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Geyman LJ, Tanner MP, Rosario-Meléndez N, Peters JM, Mandel MJ, van Kessel JC. Mobile-CRISPRi as a powerful tool for modulating Vibrio gene expression. Appl Environ Microbiol 2024; 90:e0006524. [PMID: 38775491 PMCID: PMC11218623 DOI: 10.1128/aem.00065-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 04/28/2024] [Indexed: 05/25/2024] Open
Abstract
CRISPRi (Clustered Regularly Interspaced Palindromic Repeats interference) is a gene knockdown method that uses a deactivated Cas9 protein (dCas9) that binds a specific gene target locus dictated by an encoded guide RNA (sgRNA) to block transcription. Mobile-CRISPRi is a suite of modular vectors that enable CRISPRi knockdowns in diverse bacteria by integrating IPTG-inducible dcas9 and sgRNA genes into the genome using Tn7 transposition. Here, we show that the Mobile-CRISPRi system functions robustly and specifically in multiple Vibrio species: Vibrio cholerae, Vibrio fischeri, Vibrio vulnificus, Vibrio parahaemolyticus, and Vibrio campbellii. We demonstrate efficacy by targeting both essential and non-essential genes that function to produce defined, measurable phenotypes: bioluminescence, quorum sensing, cell division, and growth arrest. We anticipate that Mobile-CRISPRi will be used in Vibrio species to systematically probe gene function and essentiality in various behaviors and native environments.IMPORTANCEThe genetic manipulation of bacterial genomes is an invaluable tool in experimental microbiology. The development of CRISPRi (Clustered Regularly Interspaced Palindromic Repeats interference) tools has revolutionized genetics in many organisms, including bacteria. Here, we optimized the use of Mobile-CRISPRi in five Vibrio species, each of which has significant impacts on marine environments and organisms that include squid, shrimp, shellfish, finfish, corals, and multiple of which pose direct threats to human health. The Mobile-CRISPRi technology is easily adaptable, moveable from strain to strain, and enables researchers to selectively turn off gene expression. Our experiments demonstrate Mobile-CRISPRi is effective and robust at repressing gene expression of both essential and non-essential genes in Vibrio species.
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Affiliation(s)
- Logan J. Geyman
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Madeline P. Tanner
- Department of Microbiology, School of Medicine, University of Washington, Seattle, Washington, USA
| | - Natalia Rosario-Meléndez
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jason M. Peters
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Mark J. Mandel
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
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2
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Beamud B, Benz F, Bikard D. Going viral: The role of mobile genetic elements in bacterial immunity. Cell Host Microbe 2024; 32:804-819. [PMID: 38870898 DOI: 10.1016/j.chom.2024.05.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 05/17/2024] [Accepted: 05/20/2024] [Indexed: 06/15/2024]
Abstract
Bacteriophages and other mobile genetic elements (MGEs) pose a significant threat to bacteria, subjecting them to constant attacks. In response, bacteria have evolved a sophisticated immune system that employs diverse defensive strategies and mechanisms. Remarkably, a growing body of evidence suggests that most of these defenses are encoded by MGEs themselves. This realization challenges our traditional understanding of bacterial immunity and raises intriguing questions about the evolutionary forces at play. Our review provides a comprehensive overview of the latest findings on the main families of MGEs and the defense systems they encode. We also highlight how a vast diversity of defense systems remains to be discovered and their mechanism of mobility understood. Altogether, the composition and distribution of defense systems in bacterial genomes only makes sense in the light of the ecological and evolutionary interactions of a complex network of MGEs.
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Affiliation(s)
- Beatriz Beamud
- Institut Pasteur, Université de Paris, Synthetic Biology, 75015 Paris, France.
| | - Fabienne Benz
- Institut Pasteur, Université de Paris, Synthetic Biology, 75015 Paris, France; Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, 75015 Paris, France
| | - David Bikard
- Institut Pasteur, Université de Paris, Synthetic Biology, 75015 Paris, France.
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3
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Gluck-Thaler E, Vogan A. Systematic identification of cargo-mobilizing genetic elements reveals new dimensions of eukaryotic diversity. Nucleic Acids Res 2024; 52:5496-5513. [PMID: 38686785 PMCID: PMC11162782 DOI: 10.1093/nar/gkae327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 03/12/2024] [Accepted: 04/15/2024] [Indexed: 05/02/2024] Open
Abstract
Cargo-mobilizing mobile elements (CMEs) are genetic entities that faithfully transpose diverse protein coding sequences. Although common in bacteria, we know little about eukaryotic CMEs because no appropriate tools exist for their annotation. For example, Starships are giant fungal CMEs whose functions are largely unknown because they require time-intensive manual curation. To address this knowledge gap, we developed starfish, a computational workflow for high-throughput eukaryotic CME annotation. We applied starfish to 2 899 genomes of 1 649 fungal species and found that starfish recovers known Starships with 95% combined precision and recall while expanding the number of annotated elements ten-fold. Extant Starship diversity is partitioned into 11 families that differ in their enrichment patterns across fungal classes. Starship cargo changes rapidly such that elements from the same family differ substantially in their functional repertoires, which are predicted to contribute to diverse biological processes such as metabolism. Many elements have convergently evolved to insert into 5S rDNA and AT-rich sequence while others integrate into random locations, revealing both specialist and generalist strategies for persistence. Our work establishes a framework for advancing mobile element biology and provides the means to investigate an emerging dimension of eukaryotic genetic diversity, that of genomes within genomes.
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Affiliation(s)
- Emile Gluck-Thaler
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, Neuchâtel, Neuchâtel 2000, Switzerland
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, USA
- Wisconsin Institute for Discovery, Madison, WI 53706, USA
| | - Aaron A Vogan
- Systematic Biology, Department of Organismal Biology, Uppsala University, Uppsala, 752 36, Sweden
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4
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Correa A, Shehreen S, Machado LC, Thesier J, Cunic L, Petassi M, Chu J, Kapili B, Jia Y, England K, Peters J. Novel mechanisms of diversity generation in Acinetobacter baumannii resistance islands driven by Tn7-like elements. Nucleic Acids Res 2024; 52:3180-3198. [PMID: 38407477 PMCID: PMC11014353 DOI: 10.1093/nar/gkae129] [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: 07/26/2023] [Revised: 01/25/2024] [Accepted: 02/09/2024] [Indexed: 02/27/2024] Open
Abstract
Mobile genetic elements play an important role in the acquisition of antibiotic and biocide resistance, especially through the formation of resistance islands in bacterial chromosomes. We analyzed the contribution of Tn7-like transposons to island formation and diversification in the nosocomial pathogen Acinetobacter baumannii and identified four separate families that recognize different integration sites. One integration site is within the comM gene and coincides with the previously described Tn6022 elements suggested to account for the AbaR resistance island. We established Tn6022 in a heterologous E. coli host and confirmed basic features of transposition into the comM attachment site and the use of a novel transposition protein. By analyzing population features within Tn6022 elements we identified two potential novel transposon-encoded diversification mechanisms with this dynamic genetic island. The activities of these diversification features were confirmed in E. coli. One was a novel natural gain-of-activity allele that could function to broaden transposition targeting. The second was a transposon-encoded hybrid dif-like site that parasitizes the host dimer chromosome resolution system to function with its own tyrosine recombinase. This work establishes a highly active Tn7-like transposon that harnesses novel features allowing the spread and diversification of genetic islands in pathogenic bacteria.
