1
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Benz F, Camara-Wilpert S, Russel J, Wandera KG, Čepaitė R, Ares-Arroyo M, Gomes-Filho JV, Englert F, Kuehn JA, Gloor S, Mestre MR, Cuénod A, Aguilà-Sans M, Maccario L, Egli A, Randau L, Pausch P, Rocha EPC, Beisel CL, Madsen JS, Bikard D, Hall AR, Sørensen SJ, Pinilla-Redondo R. Type IV-A3 CRISPR-Cas systems drive inter-plasmid conflicts by acquiring spacers in trans. Cell Host Microbe 2024; 32:875-886.e9. [PMID: 38754416 DOI: 10.1016/j.chom.2024.04.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 03/05/2024] [Accepted: 04/23/2024] [Indexed: 05/18/2024]
Abstract
Plasmid-encoded type IV-A CRISPR-Cas systems lack an acquisition module, feature a DinG helicase instead of a nuclease, and form ribonucleoprotein complexes of unknown biological functions. Type IV-A3 systems are carried by conjugative plasmids that often harbor antibiotic-resistance genes and their CRISPR array contents suggest a role in mediating inter-plasmid conflicts, but this function remains unexplored. Here, we demonstrate that a plasmid-encoded type IV-A3 system co-opts the type I-E adaptation machinery from its host, Klebsiella pneumoniae (K. pneumoniae), to update its CRISPR array. Furthermore, we reveal that robust interference of conjugative plasmids and phages is elicited through CRISPR RNA-dependent transcriptional repression. By silencing plasmid core functions, type IV-A3 impacts the horizontal transfer and stability of targeted plasmids, supporting its role in plasmid competition. Our findings shed light on the mechanisms and ecological function of type IV-A3 systems and demonstrate their practical efficacy for countering antibiotic resistance in clinically relevant strains.
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Affiliation(s)
- Fabienne Benz
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Synthetic Biology, Paris 75015, France; Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris 75015, France; Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark; Institute of Integrative Biology, Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Sarah Camara-Wilpert
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Jakob Russel
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Katharina G Wandera
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Rimvydė Čepaitė
- Life Sciences Center - European Molecular Biology Laboratory (LSC-EMBL) Partnership for Genome Editing Technologies, Vilnius University - Life Sciences Center, Vilnius University, Vilnius 10257, Lithuania
| | - Manuel Ares-Arroyo
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris 75015, France
| | | | - Frank Englert
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Johannes A Kuehn
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Silvana Gloor
- Institute of Integrative Biology, Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Mario Rodríguez Mestre
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Aline Cuénod
- Applied Microbiology Research, Department of Biomedicine, University of Basel, Basel, Switzerland; Division of Clinical Bacteriology and Mycology, University Hospital Basel, Basel, Switzerland; Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
| | - Mònica Aguilà-Sans
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Lorrie Maccario
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Adrian Egli
- Applied Microbiology Research, Department of Biomedicine, University of Basel, Basel, Switzerland; Division of Clinical Bacteriology and Mycology, University Hospital Basel, Basel, Switzerland; Institute of Medical Microbiology, University of Zurich, Zurich, Switzerland
| | - Lennart Randau
- Department of Biology, Philipps Universität Marburg, Marburg, Germany; SYNMIKRO, Center for Synthetic Microbiology, Marburg, Germany
| | - Patrick Pausch
- Life Sciences Center - European Molecular Biology Laboratory (LSC-EMBL) Partnership for Genome Editing Technologies, Vilnius University - Life Sciences Center, Vilnius University, Vilnius 10257, Lithuania
| | - Eduardo P C Rocha
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris 75015, France
| | - Chase L Beisel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany; Medical Faculty, University of Würzburg, Würzburg, Germany
| | - Jonas Stenløkke Madsen
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - David Bikard
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Synthetic Biology, Paris 75015, France
| | - Alex R Hall
- Institute of Integrative Biology, Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland
| | - Søren Johannes Sørensen
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark.
| | - Rafael Pinilla-Redondo
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark.
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Oh GS, An S, Kim S. Harnessing CRISPR-Cas adaptation for RNA recording and beyond. BMB Rep 2024; 57:40-49. [PMID: 38053290 PMCID: PMC10828431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 04/04/2023] [Accepted: 04/04/2023] [Indexed: 12/07/2023] Open
Abstract
Prokaryotes encode clustered regularly interspaced short palindromic repeat (CRISPR) arrays and CRISPR-associated (Cas) genes as an adaptive immune machinery. CRISPR-Cas systems effectively protect hosts from the invasion of foreign enemies, such as bacteriophages and plasmids. During a process called 'adaptation', non-self-nucleic acid fragments are acquired as spacers between repeats in the host CRISPR array, to establish immunological memory. The highly conserved Cas1-Cas2 complexes function as molecular recorders to integrate spacers in a time course manner, which can subsequently be expressed as crRNAs complexed with Cas effector proteins for the RNAguided interference pathways. In some of the RNA-targeting type III systems, Cas1 proteins are fused with reverse transcriptase (RT), indicating that RT-Cas1-Cas2 complexes can acquire RNA transcripts for spacer acquisition. In this review, we summarize current studies that focus on the molecular structure and function of the RT-fused Cas1-Cas2 integrase, and its potential applications as a directional RNA-recording tool in cells. Furthermore, we highlight outstanding questions for RT-Cas1-Cas2 studies and future directions for RNA-recording CRISPR technologies. [BMB Reports 2024; 57(1): 40-49].
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Affiliation(s)
- Gyeong-Seok Oh
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
| | - Seongjin An
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- Department of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea
| | - Sungchul Kim
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
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3
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Watts EA, Garrett SC, Catchpole RJ, Clark LM, Sanders TJ, Marshall CJ, Wenck BR, Vickerman RL, Santangelo TJ, Fuchs R, Robb B, Olson S, Graveley BR, Terns MP. Histones direct site-specific CRISPR spacer acquisition in model archaeon. Nat Microbiol 2023; 8:1682-1694. [PMID: 37550505 PMCID: PMC10823912 DOI: 10.1038/s41564-023-01446-3] [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: 10/27/2022] [Accepted: 07/11/2023] [Indexed: 08/09/2023]
Abstract
CRISPR-Cas systems provide heritable immunity against viruses and other mobile genetic elements by incorporating fragments of invader DNA into the host CRISPR array as spacers. Integration of new spacers is localized to the 5' end of the array, and in certain Gram-negative Bacteria this polarized localization is accomplished by the integration host factor. For most other Bacteria and Archaea, the mechanism for 5' end localization is unknown. Here we show that archaeal histones play a key role in directing integration of CRISPR spacers. In Pyrococcus furiosus, deletion of either histone A or B impairs integration. In vitro, purified histones are sufficient to direct integration to the 5' end of the CRISPR array. Archaeal histone tetramers and bacterial integration host factor induce similar U-turn bends in bound DNA. These findings indicate a co-evolution of CRISPR arrays with chromosomal DNA binding proteins and a widespread role for binding and bending of DNA to facilitate accurate spacer integration.
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4
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Dhingra Y, Sashital DG. Cas4/1 dual nuclease activities enable prespacer maturation and directional integration in a type I-G CRISPR-Cas system. J Biol Chem 2023; 299:105178. [PMID: 37607619 PMCID: PMC10504553 DOI: 10.1016/j.jbc.2023.105178] [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: 06/09/2023] [Revised: 08/12/2023] [Accepted: 08/15/2023] [Indexed: 08/24/2023] Open
Abstract
CRISPR-Cas adaptive immune systems uptake short "spacer" sequences from foreign DNA and incorporate them into the host genome to serve as templates for CRISPR RNAs that guide interference against future infections. Adaptation in CRISPR systems is mediated by Cas1-Cas2 complexes that catalyze integration of prespacer substrates into the CRISPR array. Many DNA targeting systems also require Cas4 endonucleases for functional spacer acquisition. Cas4 selects prespacers containing a protospacer adjacent motif (PAM) and removes the PAM prior to integration, both of which are required to ensure host immunization. Cas1 has also been shown to function as a nuclease in some systems, but a role for this nuclease activity in adaptation has not been demonstrated. We identified a type I-G Cas4/1 fusion with a nucleolytically active Cas1 domain that can directly participate in prespacer processing. The Cas1 domain is both an integrase and a sequence-independent nuclease that cleaves the non-PAM end of a prespacer, generating optimal overhang lengths that enable integration at the leader side. The Cas4 domain sequence specifically cleaves the PAM end of the prespacer, ensuring integration of the PAM end at the spacer side. The two domains have varying metal ion requirements. While Cas4 activity is Mn2+ dependent, Cas1 preferentially uses Mg2+ over Mn2+. The dual nuclease activity of Cas4/1 eliminates the need for additional factors in prespacer processing making the adaptation module self-reliant for prespacer maturation and directional integration.
