many adaptive niche-defining microbial traits in MGEs means that intragenomic conflicts and alliances between cells and their MGEs are key to microbial functional diversification. This article is part of a discussion meeting issue ‘Genomic population structures of microbial pathogens’.
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Affiliation(s)
- Matthieu Haudiquet
- Institut Pasteur, Université de Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris 75015, France
| | - Jorge Moura de Sousa
- Institut Pasteur, Université de Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris 75015, France
| | - Marie Touchon
- Institut Pasteur, Université de Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris 75015, France
| | - Eduardo P C Rocha
- Institut Pasteur, Université de Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris 75015, France
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9
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Development of a Monoclonal Antibody to a Vibriophage as a Proxy for Vibrio cholerae Detection. Infect Immun 2022; 90:e0016122. [PMID: 35862704 PMCID: PMC9387236 DOI: 10.1128/iai.00161-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Cholera is an acute watery, diarrheal disease that causes high rates of morbidity and mortality without treatment. Early detection of the etiologic agent of toxigenic Vibrio cholerae is important to mobilize treatment and mitigate outbreaks. Monoclonal antibody (mAb) based rapid diagnostic tests (RDTs) enable early detection in settings without laboratory capacity. However, the odds of an RDT testing positive are reduced by nearly 90% when the common virulent bacteriophage ICP1 is present. We hypothesize that adding a mAb for the common, and specific, virulent bacteriophage ICP1 as a proxy for V. cholerae to an RDT will increase diagnostic sensitivity when virulent ICP1 phage is present. In this study, we used an in-silico approach to identify immunogenic ICP1 protein targets that were conserved across disparate time periods and locations. Specificity of targets to cholera patients with known ICP1 was determined, and specific targets were used to produce mAbs in a murine model. Candidate mAbs to the head protein demonstrated specificity to ICP1 by Enzyme linked immunosorbent assay (ELISA) and an ICP1 phage neutralization assay. The limit of detection of the final mAb candidate for ICP1 phage particles spiked into cholera stool matrix was 8 × 105 PFU by Western blotting analysis. This mAb will be incorporated into a RDT prototype for evaluation in a future diagnostic study to test the guiding hypothesis behind this study.
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10
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LeGault KN, Barth ZK, DePaola P, Seed KD. A phage parasite deploys a nicking nuclease effector to inhibit viral host replication. Nucleic Acids Res 2022; 50:8401-8417. [PMID: 35066583 PMCID: PMC9410903 DOI: 10.1093/nar/gkac002] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 12/17/2021] [Accepted: 01/12/2022] [Indexed: 12/11/2022] Open
Abstract
PLEs (phage-inducible chromosomal island-like elements) are phage parasites integrated into the chromosome of epidemic Vibrio cholerae. In response to infection by its viral host ICP1, PLE excises, replicates and hijacks ICP1 structural components for transduction. Through an unknown mechanism, PLE prevents ICP1 from transitioning to rolling circle replication (RCR), a prerequisite for efficient packaging of the viral genome. Here, we characterize a PLE-encoded nuclease, NixI, that blocks phage development likely by nicking ICP1’s genome as it transitions to RCR. NixI-dependent cleavage sites appear in ICP1’s genome during infection of PLE(+) V. cholerae. Purified NixI demonstrates in vitro nuclease activity specifically for sites in ICP1’s genome and we identify a motif that is necessary for NixI-mediated cleavage. Importantly, NixI is sufficient to limit ICP1 genome replication and eliminate progeny production, representing the most inhibitory PLE-encoded mechanism revealed to date. We identify distant NixI homologs in an expanded family of putative phage parasites in vibrios that lack nucleotide homology to PLEs but nonetheless share genomic synteny with PLEs. More generally, our results reveal a previously unknown mechanism deployed by phage parasites to limit packaging of their viral hosts’ genome and highlight the prominent role of nuclease effectors as weapons in the arms race between antagonizing genomes.