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Affiliation(s)
- Alberto Correa
- Department of Microbiology, Cornell University, Ithaca, NY, USA
| | | | | | - Jordan Thesier
- Department of Microbiology, Cornell University, Ithaca, NY, USA
| | - Lille M Cunic
- Department of Microbiology, Cornell University, Ithaca, NY, USA
| | | | - Joshua Chu
- Department of Microbiology, Cornell University, Ithaca, NY, USA
| | | | - Yu Jia
- College of Life Sciences and Engineering Research Center of Bioreactor and Pharmaceutical Development (Ministry of Education), Jilin Agricultural University, Changchun City, Jilin Province, China
| | - Kevin A England
- Department of Microbiology, Cornell University, Ithaca, NY, USA
| | - Joseph E Peters
- Department of Microbiology, Cornell University, Ithaca, NY, USA
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5
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Hwang Y, Cornman AL, Kellogg EH, Ovchinnikov S, Girguis PR. Genomic language model predicts protein co-regulation and function. Nat Commun 2024; 15:2880. [PMID: 38570504 PMCID: PMC10991518 DOI: 10.1038/s41467-024-46947-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 03/13/2024] [Indexed: 04/05/2024] Open
Abstract
Deciphering the relationship between a gene and its genomic context is fundamental to understanding and engineering biological systems. Machine learning has shown promise in learning latent relationships underlying the sequence-structure-function paradigm from massive protein sequence datasets. However, to date, limited attempts have been made in extending this continuum to include higher order genomic context information. Evolutionary processes dictate the specificity of genomic contexts in which a gene is found across phylogenetic distances, and these emergent genomic patterns can be leveraged to uncover functional relationships between gene products. Here, we train a genomic language model (gLM) on millions of metagenomic scaffolds to learn the latent functional and regulatory relationships between genes. gLM learns contextualized protein embeddings that capture the genomic context as well as the protein sequence itself, and encode biologically meaningful and functionally relevant information (e.g. enzymatic function, taxonomy). Our analysis of the attention patterns demonstrates that gLM is learning co-regulated functional modules (i.e. operons). Our findings illustrate that gLM's unsupervised deep learning of the metagenomic corpus is an effective and promising approach to encode functional semantics and regulatory syntax of genes in their genomic contexts and uncover complex relationships between genes in a genomic region.
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Affiliation(s)
- Yunha Hwang
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.
| | | | - Elizabeth H Kellogg
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Sergey Ovchinnikov
- John Harvard Distinguished Science Fellowship Program, Harvard University, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Peter R Girguis
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA.
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6
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Deep A, Liang Q, Enustun E, Pogliano J, Corbett KD. Architecture and infection-sensing mechanism of the bacterial PARIS defense system. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.02.573835. [PMID: 38260510 PMCID: PMC10802264 DOI: 10.1101/2024.01.02.573835] [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
Bacteria and the viruses that infect them (bacteriophages or phages) are engaged in an evolutionary arms race that has resulted in the development of hundreds of bacterial defense systems and myriad phage-encoded counterdefenses1-5. While the mechanisms of many bacterial defense systems are known1, how these systems avoid toxicity outside infection yet activate quickly upon sensing phage infection is less well understood. Here, we show that the bacterial Phage Anti-Restriction-Induced System (PARIS) operates as a toxin-antitoxin system, in which the antitoxin AriA sequesters and inactivates the toxin AriB until triggered by the T7 phage counterdefense protein Ocr. Using cryoelectron microscopy (cryoEM), we show that AriA is structurally similar to dimeric SMC-family ATPases but assembles into a distinctive homohexameric complex through two distinct oligomerization interfaces. In the absence of infection, the AriA hexamer binds up to three monomers of AriB, maintaining them in an inactive state. Ocr binding to the AriA-AriB complex triggers rearrangement of the AriA hexamer, releasing AriB and allowing it to dimerize and activate. AriB is a toprim/OLD-family nuclease whose activation arrests cell growth and inhibits phage propagation by globally inhibiting protein translation. Collectively, our findings reveal the intricate molecular mechanisms of a bacterial defense system that evolved in response to a phage counterdefense protein, and highlight how an SMC-family ATPase has been adapted as a bacterial infection sensor.
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Affiliation(s)
- Amar Deep
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla CA, USA
| | - Qishan Liang
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla CA, USA
| | - Eray Enustun
- Department of Molecular Biology, University of California San Diego, La Jolla CA, USA
| | - Joe Pogliano
- Department of Molecular Biology, University of California San Diego, La Jolla CA, USA
| | - Kevin D. Corbett
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla CA, USA
- Department of Molecular Biology, University of California San Diego, La Jolla CA, USA
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7
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Schmitz M, Querques I. DNA on the move: mechanisms, functions and applications of transposable elements. FEBS Open Bio 2024; 14:13-22. [PMID: 38041553 PMCID: PMC10761935 DOI: 10.1002/2211-5463.13743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 10/24/2023] [Accepted: 11/30/2023] [Indexed: 12/03/2023] Open
Abstract
Transposons are mobile genetic elements that have invaded all domains of life by moving between and within their host genomes. Due to their mobility (or transposition), transposons facilitate horizontal gene transfer in bacteria and foster the evolution of new molecular functions in prokaryotes and eukaryotes. As transposition can lead to detrimental genomic rearrangements, organisms have evolved a multitude of molecular strategies to control transposons, including genome defense mechanisms provided by CRISPR-Cas systems. Apart from their biological impacts on genomes, DNA transposons have been leveraged as efficient gene insertion vectors in basic research, transgenesis and gene therapy. However, the close to random insertion profile of transposon-based tools limits their programmability and safety. Despite recent advances brought by the development of CRISPR-associated genome editing nucleases, a strategy for efficient insertion of large, multi-kilobase transgenes at user-defined genomic sites is currently challenging. The discovery and experimental characterization of bacterial CRISPR-associated transposons (CASTs) led to the attractive hypothesis that these systems could be repurposed as programmable, site-specific gene integration technologies. Here, we provide a broad overview of the molecular mechanisms underpinning DNA transposition and of its biological and technological impact. The second focus of the article is to describe recent mechanistic and functional analyses of CAST transposition. Finally, current challenges and desired future advances of CAST-based genome engineering applications are briefly discussed.