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Affiliation(s)
- Yukti Dhingra
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, Iowa, USA
| | - Dipali G Sashital
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, Iowa, USA.
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5
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Dhingra Y, Sashital DG. Cas4/1 dual nuclease activities enable prespacer maturation and directional integration in a type I-G CRISPR-Cas system. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.05.543779. [PMID: 37333257 PMCID: PMC10274657 DOI: 10.1101/2023.06.05.543779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
CRISPR-Cas adaptive immune systems uptake short 'spacer' sequences from foreign DNA and incorporate them into the host genome to serve as templates for crRNAs that guide interference against future infections. Adaptation in CRISPR systems is mediated by Cas1-Cas2 complexes that catalyze integration of prespacer substrates into the CRISPR array. Many DNA targeting systems also require Cas4 endonucleases for functional spacer acquisition. Cas4 selects prespacers containing a protospacer adjacent motif (PAM) and removes the PAM prior to integration, both of which are required to ensure host immunization. Cas1 has also been shown to function as a nuclease in some systems, but a role for this nuclease activity in adaptation has not been demonstrated. We identified a type I-G Cas4/1 fusion with a nucleolytically active Cas1 domain that can directly participate in prespacer processing. The Cas1 domain is both an integrase and a sequence-independent nuclease that cleaves the non-PAM end of a prespacer, generating optimal overhang lengths that enable integration at the leader side. The Cas4 domain sequence-specifically cleaves the PAM end of the prespacer, ensuring integration of the PAM end at the spacer side. The two domains have varying metal ion requirements. While Cas4 activity is Mn 2+ dependent, Cas1 preferentially uses Mg 2+ over Mn 2+ . The dual nuclease activity of Cas4/1 eliminates the need for additional factors in prespacer processing, making the adaptation module self-reliant for prespacer maturation and directional integration.
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Affiliation(s)
- Yukti Dhingra
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, IA, USA
| | - Dipali G. Sashital
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, IA, USA
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6
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Lear SK, Lopez SC, González-Delgado A, Bhattarai-Kline S, Shipman SL. Temporally resolved transcriptional recording in E. coli DNA using a Retro-Cascorder. Nat Protoc 2023; 18:1866-1892. [PMID: 37059915 PMCID: PMC10631475 DOI: 10.1038/s41596-023-00819-6] [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: 08/31/2022] [Accepted: 02/09/2023] [Indexed: 04/16/2023]
Abstract
Biological signals occur over time in living cells. Yet most current approaches to interrogate biology, particularly gene expression, use destructive techniques that quantify signals only at a single point in time. A recent technological advance, termed the Retro-Cascorder, overcomes this limitation by molecularly logging a record of gene expression events in a temporally organized genomic ledger. The Retro-Cascorder works by converting a transcriptional event into a DNA barcode using a retron reverse transcriptase and then storing that event in a unidirectionally expanding clustered regularly interspaced short palindromic repeats (CRISPR) array via acquisition by CRISPR-Cas integrases. This CRISPR array-based ledger of gene expression can be retrieved at a later point in time by sequencing. Here we describe an implementation of the Retro-Cascorder in which the relative timing of transcriptional events from multiple promoters of interest is recorded chronologically in Escherichia coli populations over multiple days. We detail the molecular components required for this technology, provide a step-by-step guide to generate the recording and retrieve the data by Illumina sequencing, and give instructions for how to use custom software to infer the relative transcriptional timing from the sequencing data. The example recording is generated in 2 d, preparation of sequencing libraries and sequencing can be accomplished in 2-3 d, and analysis of data takes up to several hours. This protocol can be implemented by someone familiar with basic bacterial culture, molecular biology and bioinformatics. Analysis can be minimally run on a personal computer.
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Affiliation(s)
- Sierra K Lear
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA, USA
- UCSF-UCB Graduate Program in Bioengineering, University of California, Berkeley, CA, USA
| | - Santiago C Lopez
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA, USA
- UCSF-UCB Graduate Program in Bioengineering, University of California, Berkeley, CA, USA
| | | | - Santi Bhattarai-Kline
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA, USA
- UCLA-Caltech Medical Scientist Training Program, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Seth L Shipman
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA, USA.
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
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7
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CRISPR-Cas adaptation in Escherichia coli. Biosci Rep 2023; 43:232582. [PMID: 36809461 PMCID: PMC10011333 DOI: 10.1042/bsr20221198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/20/2023] [Accepted: 02/21/2023] [Indexed: 02/23/2023] Open
Abstract
Prokaryotes use the adaptive immunity mediated via the Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR associated (CRISPR-Cas) system for protection against invading elements such as phages and plasmids. The immunity is achieved by capturing small DNA fragments or spacers from foreign nucleic acids (protospacers) and integrating them into the host CRISPR locus. This step of CRISPR-Cas immunity called 'naïve CRISPR adaptation' requires the conserved Cas1-Cas2 complex and is often supported by variable host proteins that assist in spacer processing and integration. Bacteria that have acquired new spacers become immune to the same invading elements when reinfected. CRISPR-Cas immunity can also be updated by integrating new spacers from the same invading elements, a process called 'primed adaptation'. Only properly selected and integrated spacers are functional in the next steps of CRISPR immunity when their processed transcripts are used for RNA-guided target recognition and interference (target degradation). Capturing, trimming, and integrating new spacers in the correct orientation are universal steps of adaptation to all CRISPR-Cas systems, but some details are CRISPR-Cas type-specific and species-specific. In this review, we provide an overview of the mechanisms of CRISPR-Cas class 1 type I-E adaptation in Escherichia coli as a general model for adaptation processes (DNA capture and integration) that have been studied in detail. We focus on the role of host non-Cas proteins involved in adaptation, particularly on the role of homologous recombination.
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8
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Lear SK, Shipman SL. Molecular recording: transcriptional data collection into the genome. Curr Opin Biotechnol 2023; 79:102855. [PMID: 36481341 PMCID: PMC10547096 DOI: 10.1016/j.copbio.2022.102855] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 11/08/2022] [Accepted: 11/14/2022] [Indexed: 12/12/2022]
Abstract
Advances in regenerative medicine depend upon understanding the complex transcriptional choreography that guides cellular development. Transcriptional molecular recorders, tools that record different transcriptional events into the genome of cells, hold promise to elucidate both the intensity and timing of transcriptional activity at single-cell resolution without requiring destructive multitime point assays. These technologies are dependent on DNA writers, which translate transcriptional signals into stable genomic mutations that encode the duration, intensity, and order of transcriptional events. In this review, we highlight recent progress toward more informative and multiplexable transcriptional recording through the use of three different types of DNA writing - recombineering, Cas1-Cas2 acquisition, and prime editing - and the architecture of the genomic data generated.
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Affiliation(s)
- Sierra K Lear
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA, USA; Graduate Program in Bioengineering, University of California, San Francisco and Berkeley, CA, USA
| | - Seth L Shipman
- Gladstone Institute of Data Science and Biotechnology, San Francisco, CA, USA; Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA, USA; Chan Zuckerberg Biohub, San Francisco, CA, USA.