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Affiliation(s)
- Kristen N LeGault
- Department of Plant and Microbial Biology, University of California, Berkeley, 271 Koshland Hall, Berkeley, CA 94720, USA
| | - Zachary K Barth
- Department of Plant and Microbial Biology, University of California, Berkeley, 271 Koshland Hall, Berkeley, CA 94720, USA
| | - Peter DePaola
- Department of Plant and Microbial Biology, University of California, Berkeley, 271 Koshland Hall, Berkeley, CA 94720, USA
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, 271 Koshland Hall, Berkeley, CA 94720, USA.,Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
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11
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Depelteau JS, Renault L, Althof N, Cassidy CK, Mendonça LM, Jensen GJ, Resch GP, Briegel A. UVC inactivation of pathogenic samples suitable for cryo-EM analysis. Commun Biol 2022; 5:29. [PMID: 35017666 PMCID: PMC8752862 DOI: 10.1038/s42003-021-02962-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 12/07/2021] [Indexed: 12/22/2022] Open
Abstract
Cryo-electron microscopy has become an essential tool to understand structure and function of biological samples. Especially for pathogens, such as disease-causing bacteria and viruses, insights gained by cryo-EM can aid in developing cures. However, due to the biosafety restrictions of pathogens, samples are often treated by chemical fixation to render the pathogen inert, affecting the ultrastructure of the sample. Alternatively, researchers use in vitro or ex vivo models, which are non-pathogenic but lack the complexity of the pathogen of interest. Here we show that ultraviolet-C (UVC) radiation applied at cryogenic temperatures can be used to eliminate or dramatically reduce the infectivity of Vibrio cholerae and the bacterial virus, the ICP1 bacteriophage. We show no discernable structural impact of this treatment of either sample using two cryo-EM methods: cryo-electron tomography followed by sub-tomogram averaging, and single particle analysis (SPA). Additionally, we applied the UVC irradiation to the protein apoferritin (ApoF), which is a widely used test sample for high-resolution SPA studies. The UVC-treated ApoF sample resulted in a 2.1 Å structure indistinguishable from an untreated published map. This research demonstrates that UVC treatment is an effective and inexpensive addition to the cryo-EM sample preparation toolbox. Depelteau et al. present a new method to inactivate cryo-EM samples from pathogenic organisms before imaging using ultraviolet-C radiation in cryogenic conditions. This method allows for the inexpensive preparation of cryo-EM samples with no discernable structural impact of the treatment.
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Affiliation(s)
- Jamie S Depelteau
- Department of Microbial Sciences, Institute of Biology, Leiden University, Sylviusweg 72, 2333, BE, Leiden, The Netherlands
| | - Ludovic Renault
- Netherlands Centre for Electron Nanoscopy (NeCEN), Leiden University, Leiden, The Netherlands
| | - Nynke Althof
- Department of Microbial Sciences, Institute of Biology, Leiden University, Sylviusweg 72, 2333, BE, Leiden, The Netherlands
| | - C Keith Cassidy
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Luiza M Mendonça
- Biology and Bioengineering Department, California Institute of Technology, Pasadena, CA, USA.,Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Grant J Jensen
- Biology and Bioengineering Department, California Institute of Technology, Pasadena, CA, USA and Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
| | - Guenter P Resch
- Nexperion e.U.-Solutions for Electron Microscopy, Vienna, Austria
| | - Ariane Briegel
- Department of Microbial Sciences, Institute of Biology, Leiden University, Sylviusweg 72, 2333, BE, Leiden, The Netherlands. .,Netherlands Centre for Electron Nanoscopy (NeCEN), Leiden University, Leiden, The Netherlands.
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12
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Ibarra-Chávez R, Hansen MF, Pinilla-Redondo R, Seed KD, Trivedi U. Phage satellites and their emerging applications in biotechnology. FEMS Microbiol Rev 2021; 45:fuab031. [PMID: 34104956 PMCID: PMC8632786 DOI: 10.1093/femsre/fuab031] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 06/07/2021] [Indexed: 12/11/2022] Open
Abstract
The arms race between (bacterio)phages and their hosts is a recognised hot spot for genome evolution. Indeed, phages and their components have historically paved the way for many molecular biology techniques and biotech applications. Further exploration into their complex lifestyles has revealed that phages are often parasitised by distinct types of hyperparasitic mobile genetic elements. These so-called phage satellites exploit phages to ensure their own propagation and horizontal transfer into new bacterial hosts, and their prevalence and peculiar lifestyle has caught the attention of many researchers. Here, we review the parasite-host dynamics of the known phage satellites, their genomic organisation and their hijacking mechanisms. Finally, we discuss how these elements can be repurposed for diverse biotech applications, kindling a new catalogue of exciting tools for microbiology and synthetic biology.