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Affiliation(s)
| | - Irma Querques
- Department of BiochemistryUniversity of ZurichSwitzerland
- Max Perutz Labs, Vienna Biocenter Campus (VBC)Austria
- Department of Structural and Computational Biology, Center for Molecular BiologyUniversity of ViennaAustria
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8
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Koonin EV, Krupovic M. New faces of prokaryotic mobile genetic elements: guide RNAs link transposition with host defense mechanisms. CURRENT OPINION IN SYSTEMS BIOLOGY 2023; 36:100473. [PMID: 37779558 PMCID: PMC10538440 DOI: 10.1016/j.coisb.2023.100473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Most life forms harbor multiple, diverse mobile genetic elements (MGE) that widely differ in their rates and mechanisms of mobility. Recent findings on two classes of MGE in prokaryotes revealed a novel mechanism, RNA-guided transposition, where a transposon-encoded guide RNA directs the transposase to a unique site in the host genome. Tn7-like transposons, on multiple occasions, recruited CRISPR systems that lost the capacity to cleave target DNA and instead mediate RNA-guided transposition via CRISPR RNA. Conversely, the abundant transposon-associated, RNA-guided nucleases IscB and TnpB that appear to promote proliferation of IS200/IS605 and IS607 transposons were the likely evolutionary ancestors of type II and type V CRISPR systems, respectively. Thus, RNA-guided target recognition is a major biological phenomenon that connects MGE with host defense mechanisms. More RNA-guided defensive and MGE-associated functionalities are likely to be discovered.
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Affiliation(s)
- Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD, USA
| | - Mart Krupovic
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Archaeal Virology Unit, 25 rue du Dr Roux, 75015 Paris
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9
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Yáñez-Cuna FO, Koszul R. Insights in bacterial genome folding. Curr Opin Struct Biol 2023; 82:102679. [PMID: 37604045 DOI: 10.1016/j.sbi.2023.102679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 07/18/2023] [Accepted: 07/19/2023] [Indexed: 08/23/2023]
Abstract
Chromosomes in all domains of life are well-defined structural entities with complex hierarchical organization. The regulation of this hierarchical organization and its functional interplay with gene expression or other chromosome metabolic processes such as repair, replication, or segregation is actively investigated in a variety of species, including prokaryotes. Bacterial chromosomes are typically gene-dense with few non-coding sequences and are organized into the nucleoid, a membrane-less compartment composed of DNA, RNA, and proteins (nucleoid-associated proteins or NAPs). The continuous improvement of imaging and genomic methods has put the organization of these Mb-long molecules at reach, allowing to disambiguate some of their highly dynamic properties and intertwined structural features. Here we review and discuss some of the recent advances in the field of bacterial chromosome organization.
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Affiliation(s)
- Fares Osam Yáñez-Cuna
- Institut Pasteur, CNRS UMR 3525, Université Paris Cité, Unité Régulation Spatiale des Génomes, 75015, Paris, France
| | - Romain Koszul
- Institut Pasteur, CNRS UMR 3525, Université Paris Cité, Unité Régulation Spatiale des Génomes, 75015, Paris, France.
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10
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Georjon H, Bernheim A. The highly diverse antiphage defence systems of bacteria. Nat Rev Microbiol 2023; 21:686-700. [PMID: 37460672 DOI: 10.1038/s41579-023-00934-x] [Citation(s) in RCA: 57] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2023] [Indexed: 09/14/2023]
Abstract
Bacteria and their viruses have coevolved for billions of years. This ancient and still ongoing arms race has led bacteria to develop a vast antiphage arsenal. The development of high-throughput screening methods expanded our knowledge of defence systems from a handful to more than a hundred systems, unveiling many different molecular mechanisms. These findings reveal that bacterial immunity is much more complex than previously thought. In this Review, we explore recently discovered bacterial antiphage defence systems, with a particular focus on their molecular diversity, and discuss the ecological and evolutionary drivers and implications of the existing diversity of antiphage defence mechanisms.
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Affiliation(s)
- Héloïse Georjon
- Molecular Diversity of Microbes Lab, Institut Pasteur, Université Paris Cité, INSERM, Paris, France
| | - Aude Bernheim
- Molecular Diversity of Microbes Lab, Institut Pasteur, Université Paris Cité, INSERM, Paris, France.
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11
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Weisberg AJ, Chang JH. Mobile Genetic Element Flexibility as an Underlying Principle to Bacterial Evolution. Annu Rev Microbiol 2023; 77:603-624. [PMID: 37437216 DOI: 10.1146/annurev-micro-032521-022006] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Mobile genetic elements are key to the evolution of bacteria and traits that affect host and ecosystem health. Here, we use a framework of a hierarchical and modular system that scales from genes to populations to synthesize recent findings on mobile genetic elements (MGEs) of bacteria. Doing so highlights the role that emergent properties of flexibility, robustness, and genetic capacitance of MGEs have on the evolution of bacteria. Some of their traits can be stored, shared, and diversified across different MGEs, taxa of bacteria, and time. Collectively, these properties contribute to maintaining functionality against perturbations while allowing changes to accumulate in order to diversify and give rise to new traits. These properties of MGEs have long challenged our abilities to study them. Implementation of new technologies and strategies allows for MGEs to be analyzed in new and powerful ways.