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9
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Flusche T, Rajan R. Molecular Details of DNA Integration by CRISPR-Associated Proteins During Adaptation in Bacteria and Archaea. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1414:27-43. [PMID: 35852729 DOI: 10.1007/5584_2022_730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins constitute an adaptive immune system in bacteria and archaea, where immunological memory is retained in the CRISPR locus as short pieces of the intruding nucleic acid, termed spacers. The adaptation to new infections occurs through the integration of a new spacer into the CRISPR array. For immune protection, spacers are transcribed into CRISPR RNAs (crRNA) that are used to guide the effector nuclease of the system in sequence-dependent target cleavage. Spacers originate as a prespacer from either DNA or RNA depending on the CRISPR-Cas system being observed, and the nearly universal Cas proteins, Cas1 and Cas2, insert the prespacer into the CRISPR locus during adaptation in all systems that contain them. The mechanism of site-specific prespacer integration varies across CRISPR classes and types, and distinct differences can even be found within the same subtype. In this review, the current knowledge on the mechanisms of prespacer integration in type II-A CRISPR-Cas systems will be described. Comparisons of the currently characterized type II-A systems show that distinct mechanisms exist within different members of this subtype and are correlated to sequence-specific interactions of Cas proteins and the DNA elements present in the CRISPR array. These observations indicate that nature has fine-tuned the mechanistic details while performing the basic step of DNA integration by Cas proteins, which offers unique advantages to develop Cas1-Cas2-based biotechnology.
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Affiliation(s)
- Tamara Flusche
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, OK, USA
| | - Rakhi Rajan
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, OK, USA.
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10
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Dhingra Y, Suresh SK, Juneja P, Sashital DG. PAM binding ensures orientational integration during Cas4-Cas1-Cas2-mediated CRISPR adaptation. Mol Cell 2022; 82:4353-4367.e6. [PMID: 36272411 PMCID: PMC9675710 DOI: 10.1016/j.molcel.2022.09.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 08/10/2022] [Accepted: 09/28/2022] [Indexed: 11/06/2022]
Abstract
Adaptation in CRISPR-Cas systems immunizes bacteria and archaea against mobile genetic elements. In many DNA-targeting systems, the Cas4-Cas1-Cas2 complex is required for selection and processing of DNA segments containing PAM sequences prior to integration of these "prespacer" substrates as spacers in the CRISPR array. We determined cryo-EM structures of the Cas4-Cas1-Cas2 adaptation complex from the type I-C system that encodes standalone Cas1 and Cas4 proteins. The structures reveal how Cas4 specifically reads out bases within the PAM sequence and how interactions with both Cas1 and Cas2 activate Cas4 endonuclease activity. The Cas4-PAM interaction ensures tight binding between the adaptation complex and the prespacer, significantly enhancing integration of the non-PAM end into the CRISPR array and ensuring correct spacer orientation. Corroborated with our biochemical results, Cas4-Cas1-Cas2 structures with substrates representing various stages of CRISPR adaptation reveal a temporally resolved mechanism for maturation and integration of functional spacers into the CRISPR array.
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Affiliation(s)
- Yukti Dhingra
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, IA, USA
| | - Shravanti K Suresh
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, IA, USA
| | - Puneet Juneja
- Cryo-EM Facility, Office of Biotechnology, Iowa State University, Ames, IA, USA
| | - Dipali G Sashital
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, IA, USA.
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11
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DNA Motifs and an Accessory CRISPR Factor Determine Cas1 Binding and Integration Activity in Sulfolobus islandicus. Int J Mol Sci 2022; 23:ijms231710178. [PMID: 36077578 PMCID: PMC9456107 DOI: 10.3390/ijms231710178] [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] [Received: 08/19/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 11/17/2022] Open
Abstract
CRISPR-Cas systems empower prokaryotes with adaptive immunity against invasive mobile genetic elements. At the first step of CRISPR immunity adaptation, short DNA fragments from the invaders are integrated into CRISPR arrays at the leader-proximal end. To date, the mechanism of recognition of the leader-proximal end remains largely unknown. Here, in the Sulfolobus islandicus subtype I-A system, we show that mutations destroying the proximal region reduce CRISPR adaptation in vivo. We identify that a stem-loop structure is present on the leader-proximal end, and we demonstrate that Cas1 preferentially binds the stem-loop structure in vitro. Moreover, we demonstrate that the integrase activity of Cas1 is modulated by interacting with a CRISPR-associated factor Csa3a. When translocated to the CRISPR array, the Csa3a-Cas1 complex is separated by Csa3a binding to the leader-distal motif and Cas1 binding to the leader-proximal end. Mutation at the leader-distal motif reduces CRISPR adaptation efficiency, further confirming the in vivo function of leader-distal motif. Together, our results suggest a general model for binding of Cas1 protein to a leader motif and modulation of integrase activity by an accessory factor.
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12
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Zhang X, An X. Adaptation by Type III CRISPR-Cas Systems: Breakthrough Findings and Open Questions. Front Microbiol 2022; 13:876174. [PMID: 35495695 PMCID: PMC9048733 DOI: 10.3389/fmicb.2022.876174] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 03/03/2022] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas systems acquire heritable defense memory against invading nucleic acids through adaptation. Type III CRISPR-Cas systems have unique and intriguing features of defense and are important in method development for Genetics research. We started to understand the common and unique properties of type III CRISPR-Cas adaptation in recent years. This review summarizes our knowledge regarding CRISPR-Cas adaptation with the emphasis on type III systems and discusses open questions for type III adaptation studies.
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Affiliation(s)
- Xinfu Zhang
- Department of Biochemistry and Molecular Biology, The University of Georgia, Athens, GA, United States
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Research Center of Tree breeding and Ecological Remediation, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- *Correspondence: Xinfu Zhang,
| | - Xinmin An
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Research Center of Tree breeding and Ecological Remediation, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- Xinmin An,
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13
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Lee H, Sashital DG. Creating memories: molecular mechanisms of CRISPR adaptation. Trends Biochem Sci 2022; 47:464-476. [DOI: 10.1016/j.tibs.2022.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/06/2022] [Accepted: 02/07/2022] [Indexed: 12/22/2022]
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14
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Guzmán NM, Esquerra-Ruvira B, Mojica FJM. Digging into the lesser-known aspects of CRISPR biology. Int Microbiol 2021; 24:473-498. [PMID: 34487299 PMCID: PMC8616872 DOI: 10.1007/s10123-021-00208-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 12/26/2022]
Abstract
A long time has passed since regularly interspaced DNA repeats were discovered in prokaryotes. Today, those enigmatic repetitive elements termed clustered regularly interspaced short palindromic repeats (CRISPR) are acknowledged as an emblematic part of multicomponent CRISPR-Cas (CRISPR associated) systems. These systems are involved in a variety of roles in bacteria and archaea, notably, that of conferring protection against transmissible genetic elements through an adaptive immune-like response. This review summarises the present knowledge on the diversity, molecular mechanisms and biology of CRISPR-Cas. We pay special attention to the most recent findings related to the determinants and consequences of CRISPR-Cas activity. Research on the basic features of these systems illustrates how instrumental the study of prokaryotes is for understanding biology in general, ultimately providing valuable tools for diverse fields and fuelling research beyond the mainstream.
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Affiliation(s)
- Noemí M Guzmán
- Dpto. Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Belén Esquerra-Ruvira
- Dpto. Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Francisco J M Mojica
- Dpto. Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain. .,Instituto Multidisciplinar para el Estudio del Medio, Universidad de Alicante, Alicante, Spain.
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15
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Liu Q, Wang S, Long J, Chen Z, Yang B, Lin F. Functional Identification of the Xanthomonas oryzae pv. oryzae Type I-C CRISPR-Cas System and Its Potential in Gene Editing Application. Front Microbiol 2021; 12:686715. [PMID: 34475857 PMCID: PMC8406640 DOI: 10.3389/fmicb.2021.686715] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 07/26/2021] [Indexed: 12/19/2022] Open
Abstract
The type I clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system is one of five adaptive immune systems and exists widely in bacteria and archaea. In this study, we showed that Xanthomonas oryzae pv. oryzae (Xoo) possesses a functional CRISPR system by engineering constructs mimicking its CRISPR cassette. CRISPR array analysis showed that the TTC at the 5'-end of the target sequence is a functional protospacer-adjacent motif (PAM) of CRISPR. Guide RNA (gRNA) deletion analysis identified a minimum of 27-bp spacer that was required to ensure successful self-target killing in PXO99A strain. Mutants with deletion of individual Cas genes were constructed to analyze the effects of Cas proteins on mature CRISPR RNA (crRNA), processing intermediates and DNA interference. Results showed that depleting each of the three genes, cas5d, csd1, and csd2 inactivated the pre-crRNA processing, whereas inactivation of cas3 impaired in processing pre-crRNA. Furthermore, the Xoo CRISPR/Cas system was functional in Pseudomonas syringae pv. tomato. Collectively, our results would contribute to the functional study of CRISPR/Cas system of Xoo, and also provide a new vision on the use of bacterial endogenous systems as a convenient tool for gene editing.