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Affiliation(s)
- Rodrigo Ibarra-Chávez
- Section of Microbiology, Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Mads Frederik Hansen
- Section of Microbiology, Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
| | - Rafael Pinilla-Redondo
- Section of Microbiology, Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Urvish Trivedi
- Section of Microbiology, Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark
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13
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Motor-independent retraction of type IV pili is governed by an inherent property of the pilus filament. Proc Natl Acad Sci U S A 2021; 118:2102780118. [PMID: 34789573 DOI: 10.1073/pnas.2102780118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2021] [Indexed: 12/21/2022] Open
Abstract
Type IV pili (T4P) are dynamic surface appendages that promote virulence, biofilm formation, horizontal gene transfer, and motility in diverse bacterial species. Pilus dynamic activity is best characterized in T4P that use distinct ATPase motors for pilus extension and retraction. Many T4P systems, however, lack a dedicated retraction motor, and the mechanism underlying this motor-independent retraction remains a mystery. Using the Vibrio cholerae competence pilus as a model system, we identify mutations in the major pilin gene that enhance motor-independent retraction. These mutants likely diminish pilin-pilin interactions within the filament to produce less-stable pili. One mutation adds a bulky residue to α1C, a universally conserved feature of T4P. We found that inserting a bulky residue into α1C of the retraction motor-dependent Acinetobacter baylyi competence T4P enhances motor-independent retraction. Conversely, removing bulky residues from α1C of the retraction motor-independent, V. cholerae toxin-coregulated T4P stabilizes the filament and diminishes pilus retraction. Furthermore, alignment of pilins from the broader type IV filament (T4F) family indicated that retraction motor-independent T4P, gram-positive Com pili, and type II secretion systems generally encode larger residues within α1C oriented toward the pilus core compared to retraction motor-dependent T4P. Together, our data demonstrate that motor-independent retraction relies, in part, on the inherent instability of the pilus filament, which may be a conserved feature of diverse T4Fs. This provides evidence for a long-standing yet previously untested model in which pili retract in the absence of a motor by spontaneous depolymerization.
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14
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LeGault KN, Hays SG, Angermeyer A, McKitterick AC, Johura FT, Sultana M, Ahmed T, Alam M, Seed KD. Temporal shifts in antibiotic resistance elements govern phage-pathogen conflicts. Science 2021; 373:373/6554/eabg2166. [PMID: 34326207 PMCID: PMC9064180 DOI: 10.1126/science.abg2166] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 06/06/2021] [Indexed: 12/23/2022]
Abstract
Bacteriophage predation selects for diverse antiphage systems that frequently cluster on mobilizable defense islands in bacterial genomes. However, molecular insight into the reciprocal dynamics of phage-bacterial adaptations in nature is lacking, particularly in clinical contexts where there is need to inform phage therapy efforts and to understand how phages drive pathogen evolution. Using time-shift experiments, we uncovered fluctuations in Vibrio cholerae's resistance to phages in clinical samples. We mapped phage resistance determinants to SXT integrative and conjugative elements (ICEs), which notoriously also confer antibiotic resistance. We found that SXT ICEs, which are widespread in γ-proteobacteria, invariably encode phage defense systems localized to a single hotspot of genetic exchange. We identified mechanisms that allow phage to counter SXT-mediated defense in clinical samples, and document the selection of a novel phage-encoded defense inhibitor. Phage infection stimulates high-frequency SXT ICE conjugation, leading to the concurrent dissemination of phage and antibiotic resistances.
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Affiliation(s)
- Kristen N LeGault
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Stephanie G Hays
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Angus Angermeyer
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Amelia C McKitterick
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Fatema-Tuz Johura
- icddr,b, formerly International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Marzia Sultana
- icddr,b, formerly International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Tahmeed Ahmed
- icddr,b, formerly International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Munirul Alam
- icddr,b, formerly International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA.