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Affiliation(s)
- Alexandra J Weisberg
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA;
| | - Jeff H Chang
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA;
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12
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Tisza MJ, Smith DDN, Clark AE, Youn JH, Khil PP, Dekker JP. Roving methyltransferases generate a mosaic epigenetic landscape and influence evolution in Bacteroides fragilis group. Nat Commun 2023; 14:4082. [PMID: 37429841 DOI: 10.1038/s41467-023-39892-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 06/29/2023] [Indexed: 07/12/2023] Open
Abstract
Three types of DNA methyl modifications have been detected in bacterial genomes, and mechanistic studies have demonstrated roles for DNA methylation in physiological functions ranging from phage defense to transcriptional control of virulence and host-pathogen interactions. Despite the ubiquity of methyltransferases and the immense variety of possible methylation patterns, epigenomic diversity remains unexplored for most bacterial species. Members of the Bacteroides fragilis group (BFG) reside in the human gastrointestinal tract as key players in symbiotic communities but also can establish anaerobic infections that are increasingly multi-drug resistant. In this work, we utilize long-read sequencing technologies to perform pangenomic (n = 383) and panepigenomic (n = 268) analysis of clinical BFG isolates cultured from infections seen at the NIH Clinical Center over four decades. Our analysis reveals that single BFG species harbor hundreds of DNA methylation motifs, with most individual motif combinations occurring uniquely in single isolates, implying immense unsampled methylation diversity within BFG epigenomes. Mining of BFG genomes identified more than 6000 methyltransferase genes, approximately 1000 of which were associated with intact prophages. Network analysis revealed substantial gene flow among disparate phage genomes, implying a role for genetic exchange between BFG phages as one of the ultimate sources driving BFG epigenome diversity.
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Affiliation(s)
- Michael J Tisza
- Bacterial Pathogenesis and Antimicrobial Resistance Unit, LCIM, NIAID, NIH, Bethesda, MD, USA
- The Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiol, Baylor College of Medicine, Houston, TX, USA
| | - Derek D N Smith
- Bacterial Pathogenesis and Antimicrobial Resistance Unit, LCIM, NIAID, NIH, Bethesda, MD, USA
- Environment and Climate Change Canada, Ecotoxicology and Wildlife Health Division, Wildlife Toxicology Research Section, Ottawa, ON, Canada
| | - Andrew E Clark
- National Institutes of Health Clinical Center, NIH, Bethesda, MD, USA
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jung-Ho Youn
- National Institutes of Health Clinical Center, NIH, Bethesda, MD, USA
| | - Pavel P Khil
- Bacterial Pathogenesis and Antimicrobial Resistance Unit, LCIM, NIAID, NIH, Bethesda, MD, USA
- National Institutes of Health Clinical Center, NIH, Bethesda, MD, USA
| | - John P Dekker
- Bacterial Pathogenesis and Antimicrobial Resistance Unit, LCIM, NIAID, NIH, Bethesda, MD, USA.
- National Institutes of Health Clinical Center, NIH, Bethesda, MD, USA.
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13
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Mayo-Muñoz D, Pinilla-Redondo R, Birkholz N, Fineran PC. A host of armor: Prokaryotic immune strategies against mobile genetic elements. Cell Rep 2023; 42:112672. [PMID: 37347666 DOI: 10.1016/j.celrep.2023.112672] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 05/22/2023] [Accepted: 06/02/2023] [Indexed: 06/24/2023] Open
Abstract
Prokaryotic adaptation is strongly influenced by the horizontal acquisition of beneficial traits via mobile genetic elements (MGEs), such as viruses/bacteriophages and plasmids. However, MGEs can also impose a fitness cost due to their often parasitic nature and differing evolutionary trajectories. In response, prokaryotes have evolved diverse immune mechanisms against MGEs. Recently, our understanding of the abundance and diversity of prokaryotic immune systems has greatly expanded. These defense systems can degrade the invading genetic material, inhibit genome replication, or trigger abortive infection, leading to population protection. In this review, we highlight these strategies, focusing on the most recent discoveries. The study of prokaryotic defenses not only sheds light on microbial evolution but also uncovers novel enzymatic activities with promising biotechnological applications.
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Affiliation(s)
- David Mayo-Muñoz
- Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Genetics Otago, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
| | - Rafael Pinilla-Redondo
- Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Nils Birkholz
- Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Genetics Otago, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Bioprotection Aotearoa, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand
| | - Peter C Fineran
- Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Genetics Otago, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand; Bioprotection Aotearoa, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
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14
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Boyle TA, Hatoum-Aslan A. Recurring and emerging themes in prokaryotic innate immunity. Curr Opin Microbiol 2023; 73:102324. [PMID: 37163858 PMCID: PMC10360293 DOI: 10.1016/j.mib.2023.102324] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 04/06/2023] [Accepted: 04/07/2023] [Indexed: 05/12/2023]
Abstract
A resurgence of interest in the pathways that bacteria use to protect against their viruses (i.e. phages) has led to the discovery of dozens of new antiphage defenses. Given the sheer abundance and diversity of phages - the ever-evolving targets of immunity - it is not surprising that these newly described defenses are also remarkably diverse. However, as their mechanisms slowly come into focus, some common strategies and themes are also beginning to emerge. This review highlights recurring and emerging themes in the mechanisms of innate immunity in bacteria and archaea, with an emphasis on recently described systems that have undergone more thorough mechanistic characterization.
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Affiliation(s)
- Tori A Boyle
- University of Illinois at Urbana-Champaign, Department of Microbiology, Urbana, IL 61801, USA
| | - Asma Hatoum-Aslan
- University of Illinois at Urbana-Champaign, Department of Microbiology, Urbana, IL 61801, USA.
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15
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Faure G, Saito M, Benler S, Peng I, Wolf YI, Strecker J, Altae-Tran H, Neumann E, Li D, Makarova KS, Macrae RK, Koonin EV, Zhang F. Modularity and diversity of target selectors in Tn7 transposons. Mol Cell 2023:S1097-2765(23)00367-2. [PMID: 37267947 DOI: 10.1016/j.molcel.2023.05.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 01/17/2023] [Accepted: 05/09/2023] [Indexed: 06/04/2023]
Abstract
To spread, transposons must integrate into target sites without disruption of essential genes while avoiding host defense systems. Tn7-like transposons employ multiple mechanisms for target-site selection, including protein-guided targeting and, in CRISPR-associated transposons (CASTs), RNA-guided targeting. Combining phylogenomic and structural analyses, we conducted a broad survey of target selectors, revealing diverse mechanisms used by Tn7 to recognize target sites, including previously uncharacterized target-selector proteins found in newly discovered transposable elements (TEs). We experimentally characterized a CAST I-D system and a Tn6022-like transposon that uses TnsF, which contains an inactivated tyrosine recombinase domain, to target the comM gene. Additionally, we identified a non-Tn7 transposon, Tsy, encoding a homolog of TnsF with an active tyrosine recombinase domain, which we show also inserts into comM. Our findings show that Tn7 transposons employ modular architecture and co-opt target selectors from various sources to optimize target selection and drive transposon spread.