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Affiliation(s)
- Qibing Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources/Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou, China
| | - Siwei Wang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources/Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou, China
| | - Juying Long
- Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Zhuoyue Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources/Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou, China
| | - Bing Yang
- Division of Plant Sciences, Bond Life Sciences Center, University of Missouri, Columbia, MO, United States.,Donald Danforth Plant Science Center, St. Louis, MO, United States
| | - Fei Lin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources/Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou, China
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16
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Santiago-Frangos A, Buyukyoruk M, Wiegand T, Krishna P, Wiedenheft B. Distribution and phasing of sequence motifs that facilitate CRISPR adaptation. Curr Biol 2021; 31:3515-3524.e6. [PMID: 34174210 PMCID: PMC8552246 DOI: 10.1016/j.cub.2021.05.068] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 04/30/2021] [Accepted: 05/28/2021] [Indexed: 12/11/2022]
Abstract
CRISPR-associated proteins (Cas1 and Cas2) integrate foreign DNA at the "leader" end of CRISPR loci. Several CRISPR leader sequences are reported to contain a binding site for a DNA-bending protein called integration host factor (IHF). IHF-induced DNA bending kinks the leader of type I-E CRISPRs, recruiting an upstream sequence motif that helps dock Cas1-2 onto the first repeat of the CRISPR locus. To determine the prevalence of IHF-directed CRISPR adaptation, we analyzed 15,274 bacterial and archaeal CRISPR leaders. These experiments reveal multiple IHF binding sites and diverse upstream sequence motifs in a subset of the I-C, I-E, I-F, and II-C CRISPR leaders. We identify subtype-specific motifs and show that the phase of these motifs is critical for CRISPR adaptation. Collectively, this work clarifies the prevalence and mechanism(s) of IHF-dependent CRISPR adaptation and suggests that leader sequences and adaptation proteins may coevolve under the selective pressures of foreign genetic elements like plasmids or phages.
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Affiliation(s)
| | - Murat Buyukyoruk
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Tanner Wiegand
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Pushya Krishna
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Blake Wiedenheft
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA.
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17
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Zabrady K, Zabrady M, Kolesar P, Li AWH, Doherty AJ. CRISPR-Associated Primase-Polymerases are implicated in prokaryotic CRISPR-Cas adaptation. Nat Commun 2021; 12:3690. [PMID: 34140468 PMCID: PMC8211822 DOI: 10.1038/s41467-021-23535-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 05/04/2021] [Indexed: 12/24/2022] Open
Abstract
CRISPR-Cas pathways provide prokaryotes with acquired “immunity” against foreign genetic elements, including phages and plasmids. Although many of the proteins associated with CRISPR-Cas mechanisms are characterized, some requisite enzymes remain elusive. Genetic studies have implicated host DNA polymerases in some CRISPR-Cas systems but CRISPR-specific replicases have not yet been discovered. We have identified and characterised a family of CRISPR-Associated Primase-Polymerases (CAPPs) in a range of prokaryotes that are operonically associated with Cas1 and Cas2. CAPPs belong to the Primase-Polymerase (Prim-Pol) superfamily of replicases that operate in various DNA repair and replication pathways that maintain genome stability. Here, we characterise the DNA synthesis activities of bacterial CAPP homologues from Type IIIA and IIIB CRISPR-Cas systems and establish that they possess a range of replicase activities including DNA priming, polymerisation and strand-displacement. We demonstrate that CAPPs operonically-associated partners, Cas1 and Cas2, form a complex that possesses spacer integration activity. We show that CAPPs physically associate with the Cas proteins to form bespoke CRISPR-Cas complexes. Finally, we propose how CAPPs activities, in conjunction with their partners, may function to undertake key roles in CRISPR-Cas adaptation. CAPPs are putative Primase-Polymerases associated with CRISPR-Cas operons. Here, the authors show CAPPs genetic and physical association with Cas1 and Cas2, their capacity to function as DNA-dependent DNA primases and DNA polymerases, and that Cas1-Cas2 complex adjacent to CAPP has bona fide spacer integration activity.
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Affiliation(s)
- Katerina Zabrady
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, UK
| | - Matej Zabrady
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, UK
| | - Peter Kolesar
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, UK.,National Centre for Biomolecular Research, Masaryk University, Brno, Czech Republic
| | - Arthur W H Li
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, UK
| | - Aidan J Doherty
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, UK.
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18
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Abstract
Prokaryotes have developed numerous defense strategies to combat the constant threat posed by the diverse genetic parasites that endanger them. Clustered regularly interspaced short palindromic repeat (CRISPR)-Cas loci guard their hosts with an adaptive immune system against foreign nucleic acids. Protection starts with an immunization phase, in which short pieces of the invader's genome, known as spacers, are captured and integrated into the CRISPR locus after infection. Next, during the targeting phase, spacers are transcribed into CRISPR RNAs (crRNAs) that guide CRISPR-associated (Cas) nucleases to destroy the invader's DNA or RNA. Here we describe the many different molecular mechanisms of CRISPR targeting and how they are interconnected with the immunization phase through a third phase of the CRISPR-Cas immune response: primed spacer acquisition. In this phase, Cas proteins direct the crRNA-guided acquisition of additional spacers to achieve a more rapid and robust immunization of the population.
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Affiliation(s)
- Philip M. Nussenzweig
- Laboratory of Bacteriology, The Rockefeller University, New York, NY 10065, USA
- Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10065, USA
| | - Luciano A. Marraffini
- Laboratory of Bacteriology, The Rockefeller University, New York, NY 10065, USA
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
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19
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Zink IA, Wimmer E, Schleper C. Heavily Armed Ancestors: CRISPR Immunity and Applications in Archaea with a Comparative Analysis of CRISPR Types in Sulfolobales. Biomolecules 2020; 10:E1523. [PMID: 33172134 PMCID: PMC7694759 DOI: 10.3390/biom10111523] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/31/2020] [Accepted: 11/03/2020] [Indexed: 12/13/2022] Open
Abstract
Prokaryotes are constantly coping with attacks by viruses in their natural environments and therefore have evolved an impressive array of defense systems. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is an adaptive immune system found in the majority of archaea and about half of bacteria which stores pieces of infecting viral DNA as spacers in genomic CRISPR arrays to reuse them for specific virus destruction upon a second wave of infection. In detail, small CRISPR RNAs (crRNAs) are transcribed from CRISPR arrays and incorporated into type-specific CRISPR effector complexes which further degrade foreign nucleic acids complementary to the crRNA. This review gives an overview of CRISPR immunity to newcomers in the field and an update on CRISPR literature in archaea by comparing the functional mechanisms and abundances of the diverse CRISPR types. A bigger fraction is dedicated to the versatile and prevalent CRISPR type III systems, as tremendous progress has been made recently using archaeal models in discerning the controlled molecular mechanisms of their unique tripartite mode of action including RNA interference, DNA interference and the unique cyclic-oligoadenylate signaling that induces promiscuous RNA shredding by CARF-domain ribonucleases. The second half of the review spotlights CRISPR in archaea outlining seminal in vivo and in vitro studies in model organisms of the euryarchaeal and crenarchaeal phyla, including the application of CRISPR-Cas for genome editing and gene silencing. In the last section, a special focus is laid on members of the crenarchaeal hyperthermophilic order Sulfolobales by presenting a thorough comparative analysis about the distribution and abundance of CRISPR-Cas systems, including arrays and spacers as well as CRISPR-accessory proteins in all 53 genomes available to date. Interestingly, we find that CRISPR type III and the DNA-degrading CRISPR type I complexes co-exist in more than two thirds of these genomes. Furthermore, we identified ring nuclease candidates in all but two genomes and found that they generally co-exist with the above-mentioned CARF domain ribonucleases Csx1/Csm6. These observations, together with published literature allowed us to draft a working model of how CRISPR-Cas systems and accessory proteins cross talk to establish native CRISPR anti-virus immunity in a Sulfolobales cell.