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
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15
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Boyd CM, Angermeyer A, Hays SG, Barth ZK, Patel KM, Seed KD. Bacteriophage ICP1: A Persistent Predator of Vibrio cholerae. Annu Rev Virol 2021; 8:285-304. [PMID: 34314595 PMCID: PMC9040626 DOI: 10.1146/annurev-virology-091919-072020] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bacteriophages or phages—viruses of bacteria—are abundant and considered to be highly diverse. Interestingly, a particular group of lytic Vibrio cholerae–specific phages (vibriophages) of the International Centre for Diarrheal Disease Research, Bangladesh cholera phage 1 (ICP1) lineage show high levels of genome conservation over large spans of time and geography, despite a constant coevolutionary arms race with their host. From a collection of 67 sequenced ICP1 isolates, mostly from clinical samples, we find these phages have mosaic genomes consisting of large, conserved modules disrupted by variable sequences that likely evolve mostly through mobile endonuclease-mediated recombination during coinfection. Several variable regions have been associated with adaptations against antiphage elements in V. cholerae; notably, this includes ICP1’s CRISPR-Cas system. The ongoing association of ICP1 and V. cholerae in cholera-endemic regions makes this system a rich source for discovery of novel defense and counterdefense strategies in bacteria-phage conflicts in nature.
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Affiliation(s)
- Caroline M Boyd
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Angus Angermeyer
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Stephanie G Hays
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Zachary K Barth
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Kishen M Patel
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA; .,Chan Zuckerberg Biohub, San Francisco, California 94158, USA
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16
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Isaev AB, Musharova OS, Severinov KV. Microbial Arsenal of Antiviral Defenses. Part II. BIOCHEMISTRY (MOSCOW) 2021; 86:449-470. [PMID: 33941066 DOI: 10.1134/s0006297921040064] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Bacteriophages or phages are viruses that infect bacterial cells (for the scope of this review we will also consider viruses that infect Archaea). The constant threat of phage infection is a major force that shapes evolution of microbial genomes. To withstand infection, bacteria had evolved numerous strategies to avoid recognition by phages or to directly interfere with phage propagation inside the cell. Classical molecular biology and genetic engineering had been deeply intertwined with the study of phages and host defenses. Nowadays, owing to the rise of phage therapy, broad application of CRISPR-Cas technologies, and development of bioinformatics approaches that facilitate discovery of new systems, phage biology experiences a revival. This review describes variety of strategies employed by microbes to counter phage infection. In the first part defense associated with cell surface, roles of small molecules, and innate immunity systems relying on DNA modification were discussed. The second part focuses on adaptive immunity systems, abortive infection mechanisms, defenses associated with mobile genetic elements, and novel systems discovered in recent years through metagenomic mining.
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Affiliation(s)
- Artem B Isaev
- Skolkovo Institute of Science and Technology, Skolkovo, Moscow, 143028, Russia.
| | - Olga S Musharova
- Skolkovo Institute of Science and Technology, Skolkovo, Moscow, 143028, Russia. .,Institute of Molecular Genetics, Moscow, 119334, Russia
| | - Konstantin V Severinov
- Skolkovo Institute of Science and Technology, Skolkovo, Moscow, 143028, Russia. .,Waksman Institute of Microbiology, Piscataway, NJ 08854, USA
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17
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Barth ZK, Nguyen MH, Seed KD. A chimeric nuclease substitutes a phage CRISPR-Cas system to provide sequence-specific immunity against subviral parasites. eLife 2021; 10:68339. [PMID: 34232860 PMCID: PMC8263062 DOI: 10.7554/elife.68339] [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: 03/12/2021] [Accepted: 06/27/2021] [Indexed: 02/06/2023] Open
Abstract
Mobile genetic elements, elements that can move horizontally between genomes, have profound effects on their host's fitness. The phage-inducible chromosomal island-like element (PLE) is a mobile element that integrates into the chromosome of Vibrio cholerae and parasitizes the bacteriophage ICP1 to move between cells. This parasitism by PLE is such that it abolishes the production of ICP1 progeny and provides a defensive boon to the host cell population. In response to the severe parasitism imposed by PLE, ICP1 has acquired an adaptive CRISPR-Cas system that targets the PLE genome during infection. However, ICP1 isolates that naturally lack CRISPR-Cas are still able to overcome certain PLE variants, and the mechanism of this immunity against PLE has thus far remained unknown. Here, we show that ICP1 isolates that lack CRISPR-Cas encode an endonuclease in the same locus, and that the endonuclease provides ICP1 with immunity to a subset of PLEs. Further analysis shows that this endonuclease is of chimeric origin, incorporating a DNA-binding domain that is highly similar to some PLE replication origin-binding proteins. This similarity allows the endonuclease to bind and cleave PLE origins of replication. The endonuclease appears to exert considerable selective pressure on PLEs and may drive PLE replication module swapping and origin restructuring as mechanisms of escape. This work demonstrates that new genome defense systems can arise through domain shuffling and provides a greater understanding of the evolutionary forces driving genome modularity and temporal succession in mobile elements.