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Affiliation(s)
- Guilhem Faure
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Makoto Saito
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sean Benler
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA
| | - Iris Peng
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA
| | - Jonathan Strecker
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Han Altae-Tran
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Edwin Neumann
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - David Li
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA
| | - Rhiannon K Macrae
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA.
| | - Feng Zhang
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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16
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Hochhauser D, Millman A, Sorek R. The defense island repertoire of the Escherichia coli pan-genome. PLoS Genet 2023; 19:e1010694. [PMID: 37023146 PMCID: PMC10121019 DOI: 10.1371/journal.pgen.1010694] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/21/2023] [Accepted: 03/06/2023] [Indexed: 04/08/2023] Open
Abstract
It has become clear in recent years that anti-phage defense systems cluster non-randomly within bacterial genomes in so-called "defense islands". Despite serving as a valuable tool for the discovery of novel defense systems, the nature and distribution of defense islands themselves remain poorly understood. In this study, we comprehensively mapped the defense system repertoire of >1,300 strains of Escherichia coli, the most widely studied organism for phage-bacteria interactions. We found that defense systems are usually carried on mobile genetic elements including prophages, integrative conjugative elements and transposons, which preferentially integrate at several dozens of dedicated hotspots in the E. coli genome. Each mobile genetic element type has a preferred integration position but can carry a diverse variety of defensive cargo. On average, an E. coli genome has 4.7 hotspots occupied by defense system-containing mobile elements, with some strains possessing up to eight defensively occupied hotspots. Defense systems frequently co-localize with other systems on the same mobile genetic element, in agreement with the observed defense island phenomenon. Our data show that the overwhelming majority of the E. coli pan-immune system is carried on mobile genetic elements, explaining why the immune repertoire varies substantially between different strains of the same species.
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Affiliation(s)
- Dina Hochhauser
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Adi Millman
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Rotem Sorek
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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17
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Hossain M, Aslan B, Hatoum-Aslan A. Tandem mobilization of anti-phage defenses alongside SCC mec cassettes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.17.533233. [PMID: 36993521 PMCID: PMC10055296 DOI: 10.1101/2023.03.17.533233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Bacterial viruses (phages) and the immune systems targeted against them significantly impact bacterial survival, evolution, and the emergence of pathogenic strains. While recent research has made spectacular strides towards discovering and validating new defenses in a few model organisms1-3, the inventory of immune systems in clinically-relevant bacteria remains underexplored, and little is known about the mechanisms by which these systems horizontally spread. Such pathways not only impact the evolutionary trajectory of bacterial pathogens, but also threaten to undermine the effectiveness of phage-based therapeutics. Here, we investigate the battery of defenses in staphylococci, opportunistic pathogens that constitute leading causes of antibiotic-resistant infections. We show that these organisms harbor a variety of anti-phage defenses encoded within/near the infamous SCC (staphylococcal cassette chromosome) mec cassettes, mobile genomic islands that confer methicillin resistance. Importantly, we demonstrate that SCCmec-encoded recombinases mobilize not only SCCmec, but also tandem cassettes enriched with diverse defenses. Further, we show that phage infection potentiates cassette mobilization. Taken together, our findings reveal that beyond spreading antibiotic resistance, SCCmec cassettes play a central role in disseminating anti-phage defenses. This work underscores the urgent need for developing adjunctive treatments that target this pathway to save the burgeoning phage therapeutics from suffering the same fate as conventional antibiotics.
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Affiliation(s)
- Motaher Hossain
- University of Illinois at Urbana-Champaign, Department of Microbiology, Urbana, IL, USA
| | - Barbaros Aslan
- University of Illinois at Urbana-Champaign, Department of Microbiology, Urbana, IL, USA
| | - Asma Hatoum-Aslan
- University of Illinois at Urbana-Champaign, Department of Microbiology, Urbana, IL, USA
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18
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Jiang Y, Zhao L, Li JD, Sun J, Miao R, Shao B, Wu P. The universality of eAREs in animal feces suggesting that eAREs function possibly in horizontal gene transfer. J Adv Vet Anim Res 2023; 10:103-112. [PMID: 37155541 PMCID: PMC10122938 DOI: 10.5455/javar.2023.j658] [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: 01/03/2023] [Revised: 03/02/2023] [Accepted: 03/05/2023] [Indexed: 05/10/2023] Open
Abstract
Objectives This study aimed to pinpoint the universality of extracellular antimicrobial resistance elements (eAREs) and compare the contents of eAREs with those of intracellular AREs (iAREs) in animal feces, thus laying a foundation for the further analysis of the horizontal transfer of antimicrobial resistance genes (ARGs) in the animal guts. Materials and Methods Extracellular DNAs were isolated from the fecal samples of Pavo cristatus (n = 18), Ursus thibetanus (n = 2), two breeds of broilers (n = 21 and 11, respectively), and from the contents of rabbit intestines (n = 5). eAREs were detected by PCR technology. iAREs in P. cristatus and broiler feces were also detected and compared with the corresponding eAREs. In addition, some gene cassettes of class 1 integrons were sequenced and analyzed. Results The results showed that eAREs exist in animal feces and intestinal contents. In this study, different eAREs were detected from animal feces and intestinal contents, and tetA, tetB, sul1, sul2, class 1 integron, and IncFIB presented the highest detection rates. The detection rates of certain eAREs were significantly higher than those of parallel iAREs. The integral cassettes with intact structures were found in eAREs, and the cassettes carried ARGs. Conclusions The presented study here sheds light on the presence of eAREs in animal feces or guts, and eAREs may play an important role in the horizontal gene transfer of ARGs.
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Affiliation(s)
- Yusha Jiang
- College of Life Sciences, Southwest Forestry University, Kunming, China
| | - Lang Zhao
- College of Life Sciences, Southwest Forestry University, Kunming, China
| | - Jia Danyang Li
- College of Life Sciences, Southwest Forestry University, Kunming, China
| | - Jialiang Sun
- College of Life Sciences, Southwest Forestry University, Kunming, China
| | - Rui Miao
- College of Life Sciences, Southwest Forestry University, Kunming, China
| | - Bo Shao
- College of Life Sciences, Southwest Forestry University, Kunming, China
| | - Peifu Wu
- College of Life Sciences, Southwest Forestry University, Kunming, China
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19
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Hsieh SC, Peters JE. Discovery and characterization of novel type I-D CRISPR-guided transposons identified among diverse Tn7-like elements in cyanobacteria. Nucleic Acids Res 2023; 51:765-782. [PMID: 36537206 PMCID: PMC9881144 DOI: 10.1093/nar/gkac1216] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/01/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022] Open
Abstract
CRISPR-Cas defense systems have been naturally coopted for guide RNA-directed transposition by Tn7 family bacterial transposons. We find cyanobacterial genomes are rich in Tn7-like elements, including most of the known guide RNA-directed transposons, the type V-K, I-B1, and I-B2 CRISPR-Cas based systems. We discovered and characterized an example of a type I-D CRISPR-Cas system which was naturally coopted for guide RNA-directed transposition. Multiple novel adaptations were found specific to the I-D subtype, including natural inactivation of the Cas10 nuclease. The type I-D CRISPR-Cas transposition system showed flexibility in guide RNA length requirements and could be engineered to function with ribozyme-based self-processing guide RNAs removing the requirement for Cas6 in the heterologous system. The type I-D CRISPR-Cas transposon also has naturally fused transposase proteins that are functional for cut-and-paste transposition. Multiple attributes of the type I-D system offer unique possibilities for future work in gene editing. Our bioinformatic analysis also revealed a broader understanding of the evolution of Tn7-like elements. Extensive swapping of targeting systems was identified among Tn7-like elements in cyanobacteria and multiple examples of convergent evolution, including systems targeting integration into genes required for natural transformation.