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20
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Kieper SN, Almendros C, Brouns SJJ. Conserved motifs in the CRISPR leader sequence control spacer acquisition levels in Type I-D CRISPR-Cas systems. FEMS Microbiol Lett 2020; 366:5525085. [PMID: 31252430 PMCID: PMC6607411 DOI: 10.1093/femsle/fnz129] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 06/27/2019] [Indexed: 12/20/2022] Open
Abstract
Integrating short DNA fragments at the correct leader-repeat junction is key to successful CRISPR-Cas memory formation. The Cas1-2 proteins are responsible to carry out this process. However, the CRISPR adaptation process additionally requires a DNA element adjacent to the CRISPR array, called leader, to facilitate efficient localization of the correct integration site. In this work, we introduced the core CRISPR adaptation genes cas1 and cas2 from the Type I-D CRISPR-Cas system of Synechocystis sp. 6803 into Escherichia coli and assessed spacer integration efficiency. Truncation of the leader resulted in a significant reduction of spacer acquisition levels and revealed the importance of different conserved regions for CRISPR adaptation rates. We found three conserved sequence motifs in the leader of I-D CRISPR arrays that each affected spacer acquisition rates, including an integrase anchoring site. Our findings support the model in which the leader sequence is an integral part of type I-D adaptation in Synechocystis sp. acting as a localization signal for the adaptation complex to drive CRISPR adaptation at the first repeat of the CRISPR array.
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Affiliation(s)
- Sebastian N Kieper
- Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Cristóbal Almendros
- Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Stan J J Brouns
- Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands.,Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
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21
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Nimkar S, Anand B. Cas3/I-C mediated target DNA recognition and cleavage during CRISPR interference are independent of the composition and architecture of Cascade surveillance complex. Nucleic Acids Res 2020; 48:2486-2501. [PMID: 31980818 PMCID: PMC7049708 DOI: 10.1093/nar/gkz1218] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 12/17/2019] [Accepted: 01/22/2020] [Indexed: 12/26/2022] Open
Abstract
In type I CRISPR-Cas system, Cas3—a nuclease cum helicase—in cooperation with Cascade surveillance complex cleaves the target DNA. Unlike the Cascade/I-E, which is composed of five subunits, the Cascade/I-C is made of only three subunits lacking the CRISPR RNA processing enzyme Cas6, whose role is assumed by Cas5. How these differences in the composition and organization of Cascade subunits in type I-C influence the Cas3/I-C binding and its target cleavage mechanism is poorly understood. Here, we show that Cas3/I-C is intrinsically a single-strand specific promiscuous nuclease. Apart from the helicase domain, a constellation of highly conserved residues—which are unique to type I-C—located in the uncharacterized C-terminal domain appears to influence the nuclease activity. Recruited by Cascade/I-C, the HD nuclease of Cas3/I-C nicks the single-stranded region of the non-target strand and positions the helicase motor. Powered by ATP, the helicase motor reels in the target DNA, until it encounters the roadblock en route, which stimulates the HD nuclease. Remarkably, we show that Cas3/I-C supplants Cas3/I-E for CRISPR interference in type I-E in vivo, suggesting that the target cleavage mechanism is evolutionarily conserved between type I-C and type I-E despite the architectural difference exhibited by Cascade/I-C and Cascade/I-E.
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Affiliation(s)
- Siddharth Nimkar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - B Anand
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
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22
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The structural basis of African swine fever virus pA104R binding to DNA and its inhibition by stilbene derivatives. Proc Natl Acad Sci U S A 2020; 117:11000-11009. [PMID: 32358196 DOI: 10.1073/pnas.1922523117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
African swine fever virus (ASFV) is a highly contagious nucleocytoplasmic large DNA virus (NCLDV) that causes nearly 100% mortality in swine. The development of effective vaccines and drugs against this virus is urgently needed. pA104R, an ASFV-derived histone-like protein, shares sequence and functional similarity with bacterial HU/IHF family members and is essential for viral replication. Herein, we solved the crystal structures of pA104R in its apo state as well as in complex with DNA. Apo-pA104R forms a homodimer and folds into an architecture conserved in bacterial heat-unstable nucleoid proteins/integration host factors (HUs/IHFs). The pA104R-DNA complex structure, however, uncovers that pA104R has a DNA binding pattern distinct from its bacterial homologs, that is, the β-ribbon arms of pA104R stabilize DNA binding by contacting the major groove instead of the minor groove. Mutations of the basic residues at the base region of the β-strand DNA binding region (BDR), rather than those in the β-ribbon arms, completely abolished DNA binding, highlighting the major role of the BDR base in DNA binding. An overall DNA bending angle of 93.8° is observed in crystal packing of the pA104R-DNA complex structure, which is close to the DNA bending angle in the HU-DNA complex. Stilbene derivatives SD1 and SD4 were shown to disrupt the binding between pA104R and DNA and inhibit the replication of ASFV in primary porcine alveolar macrophages. Collectively, these results reveal the structural basis of pA104R binding to DNA highlighting the importance of the pA104R-DNA interaction in the ASFV replication cycle and provide inhibitor leads for ASFV chemotherapy.
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23
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Pinilla-Redondo R, Mayo-Muñoz D, Russel J, Garrett RA, Randau L, Sørensen SJ, Shah SA. Type IV CRISPR-Cas systems are highly diverse and involved in competition between plasmids. Nucleic Acids Res 2020; 48:2000-2012. [PMID: 31879772 PMCID: PMC7038947 DOI: 10.1093/nar/gkz1197] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/02/2019] [Accepted: 12/13/2019] [Indexed: 12/18/2022] Open
Abstract
CRISPR-Cas systems provide prokaryotes with adaptive immune functions against viruses and other genetic parasites. In contrast to all other types of CRISPR-Cas systems, type IV has remained largely overlooked. Here, we describe a previously uncharted diversity of type IV gene cassettes, primarily encoded by plasmid-like elements from diverse prokaryotic taxa. Remarkably, via a comprehensive analysis of their CRISPR spacer content, these systems were found to exhibit a strong bias towards the targeting of other plasmids. Our data indicate that the functions of type IV systems have diverged from those of other host-related CRISPR-Cas immune systems to adopt a role in mediating conflicts between plasmids. Furthermore, we find evidence for cross-talk between certain type IV and type I CRISPR-Cas systems that co-exist intracellularly, thus providing a simple answer to the enigmatic absence of type IV adaptation modules. Collectively, our results lead to the expansion and reclassification of type IV systems and provide novel insights into the biological function and evolution of these elusive systems.
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Affiliation(s)
- Rafael Pinilla-Redondo
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
- Department of Technological Educations, University College Copenhagen, Sigurdsgade 26, 2200 Copenhagen, Denmark
| | - David Mayo-Muñoz
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Jakob Russel
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Roger A Garrett
- Danish Archaea Centre, Department of Biology, University of Copenhagen, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark
| | - Lennart Randau
- Philipps-Universität Marburg, Faculty of Biology, Hans-Meerwein-Straße 6, 35032 Marburg, Germany
| | - Søren J Sørensen
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Shiraz A Shah
- Copenhagen Prospective Studies on Asthma in Childhood (COPSAC), Herlev and Gentofte Hospital, University of Copenhagen, Ledreborg Alle 34, 2820 Gentofte, Denmark
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24
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Yoganand KN, Muralidharan M, Nimkar S, Anand B. Fidelity of prespacer capture and processing is governed by the PAM-mediated interactions of Cas1-2 adaptation complex in CRISPR-Cas type I-E system. J Biol Chem 2019; 294:20039-20053. [PMID: 31748409 PMCID: PMC6937570 DOI: 10.1074/jbc.ra119.009438] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 11/18/2019] [Indexed: 12/11/2022] Open
Abstract
Prokaryotes deploy CRISPR-Cas-based RNA-guided adaptive immunity to fend off mobile genetic elements such as phages and plasmids. During CRISPR adaptation, which is the first stage of CRISPR immunity, the Cas1-2 integrase complex captures invader-derived prespacer DNA and specifically integrates it at the leader-repeat junction as spacers. For this integration, several variants of CRISPR-Cas systems use Cas4 as an indispensable nuclease for selectively processing the protospacer adjacent motif (PAM) containing prespacers to a defined length. Surprisingly, however, a few CRISPR-Cas systems, such as type I-E, are bereft of Cas4. Despite the absence of Cas4, how the prespacers show impeccable conservation for length and PAM selection in type I-E remains intriguing. Here, using in vivo and in vitro integration assays, deep sequencing, and exonuclease footprinting, we show that Cas1-2/I-E-via the type I-E-specific extended C-terminal tail of Cas1-displays intrinsic affinity for PAM containing prespacers of variable length in Escherichia coli Although Cas1-2/I-E does not prune the prespacers, its binding protects the prespacer boundaries from exonuclease action. This ensures the pruning of exposed ends by exonucleases to aptly sized substrates for integration into the CRISPR locus. In summary, our work reveals that in a few CRISPR-Cas variants, such as type I-E, the specificity of PAM selection resides with Cas1-2, whereas the prespacer processing is co-opted by cellular non-Cas exonucleases, thereby offsetting the need for Cas4.