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Affiliation(s)
- Zachary K Barth
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, United States
| | - Maria Ht Nguyen
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, United States
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, United States.,Chan Zuckerberg Biohub, San Francisco, United States
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18
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Netter Z, Boyd CM, Silvas TV, Seed KD. A phage satellite tunes inducing phage gene expression using a domesticated endonuclease to balance inhibition and virion hijacking. Nucleic Acids Res 2021; 49:4386-4401. [PMID: 33823541 PMCID: PMC8096241 DOI: 10.1093/nar/gkab207] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 02/25/2021] [Accepted: 03/16/2021] [Indexed: 12/20/2022] Open
Abstract
Bacteria persist under constant threat of predation by bacterial viruses (phages). Bacteria-phage conflicts result in evolutionary arms races often driven by mobile genetic elements (MGEs). One such MGE, a phage satellite in Vibrio cholerae called PLE, provides specific and robust defense against a pervasive lytic phage, ICP1. The interplay between PLE and ICP1 has revealed strategies for molecular parasitism allowing PLE to hijack ICP1 processes in order to mobilize. Here, we describe the mechanism of PLE-mediated transcriptional manipulation of ICP1 structural gene transcription. PLE encodes a novel DNA binding protein, CapR, that represses ICP1’s capsid morphogenesis operon. Although CapR is sufficient for the degree of capsid repression achieved by PLE, its activity does not hinder the ICP1 lifecycle. We explore the consequences of repression of this operon, demonstrating that more stringent repression achieved through CRISPRi restricts both ICP1 and PLE. We also discover that PLE transduces in modified ICP1-like particles. Examination of CapR homologs led to the identification of a suite of ICP1-encoded homing endonucleases, providing a putative origin for the satellite-encoded repressor. This work unveils a facet of the delicate balance of satellite-mediated inhibition aimed at blocking phage production while successfully mobilizing in a phage-derived particle.
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Affiliation(s)
- Zoe Netter
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Caroline M Boyd
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Tania V Silvas
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA.,Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
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19
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Szabó M, Murányi G, Kiss J. IncC helper dependent plasmid-like replication of Salmonella Genomic Island 1. Nucleic Acids Res 2021; 49:832-846. [PMID: 33406256 PMCID: PMC7826253 DOI: 10.1093/nar/gkaa1257] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/24/2020] [Accepted: 12/17/2020] [Indexed: 12/16/2022] Open
Abstract
The Salmonella genomic island 1 (SGI1) and its variants are mobilized by IncA and IncC conjugative plasmids. SGI1-family elements and their helper plasmids are effective transporters of multidrug resistance determinants. SGI1 exploits the transfer apparatus of the helper plasmid and hijacks its activator complex, AcaCD, to trigger the expression of several SGI1 genes. In this way, SGI1 times its excision from the chromosome to the helper entry and expresses mating pore components that enhance SGI1 transfer. The SGI1-encoded T4SS components and the FlhDC-family activator proved to be interchangeable with their IncC-encoded homologs, indicating multiple interactions between SGI1 and its helpers. As a new aspect of this crosstalk, we report here the helper-induced replication of SGI1, which requires both activators, AcaCD and FlhDCSGI1, and significantly increases the stability of SGI1 when coexists with the helper plasmid. We have identified the oriVSGI1 and shown that S004-repA operon encodes for a translationally coupled leader protein and an IncN2/N3-related RepA that are expressed under the control of the AcaCD-responsive promoter PS004. This replicon transiently maintains SGI1 as a 4–8-copy plasmid, not only stabilizing the island but also contributing to the fast displacement of the helper plasmid.
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Affiliation(s)
- Mónika Szabó
- Agricultural Biotechnology Institute, National Agricultural Research and Innovation Centre, Gödöllő H2100, Hungary
| | - Gábor Murányi
- Agricultural Biotechnology Institute, National Agricultural Research and Innovation Centre, Gödöllő H2100, Hungary
| | - János Kiss
- Agricultural Biotechnology Institute, National Agricultural Research and Innovation Centre, Gödöllő H2100, Hungary
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