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Affiliation(s)
- Shan-Chi Hsieh
- Department of Microbiology, Cornell University, Ithaca, NY 14853 USA
| | - Joseph E Peters
- Department of Microbiology, Cornell University, Ithaca, NY 14853 USA
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20
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Park JU, Tsai AWL, Rizo AN, Truong VH, Wellner TX, Schargel RD, Kellogg EH. Structures of the holo CRISPR RNA-guided transposon integration complex. Nature 2023; 613:775-782. [PMID: 36442503 PMCID: PMC9876797 DOI: 10.1038/s41586-022-05573-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/17/2022] [Indexed: 11/30/2022]
Abstract
CRISPR-associated transposons (CAST) are programmable mobile genetic elements that insert large DNA cargos using an RNA-guided mechanism1-3. CAST elements contain multiple conserved proteins: a CRISPR effector (Cas12k or Cascade), a AAA+ regulator (TnsC), a transposase (TnsA-TnsB) and a target-site-associated factor (TniQ). These components are thought to cooperatively integrate DNA via formation of a multisubunit transposition integration complex (transpososome). Here we reconstituted the approximately 1 MDa type V-K CAST transpososome from Scytonema hofmannii (ShCAST) and determined its structure using single-particle cryo-electon microscopy. The architecture of this transpososome reveals modular association between the components. Cas12k forms a complex with ribosomal subunit S15 and TniQ, stabilizing formation of a full R-loop. TnsC has dedicated interaction interfaces with TniQ and TnsB. Of note, we observe TnsC-TnsB interactions at the C-terminal face of TnsC, which contribute to the stimulation of ATPase activity. Although the TnsC oligomeric assembly deviates slightly from the helical configuration found in isolation, the TnsC-bound target DNA conformation differs markedly in the transpososome. As a consequence, TnsC makes new protein-DNA interactions throughout the transpososome that are important for transposition activity. Finally, we identify two distinct transpososome populations that differ in their DNA contacts near TniQ. This suggests that associations with the CRISPR effector can be flexible. This ShCAST transpososome structure enhances our understanding of CAST transposition systems and suggests ways to improve CAST transposition for precision genome-editing applications.
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Affiliation(s)
- Jung-Un Park
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Amy Wei-Lun Tsai
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Alexandrea N Rizo
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Vinh H Truong
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Tristan X Wellner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Richard D Schargel
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Elizabeth H Kellogg
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA.
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21
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Ramamurthy T, Ghosh A, Chowdhury G, Mukhopadhyay AK, Dutta S, Miyoshi SI. Deciphering the genetic network and programmed regulation of antimicrobial resistance in bacterial pathogens. Front Cell Infect Microbiol 2022; 12:952491. [PMID: 36506027 PMCID: PMC9727169 DOI: 10.3389/fcimb.2022.952491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 10/25/2022] [Indexed: 11/24/2022] Open
Abstract
Antimicrobial resistance (AMR) in bacteria is an important global health problem affecting humans, animals, and the environment. AMR is considered as one of the major components in the "global one health". Misuse/overuse of antibiotics in any one of the segments can impact the integrity of the others. In the presence of antibiotic selective pressure, bacteria tend to develop several defense mechanisms, which include structural changes of the bacterial outer membrane, enzymatic processes, gene upregulation, mutations, adaptive resistance, and biofilm formation. Several components of mobile genetic elements (MGEs) play an important role in the dissemination of AMR. Each one of these components has a specific function that lasts long, irrespective of any antibiotic pressure. Integrative and conjugative elements (ICEs), insertion sequence elements (ISs), and transposons carry the antimicrobial resistance genes (ARGs) on different genetic backbones. Successful transfer of ARGs depends on the class of plasmids, regulons, ISs proximity, and type of recombination systems. Additionally, phage-bacterial networks play a major role in the transmission of ARGs, especially in bacteria from the environment and foods of animal origin. Several other functional attributes of bacteria also get successfully modified to acquire ARGs. These include efflux pumps, toxin-antitoxin systems, regulatory small RNAs, guanosine pentaphosphate signaling, quorum sensing, two-component system, and clustered regularly interspaced short palindromic repeats (CRISPR) systems. The metabolic and virulence state of bacteria is also associated with a range of genetic and phenotypic resistance mechanisms. In spite of the availability of a considerable information on AMR, the network associations between selection pressures and several of the components mentioned above are poorly understood. Understanding how a pathogen resists and regulates the ARGs in response to antimicrobials can help in controlling the development of resistance. Here, we provide an overview of the importance of genetic network and regulation of AMR in bacterial pathogens.