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Affiliation(s)
- Kakimani Nagarajan Yoganand
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Manasasri Muralidharan
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Siddharth Nimkar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Baskaran Anand
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
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25
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Grainy J, Garrett S, Graveley BR, P Terns M. CRISPR repeat sequences and relative spacing specify DNA integration by Pyrococcus furiosus Cas1 and Cas2. Nucleic Acids Res 2019; 47:7518-7531. [PMID: 31219587 PMCID: PMC6698737 DOI: 10.1093/nar/gkz548] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 06/07/2019] [Accepted: 06/12/2019] [Indexed: 12/26/2022] Open
Abstract
Acquiring foreign spacer DNA into the CRISPR locus is an essential primary step of the CRISPR-Cas pathway in prokaryotes for developing host immunity to mobile genetic elements. Here, we investigate spacer integration in vitro using proteins from Pyrococcus furiosus and demonstrate that Cas1 and Cas2 are sufficient to accurately integrate spacers into a minimal CRISPR locus. Using high-throughput sequencing, we identified high frequency spacer integration occurring at the same CRISPR repeat border sites utilized in vivo, as well as at several non-CRISPR plasmid sequences which share features with repeats. Analysis of non-CRISPR integration sites revealed that Cas1 and Cas2 are directed to catalyze full-site spacer integration at specific DNA stretches where guanines and/or cytosines are 30 base pairs apart and the intervening sequence harbors several positionally conserved bases. Moreover, assaying a series of CRISPR repeat mutations, followed by sequencing of the integration products, revealed that the specificity of integration is primarily directed by sequences at the leader-repeat junction as well as an adenine-rich sequence block in the mid-repeat. Together, our results indicate that P. furiosus Cas1 and Cas2 recognize multiple sequence features distributed over a 30 base pair DNA region for accurate spacer integration at the CRISPR repeat.
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Affiliation(s)
- Julie Grainy
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Sandra Garrett
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn Stem Cell Institute, UConn Health, Farmington, CT 06030, USA
| | - Brenton R Graveley
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn Stem Cell Institute, UConn Health, Farmington, CT 06030, USA
| | - Michael P Terns
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA.,Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.,Department of Genetics, University of Georgia, Athens, GA 30602, USA
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26
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Kim JG, Garrett S, Wei Y, Graveley BR, Terns MP. CRISPR DNA elements controlling site-specific spacer integration and proper repeat length by a Type II CRISPR-Cas system. Nucleic Acids Res 2019; 47:8632-8648. [PMID: 31392984 PMCID: PMC6895254 DOI: 10.1093/nar/gkz677] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/19/2019] [Accepted: 07/30/2019] [Indexed: 12/26/2022] Open
Abstract
CRISPR–Cas systems provide heritable immunity against viruses by capturing short invader DNA sequences, termed spacers, and incorporating them into the CRISPR loci of the prokaryotic host genome. Here, we investigate DNA elements that control accurate spacer uptake in the type II-A CRISPR locus of Streptococcus thermophilus. We determined that purified Cas1 and Cas2 proteins catalyze spacer integration with high specificity for CRISPR repeat junctions. We show that 10 bp of the CRISPR leader sequence is critical for stimulating polarized integration preferentially at the repeat proximal to the leader. Spacer integration proceeds through a two-step transesterification reaction where the 3′ hydroxyl groups of the spacer target both repeat borders on opposite strands. The leader-proximal end of the repeat is preferentially targeted for the first site of integration through recognition of sequences spanning the leader-repeat junction. Subsequently, second-site integration at the leader-distal end of the repeat is specified by multiple determinants including a length-defining mechanism relying on a repeat element proximal to the second site of integration. Our results highlight the intrinsic ability of type II Cas1/Cas2 proteins to coordinate directional and site-specific spacer integration into the CRISPR locus to ensure precise duplication of the repeat required for CRISPR immunity.
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Affiliation(s)
- Jenny G Kim
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Sandra Garrett
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Yunzhou Wei
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Brenton R Graveley
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Michael P Terns
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.,Department of Microbiology, University of Georgia, Athens, GA 30602, USA.,Department of Genetics, University of Georgia, Athens, GA 30602, USA
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27
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Radovcic M, Killelea T, Savitskaya E, Wettstein L, Bolt EL, Ivancic-Bace I. CRISPR-Cas adaptation in Escherichia coli requires RecBCD helicase but not nuclease activity, is independent of homologous recombination, and is antagonized by 5' ssDNA exonucleases. Nucleic Acids Res 2019; 46:10173-10183. [PMID: 30189098 PMCID: PMC6212769 DOI: 10.1093/nar/gky799] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 08/25/2018] [Indexed: 12/29/2022] Open
Abstract
Prokaryotic adaptive immunity is established against mobile genetic elements (MGEs) by ‘naïve adaptation’ when DNA fragments from a newly encountered MGE are integrated into CRISPR–Cas systems. In Escherichia coli, DNA integration catalyzed by Cas1–Cas2 integrase is well understood in mechanistic and structural detail but much less is known about events prior to integration that generate DNA for capture by Cas1–Cas2. Naïve adaptation in E. coli is thought to depend on the DNA helicase-nuclease RecBCD for generating DNA fragments for capture by Cas1–Cas2. The genetics presented here show that naïve adaptation does not require RecBCD nuclease activity but that helicase activity may be important. RecA loading by RecBCD inhibits adaptation explaining previously observed adaptation phenotypes that implicated RecBCD nuclease activity. Genetic analysis of other E. coli nucleases and naïve adaptation revealed that 5′ ssDNA tailed DNA molecules promote new spacer acquisition. We show that purified E. coli Cas1–Cas2 complex binds to and nicks 5′ ssDNA tailed duplexes and propose that E. coli Cas1–Cas2 nuclease activity on such DNA structures supports naïve adaptation.
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Affiliation(s)
- Marin Radovcic
- Department of Biology, Faculty of Science, University of Zagreb, Croatia
| | - Tom Killelea
- School of Life Sciences, University of Nottingham, UK
| | - Ekaterina Savitskaya
- Center for Life Sciences, Skolkovo Institute of Science and Technology, Moscow 143028, Russia.,Institute of Molecular Genetics, Russian Academy of Sciences, Moscow 123182, Russia
| | | | - Edward L Bolt
- School of Life Sciences, University of Nottingham, UK
| | - Ivana Ivancic-Bace
- Department of Biology, Faculty of Science, University of Zagreb, Croatia
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28
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Adaptation processes that build CRISPR immunity: creative destruction, updated. Essays Biochem 2019; 63:227-235. [PMID: 31186288 DOI: 10.1042/ebc20180073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/13/2019] [Accepted: 05/14/2019] [Indexed: 01/01/2023]
Abstract
Prokaryotes can defend themselves against invading mobile genetic elements (MGEs) by acquiring immune memory against them. The memory is a DNA database located at specific chromosomal sites called CRISPRs (clustered regularly interspaced short palindromic repeats) that store fragments of MGE DNA. These are utilised to target and destroy returning MGEs, preventing re-infection. The effectiveness of CRISPR-based immune defence depends on 'adaptation' reactions that capture and integrate MGE DNA fragments into CRISPRs. This provides the means for immunity to be delivered against MGEs in 'interference' reactions. Adaptation and interference are catalysed by Cas (CRISPR-associated) proteins, aided by enzymes well known for other roles in cells. We survey the molecular biology of CRISPR adaptation, highlighting entirely new developments that may help us to understand how MGE DNA is captured. We focus on processes in Escherichia coli, punctuated with reference to other prokaryotes that illustrate how common requirements for adaptation, DNA capture and integration, can be achieved in different ways. We also comment on how CRISPR adaptation enzymes, and their antecedents, can be utilised for biotechnology.