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Affiliation(s)
- Thandavarayan Ramamurthy
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India,*Correspondence: Thandavarayan Ramamurthy,
| | - Amit Ghosh
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Goutam Chowdhury
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Asish K. Mukhopadhyay
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shanta Dutta
- Division of Bacteriology, ICMR-National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shin-inchi Miyoshi
- Collaborative Research Centre of Okayama University for Infectious Diseases at ICMR- National Institute of Cholera and Enteric Diseases, Kolkata, India,Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
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22
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Roberts A, Nethery MA, Barrangou R. Functional characterization of diverse type I-F CRISPR-associated transposons. Nucleic Acids Res 2022; 50:11670-11681. [PMID: 36384163 PMCID: PMC9723613 DOI: 10.1093/nar/gkac985] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 10/07/2022] [Accepted: 10/18/2022] [Indexed: 11/18/2022] Open
Abstract
CRISPR-Cas systems generally provide adaptive immunity in prokaryotes through RNA-guided degradation of foreign genetic elements like bacteriophages and plasmids. Recently, however, transposon-encoded and nuclease-deficient CRISPR-Cas systems were characterized and shown to be co-opted by Tn7-like transposons for CRISPR RNA-guided DNA transposition. As a genome engineering tool, these CRISPR-Cas systems and their associated transposon proteins can be deployed for programmable, site-specific integration of sizable cargo DNA, circumventing the need for DNA cleavage and homology-directed repair involving endogenous repair machinery. Here, we selected a diverse set of type I-F3 CRISPR-associated transposon systems derived from Gammaproteobacteria, predicted all components essential for transposition activity, and deployed them for functionality testing within Escherichia coli. Our results demonstrate that these systems possess a significant range of integration efficiencies with regards to temperature, transposon size, and flexible PAM requirements. Additionally, our findings support the categorization of these systems into functional compatibility groups for efficient and orthogonal RNA-guided DNA integration. This work expands the CRISPR-based toolbox with new CRISPR RNA-guided DNA integrases that can be applied to complex and extensive genome engineering efforts.
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Affiliation(s)
- Avery Roberts
- Genomic Sciences Graduate Program, North Carolina State University, Raleigh, NC 27695, USA,Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Matthew A Nethery
- Genomic Sciences Graduate Program, North Carolina State University, Raleigh, NC 27695, USA,Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC 27695, USA
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23
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Deep A, Gu Y, Gao YQ, Ego KM, Herzik MA, Zhou H, Corbett KD. The SMC-family Wadjet complex protects bacteria from plasmid transformation by recognition and cleavage of closed-circular DNA. Mol Cell 2022; 82:4145-4159.e7. [PMID: 36206765 PMCID: PMC9637719 DOI: 10.1016/j.molcel.2022.09.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 07/19/2022] [Accepted: 09/06/2022] [Indexed: 11/06/2022]
Abstract
Self versus non-self discrimination is a key element of innate and adaptive immunity across life. In bacteria, CRISPR-Cas and restriction-modification systems recognize non-self nucleic acids through their sequence and their methylation state, respectively. Here, we show that the Wadjet defense system recognizes DNA topology to protect its host against plasmid transformation. By combining cryoelectron microscopy with cross-linking mass spectrometry, we show that Wadjet forms a complex similar to the bacterial condensin complex MukBEF, with a novel nuclease subunit similar to a type II DNA topoisomerase. Wadjet specifically cleaves closed-circular DNA in a reaction requiring ATP hydrolysis by the structural maintenance of chromosome (SMC) ATPase subunit JetC, suggesting that the complex could use DNA loop extrusion to sense its substrate's topology, then specifically activate the nuclease subunit JetD to cleave plasmid DNA. Overall, our data reveal how bacteria have co-opted a DNA maintenance machine to specifically recognize and destroy foreign DNAs through topology sensing.
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Affiliation(s)
- Amar Deep
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yajie Gu
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yong-Qi Gao
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kaori M Ego
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Mark A Herzik
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Huilin Zhou
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kevin D Corbett
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
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24
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Tenjo-Castaño F, Sofos N, López-Méndez B, Stutzke LS, Fuglsang A, Stella S, Montoya G. Structure of the TnsB transposase-DNA complex of type V-K CRISPR-associated transposon. Nat Commun 2022; 13:5792. [PMID: 36184667 PMCID: PMC9527255 DOI: 10.1038/s41467-022-33504-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 09/20/2022] [Indexed: 11/17/2022] Open
Abstract
CRISPR-associated transposons (CASTs) are mobile genetic elements that co-opted CRISPR-Cas systems for RNA-guided transposition. Here we present the 2.4 Å cryo-EM structure of the Scytonema hofmannii (sh) TnsB transposase from Type V-K CAST, bound to the strand transfer DNA. The strand transfer complex displays an intertwined pseudo-symmetrical architecture. Two protomers involved in strand transfer display a catalytically competent active site composed by DDE residues, while other two, which play a key structural role, show active sites where the catalytic residues are not properly positioned for phosphodiester hydrolysis. Transposon end recognition is accomplished by the NTD1/2 helical domains. A singular in trans association of NTD1 domains of the catalytically competent subunits with the inactive DDE domains reinforces the assembly. Collectively, the structural features suggest that catalysis is coupled to protein-DNA assembly to secure proper DNA integration. DNA binding residue mutants reveal that lack of specificity decreases activity, but it could increase transposition in some cases. Our structure sheds light on the strand transfer reaction of DDE transposases and offers new insights into CAST transposition. The cryo-EM structure of the type VK CRISPR-associated TnsB transposase sheds light onto RNA-guided transposition, providing new possibilities to redesign CRISPR-associated transposon systems.
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Affiliation(s)
- Francisco Tenjo-Castaño
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark
| | - Nicholas Sofos
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark
| | - Blanca López-Méndez
- Protein Purification and Characterisation Facility, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark
| | - Luisa S Stutzke
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark
| | - Anders Fuglsang
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark
| | - Stefano Stella
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark.,Twelve Bio ApS, Ole Maaløes Vej 3, 2200, Copenhagen, Denmark
| | - Guillermo Montoya
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark.
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25
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Chuprikova L, Mateo-Cáceres V, de Toro M, Redrejo-Rodríguez M. ExplorePipolin: reconstruction and annotation of piPolB-encoding bacterial mobile elements from draft genomes. BIOINFORMATICS ADVANCES 2022; 2:vbac056. [PMID: 36699382 PMCID: PMC9710591 DOI: 10.1093/bioadv/vbac056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/18/2022] [Accepted: 08/06/2022] [Indexed: 01/28/2023]
Abstract
Motivation Detailed and accurate analysis of mobile genetic elements (MGEs) in bacteria is essential to deal with the current threat of multiresistant microbes. The overwhelming use of draft, contig-based genomes hinder the delineation of the genetic structure of these plastic and variable genomic stretches, as in the case of pipolins, a superfamily of MGEs that spans diverse integrative and plasmidic elements, characterized by the presence of a primer-independent DNA polymerase. Results ExplorePipolin is a Python-based pipeline that screens for the presence of the element and performs its reconstruction and annotation. The pipeline can be used on virtually any genome from diverse organisms and of diverse quality, obtaining the highest-scored possible structure and reconstructed out of different contigs if necessary. Then, predicted pipolin boundaries and pipolin encoded genes are subsequently annotated using a custom database, returning the standard file formats suitable for comparative genomics of this mobile element. Availability and implementation All code is available and can be accessed here: github.com/pipolinlab/ExplorePipolin. Supplementary information Supplementary data are available at Bioinformatics Advances online.
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Affiliation(s)
| | - V Mateo-Cáceres
- Department of Biochemistry, School of Medicine, Universidad Autónoma de Madrid and Instituto de Investigaciones Biomédicas ‘Alberto Sols’ (UAM-CSIC), Madrid, Spain
| | - M de Toro
- Plataforma de Genómica y Bioinformática, CIBIR (Centro de Investigación Biomédica de La Rioja), Logroño, La Rioja 26006, Spain
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Kaczmarska Z, Czarnocki-Cieciura M, Górecka-Minakowska KM, Wingo RJ, Jackiewicz J, Zajko W, Poznański JT, Rawski M, Grant T, Peters JE, Nowotny M. Structural basis of transposon end recognition explains central features of Tn7 transposition systems. Mol Cell 2022; 82:2618-2632.e7. [PMID: 35654042 PMCID: PMC9308760 DOI: 10.1016/j.molcel.2022.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 03/02/2022] [Accepted: 05/03/2022] [Indexed: 02/06/2023]
Abstract
Tn7 is a bacterial transposon with relatives containing element-encoded CRISPR-Cas systems mediating RNA-guided transposon insertion. Here, we present the 2.7 Å cryoelectron microscopy structure of prototypic Tn7 transposase TnsB interacting with the transposon end DNA. When TnsB interacts across repeating binding sites, it adopts a beads-on-a-string architecture, where the DNA-binding and catalytic domains are arranged in a tiled and intertwined fashion. The DNA-binding domains form few base-specific contacts leading to a binding preference that requires multiple weakly conserved sites at the appropriate spacing to achieve DNA sequence specificity. TnsB binding imparts differences in the global structure of the protein-bound DNA ends dictated by the spacing or overlap of binding sites explaining functional differences in the left and right ends of the element. We propose a model of the strand-transfer complex in which the terminal TnsB molecule is rearranged so that its catalytic domain is in a position conducive to transposition.
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Affiliation(s)
- Zuzanna Kaczmarska
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | - Mariusz Czarnocki-Cieciura
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | | | - Robert J Wingo
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA
| | - Justyna Jackiewicz
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | - Weronika Zajko
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland
| | - Jarosław T Poznański
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland
| | - Michał Rawski
- Malopolska Centre of Biotechnology, Jagiellonian University, 30-387 Krakow, Poland
| | - Timothy Grant
- John and Jeanne Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, WI 53715, USA; Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Joseph E Peters
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA.
| | - Marcin Nowotny
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, 02-109 Warsaw, Poland.
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27
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Benler S, Koonin EV. Recruitment of Mobile Genetic Elements for Diverse Cellular Functions in Prokaryotes. Front Mol Biosci 2022; 9:821197. [PMID: 35402511 PMCID: PMC8987985 DOI: 10.3389/fmolb.2022.821197] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 02/08/2022] [Indexed: 12/15/2022] Open
Abstract
Prokaryotic genomes are replete with mobile genetic elements (MGE) that span a continuum of replication autonomy. On numerous occasions during microbial evolution, diverse MGE lose their autonomy altogether but, rather than being quickly purged from the host genome, assume a new function that benefits the host, rendering the immobilized MGE subject to purifying selection, and resulting in its vertical inheritance. This mini-review highlights the diversity of the repurposed (exapted) MGE as well as the plethora of cellular functions that they perform. The principal contribution of the exaptation of MGE and their components is to the prokaryotic functional systems involved in biological conflicts, and in particular, defense against viruses and other MGE. This evolutionary entanglement between MGE and defense systems appears to stem both from mechanistic similarities and from similar evolutionary predicaments whereby both MGEs and defense systems tend to incur fitness costs to the hosts and thereby evolve mechanisms for survival including horizontal mobility, causing host addiction, and exaptation for functions beneficial to the host. The examples discussed demonstrate that the identity of an MGE, overall mobility and relationship with the host cell (mutualistic, symbiotic, commensal, or parasitic) are all factors that affect exaptation.
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28
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Klompe SE, Jaber N, Beh LY, Mohabir JT, Bernheim A, Sternberg SH. Evolutionary and mechanistic diversity of Type I-F CRISPR-associated transposons. Mol Cell 2022; 82:616-628.e5. [PMID: 35051352 PMCID: PMC8849592 DOI: 10.1016/j.molcel.2021.12.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 10/20/2021] [Accepted: 12/16/2021] [Indexed: 02/05/2023]
Abstract
Canonical CRISPR-Cas systems utilize RNA-guided nucleases for targeted cleavage of foreign nucleic acids, whereas some nuclease-deficient CRISPR-Cas complexes have been repurposed to direct the insertion of Tn7-like transposons. Here, we established a bioinformatic and experimental pipeline to comprehensively explore the diversity of Type I-F CRISPR-associated transposons. We report DNA integration for 20 systems and identify a highly active subset that exhibits complete orthogonality in transposon DNA mobilization. We reveal the modular nature of CRISPR-associated transposons by exploring the horizontal acquisition of targeting modules and by characterizing a system that encodes both a programmable, RNA-dependent pathway, and a fixed, RNA-independent pathway. Finally, we analyzed transposon-encoded cargo genes and found the striking presence of anti-phage defense systems, suggesting a role in transmitting innate immunity between bacteria. Collectively, this study substantially advances our biological understanding of CRISPR-associated transposon function and expands the suite of RNA-guided transposases for programmable, large-scale genome engineering.
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MESH Headings
- Bacterial Proteins/genetics
- Bacterial Proteins/metabolism
- CRISPR-Cas Systems
- Clustered Regularly Interspaced Short Palindromic Repeats
- DNA Transposable Elements/genetics
- DNA, Bacterial/genetics
- DNA, Bacterial/metabolism
- Escherichia coli/genetics
- Escherichia coli/immunology
- Escherichia coli/metabolism
- Evolution, Molecular
- Gene Editing
- Gene Expression Regulation, Bacterial
- Genetic Variation
- Immunity, Innate
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Guide, CRISPR-Cas Systems/genetics
- RNA, Guide, CRISPR-Cas Systems/metabolism
- Transposases/genetics
- Transposases/metabolism
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Affiliation(s)
- Sanne E Klompe
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Nora Jaber
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Leslie Y Beh
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Jason T Mohabir
- Department of Computer Science, Columbia University, New York, NY 10027, USA
| | - Aude Bernheim
- French National Institute of Health and Medical Research (INSERM), University of Paris, Paris, France
| | - Samuel H Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
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