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29
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Plateau P, Moch C, Blanquet S. Spermidine strongly increases the fidelity of Escherichia coli CRISPR Cas1-Cas2 integrase. J Biol Chem 2019; 294:11311-11322. [PMID: 31171718 DOI: 10.1074/jbc.ra119.007619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/03/2019] [Indexed: 12/20/2022] Open
Abstract
Site-selective CRISPR array expansion at the origin of bacterial adaptive immunity relies on recognition of sequence-dependent DNA structures by the conserved Cas1-Cas2 integrase. Off-target integration of a new spacer sequence outside canonical CRISPR arrays has been described in vitro However, this nonspecific integration activity is rare in vivo Here, we designed gel assays to monitor fluorescently labeled protospacer insertion in a supercoiled 3-kb plasmid harboring a minimal CRISPR locus derived from the Escherichia coli type I-E system. This assay enabled us to distinguish and quantify target and off-target insertion events catalyzed by E. coli Cas1-Cas2 integrase. We show that addition of the ubiquitous polyamine spermidine or of another polyamine, spermine, significantly alters the ratio between target and off-target insertions. Notably, addition of 2 mm spermidine quenched the off-target spacer insertion rate by a factor of 20-fold, and, in the presence of integration host factor, spermidine also increased insertion at the CRISPR locus 1.5-fold. The observation made in our in vitro system that spermidine strongly decreases nonspecific activity of Cas1-Cas2 integrase outside the leader-proximal region of a CRISPR array suggests that this polyamine plays a potential role in the fidelity of the spacer integration also in vivo.
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Affiliation(s)
- Pierre Plateau
- BIOC, CNRS, Ecole polytechnique, IP Paris, F-91128 Palaiseau, France
| | - Clara Moch
- BIOC, CNRS, Ecole polytechnique, IP Paris, F-91128 Palaiseau, France
| | - Sylvain Blanquet
- BIOC, CNRS, Ecole polytechnique, IP Paris, F-91128 Palaiseau, France
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30
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Hou S, Brenes-Álvarez M, Reimann V, Alkhnbashi OS, Backofen R, Muro-Pastor AM, Hess WR. CRISPR-Cas systems in multicellular cyanobacteria. RNA Biol 2019; 16:518-529. [PMID: 29995583 PMCID: PMC6546389 DOI: 10.1080/15476286.2018.1493330] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 07/01/2018] [Accepted: 06/19/2018] [Indexed: 01/12/2023] Open
Abstract
Novel CRISPR-Cas systems possess substantial potential for genome editing and manipulation of gene expression. The types and numbers of CRISPR-Cas systems vary substantially between different organisms. Some filamentous cyanobacteria harbor > 40 different putative CRISPR repeat-spacer cassettes, while the number of cas gene instances is much lower. Here we addressed the types and diversity of CRISPR-Cas systems and of CRISPR-like repeat-spacer arrays in 171 publicly available genomes of multicellular cyanobacteria. The number of 1328 repeat-spacer arrays exceeded the total of 391 encoded Cas1 proteins suggesting a tendency for fragmentation or the involvement of alternative adaptation factors. The model cyanobacterium Anabaena sp. PCC 7120 contains only three cas1 genes but hosts three Class 1, possibly one Class 2 and five orphan repeat-spacer arrays, all of which exhibit crRNA-typical expression patterns suggesting active transcription, maturation and incorporation into CRISPR complexes. The CRISPR-Cas system within the element interrupting the Anabaena sp. PCC 7120 fdxN gene, as well as analogous arrangements in other strains, occupy the genetic elements that become excised during the differentiation-related programmed site-specific recombination. This fact indicates the propensity of these elements for the integration of CRISPR-cas systems and points to a previously not recognized connection. The gene all3613 resembling a possible Class 2 effector protein is linked to a short repeat-spacer array and a single tRNA gene, similar to its homologs in other cyanobacteria. The diversity and presence of numerous CRISPR-Cas systems in DNA elements that are programmed for homologous recombination make filamentous cyanobacteria a prolific resource for their study. Abbreviations: Cas: CRISPR associated sequences; CRISPR: Clustered Regularly Interspaced Short Palindromic Repeats; C2c: Class 2 candidate; SDR: small dispersed repeat; TSS: transcriptional start site; UTR: untranslated region.
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Affiliation(s)
- Shengwei Hou
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Freiburg, Germany
| | - Manuel Brenes-Álvarez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Seville, Spain
| | - Viktoria Reimann
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Freiburg, Germany
| | - Omer S. Alkhnbashi
- Bioinformatics group, Department of Computer Science, University of Freiburg, Freiburg, Germany
| | - Rolf Backofen
- Bioinformatics group, Department of Computer Science, University of Freiburg, Freiburg, Germany
- Center for Biological Systems Analysis (ZBSA), University of Freiburg, Freiburg, Germany
- BIOSS Centre for Biological Signaling Studies, University of Freiburg, Freiburg, Germany
| | - Alicia M. Muro-Pastor
- Bioinformatics group, Department of Computer Science, University of Freiburg, Freiburg, Germany
| | - Wolfgang R. Hess
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Freiburg, Germany
- Freiburg Institute for Advanced Studies,University of Freiburg, Freiburg, Germany
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31
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Wright AV, Wang JY, Burstein D, Harrington LB, Paez-Espino D, Kyrpides NC, Iavarone AT, Banfield JF, Doudna JA. A Functional Mini-Integrase in a Two-Protein-type V-C CRISPR System. Mol Cell 2019; 73:727-737.e3. [PMID: 30709710 PMCID: PMC6386590 DOI: 10.1016/j.molcel.2018.12.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/21/2018] [Accepted: 12/14/2018] [Indexed: 12/26/2022]
Abstract
CRISPR-Cas immunity requires integration of short, foreign DNA fragments into the host genome at the CRISPR locus, a site consisting of alternating repeat sequences and foreign-derived spacers. In most CRISPR systems, the proteins Cas1 and Cas2 form the integration complex and are both essential for DNA acquisition. Most type V-C and V-D systems lack the cas2 gene and have unusually short CRISPR repeats and spacers. Here, we show that a mini-integrase comprising the type V-C Cas1 protein alone catalyzes DNA integration with a preference for short (17- to 19-base-pair) DNA fragments. The mini-integrase has weak specificity for the CRISPR array. We present evidence that the Cas1 proteins form a tetramer for integration. Our findings support a model of a minimal integrase with an internal ruler mechanism that favors shorter repeats and spacers. This minimal integrase may represent the function of the ancestral Cas1 prior to Cas2 adoption.
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Affiliation(s)
- Addison V Wright
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Joy Y Wang
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - David Burstein
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA 94720, USA
| | - Lucas B Harrington
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - David Paez-Espino
- Department of Energy, Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Nikos C Kyrpides
- Department of Energy, Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Anthony T Iavarone
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA; California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA 94720, USA
| | - Jillian F Banfield
- Department of Earth and Planetary Sciences, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA 94720, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Jennifer A Doudna
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA; MBIB Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Gladstone Institutes, San Francisco, CA 94158, USA.
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32
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Xue C, Sashital DG. Mechanisms of Type I-E and I-F CRISPR-Cas Systems in Enterobacteriaceae. EcoSal Plus 2019; 8:10.1128/ecosalplus.ESP-0008-2018. [PMID: 30724156 PMCID: PMC6368399 DOI: 10.1128/ecosalplus.esp-0008-2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Indexed: 12/17/2022]
Abstract
CRISPR-Cas systems provide bacteria and archaea with adaptive immunity against invasion by bacteriophages and other mobile genetic elements. Short fragments of invader DNA are stored as immunological memories within CRISPR (clustered regularly interspaced short palindromic repeat) arrays in the host chromosome. These arrays provide a template for RNA molecules that can guide CRISPR-associated (Cas) proteins to specifically neutralize viruses upon subsequent infection. Over the past 10 years, our understanding of CRISPR-Cas systems has benefited greatly from a number of model organisms. In particular, the study of several members of the Gram-negative Enterobacteriaceae family, especially Escherichia coli and Pectobacterium atrosepticum, have provided significant insights into the mechanisms of CRISPR-Cas immunity. In this review, we provide an overview of CRISPR-Cas systems present in members of the Enterobacteriaceae. We also detail the current mechanistic understanding of the type I-E and type I-F CRISPR-Cas systems that are commonly found in enterobacteria. Finally, we discuss how phages can escape or inactivate CRISPR-Cas systems and the measures bacteria can enact to counter these types of events.
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Affiliation(s)
- Chaoyou Xue
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA
- Present address: Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY
| | - Dipali G Sashital
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA
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33
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Fagerlund RD, Ferguson TJ, Maxwell HW, Opel-Reading HK, Krause KL, Fineran PC. Reconstitution of CRISPR adaptation in vitro and its detection by PCR. Methods Enzymol 2019; 616:411-433. [DOI: 10.1016/bs.mie.2018.10.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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34
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Medina-Aparicio L, Dávila S, Rebollar-Flores JE, Calva E, Hernández-Lucas I. The CRISPR-Cas system in Enterobacteriaceae. Pathog Dis 2018; 76:4794941. [PMID: 29325038 DOI: 10.1093/femspd/fty002] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/08/2018] [Indexed: 12/20/2022] Open
Abstract
In nature, microorganisms are constantly exposed to multiple viral infections and thus have developed many strategies to survive phage attack and invasion by foreign DNA. One of such strategies is the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) bacterial immunological system. This defense mechanism is widespread in prokaryotes including several families such as Enterobacteriaceae. Much knowledge about the CRISPR-Cas system has been generated, including its biological functions, transcriptional regulation, distribution, utility as a molecular marker and as a tool for specific genome editing. This review focuses on these aspects and describes the state of the art of the CRISPR-Cas system in the Enterobacteriaceae bacterial family.
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Affiliation(s)
- Liliana Medina-Aparicio
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos 62210, México
| | - Sonia Dávila
- Centro de Investigación en Dinámica Celular, Universidad Autónoma del Estado de Morelos, Av. Universidad No. 1001, Cuernavaca, Morelos 62209, México
| | - Javier E Rebollar-Flores
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos 62210, México
| | - Edmundo Calva
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos 62210, México
| | - Ismael Hernández-Lucas
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos 62210, México
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35
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He Y, Wang M, Liu M, Huang L, Liu C, Zhang X, Yi H, Cheng A, Zhu D, Yang Q, Wu Y, Zhao X, Chen S, Jia R, Zhang S, Liu Y, Yu Y, Zhang L. Cas1 and Cas2 From the Type II-C CRISPR-Cas System of Riemerella anatipestifer Are Required for Spacer Acquisition. Front Cell Infect Microbiol 2018; 8:195. [PMID: 29951376 PMCID: PMC6008519 DOI: 10.3389/fcimb.2018.00195] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 05/24/2018] [Indexed: 12/22/2022] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins provide acquired genetic immunity against the entry of mobile genetic elements (MGEs). The immune defense provided by various subtypes of the CRISPR-Cas system has been confirmed and is closely associated with the formation of immunological memory in CRISPR arrays, called CRISPR adaptation or spacer acquisition. However, whether type II-C CRISPR-Cas systems are also involved in spacer acquisition remains largely unknown. This study explores and provides some definitive evidence regarding spacer acquisition of the type II-C CRISPR-Cas system from Riemerella anatipestifer (RA) CH-2 (RA-CH-2). Firstly, introducing an exogenous plasmid into RA-CH-2 triggered spacer acquisition of RA CRISPR-Cas system, and the acquisition of new spacers led to plasmid instability in RA-CH-2. Furthermore, deletion of cas1 or cas2 of RA-CH-2 abrogated spacer acquisition and subsequently stabilized the exogenous plasmid, suggesting that both Cas1 and Cas2 are required for spacer acquisition of RA-CH-2 CRISPR-Cas system, consistent with the reported role of Cas1 and Cas2 in type I-E and II-A systems. Finally, assays for studying Cas1 nuclease activity and the interaction of Cas1 with Cas2 contributed to a better understanding of the adaptation mechanism of RA CRISPR-Cas system. This is the first experimental identification of the naïve adaptation of type II-C CRISPR-Cas system.
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Affiliation(s)
- Yang He
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Li Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Chaoyue Liu
- Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Department of Microbiology and Immunology, North Sichuan Medical College, Nanchong, China
| | - Xin Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Haibo Yi
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Dekang Zhu
- Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xinxin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yunya Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yanling Yu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ling Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, China.,Avian Diseases Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
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36
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Hille F, Richter H, Wong SP, Bratovič M, Ressel S, Charpentier E. The Biology of CRISPR-Cas: Backward and Forward. Cell 2018. [DOI: 10.1016/j.cell.2017.11.032] [Citation(s) in RCA: 333] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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37
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Rollie C, Graham S, Rouillon C, White MF. Prespacer processing and specific integration in a Type I-A CRISPR system. Nucleic Acids Res 2018; 46:1007-1020. [PMID: 29228332 PMCID: PMC5815122 DOI: 10.1093/nar/gkx1232] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/22/2017] [Accepted: 11/29/2017] [Indexed: 12/15/2022] Open
Abstract
The CRISPR-Cas system for prokaryotic adaptive immunity provides RNA-mediated protection from viruses and mobile genetic elements. Adaptation is dependent on the Cas1 and Cas2 proteins along with varying accessory proteins. Here we analyse the process in Sulfolobus solfataricus, showing that while Cas1 and Cas2 catalyze spacer integration in vitro, host factors are required for specificity. Specific integration also requires at least 400 bp of the leader sequence, and is dependent on the presence of hydrolysable ATP, suggestive of an active process that may involve DNA remodelling. Specific spacer integration is associated with processing of prespacer 3' ends in a PAM-dependent manner. This is reflected in PAM-dependent processing of prespacer 3' ends in vitro in the presence of cell lysate or the Cas4 nuclease, in a reaction consistent with PAM-directed binding and protection of prespacer DNA. These results highlight the diverse interplay between CRISPR-Cas elements and host proteins across CRISPR types.
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Affiliation(s)
- Clare Rollie
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK
| | - Shirley Graham
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK
| | - Christophe Rouillon
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK
| | - Malcolm F White
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK
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38
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Abstract
Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein (CRISPR-Cas) systems store the memory of past encounters with foreign DNA in unique spacers that are inserted between direct repeats in CRISPR arrays. For only a small fraction of the spacers, homologous sequences, called protospacers, are detectable in viral, plasmid, and microbial genomes. The rest of the spacers remain the CRISPR “dark matter.” We performed a comprehensive analysis of the spacers from all CRISPR-cas loci identified in bacterial and archaeal genomes, and we found that, depending on the CRISPR-Cas subtype and the prokaryotic phylum, protospacers were detectable for 1% to about 19% of the spacers (~7% global average). Among the detected protospacers, the majority, typically 80 to 90%, originated from viral genomes, including proviruses, and among the rest, the most common source was genes that are integrated into microbial chromosomes but are involved in plasmid conjugation or replication. Thus, almost all spacers with identifiable protospacers target mobile genetic elements (MGE). The GC content, as well as dinucleotide and tetranucleotide compositions, of microbial genomes, their spacer complements, and the cognate viral genomes showed a nearly perfect correlation and were almost identical. Given the near absence of self-targeting spacers, these findings are most compatible with the possibility that the spacers, including the dark matter, are derived almost completely from the species-specific microbial mobilomes. The principal function of CRISPR-Cas systems is thought to be protection of bacteria and archaea against viruses and other parasitic genetic elements. The CRISPR defense function is mediated by sequences from parasitic elements, known as spacers, that are inserted into CRISPR arrays and then transcribed and employed as guides to identify and inactivate the cognate parasitic genomes. However, only a small fraction of the CRISPR spacers match any sequences in the current databases, and of these, only a minority correspond to known parasitic elements. We show that nearly all spacers with matches originate from viral or plasmid genomes that are either free or have been integrated into the host genome. We further demonstrate that spacers with no matches have the same properties as those of identifiable origins, strongly suggesting that all spacers originate from mobile elements.
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39
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How type II CRISPR-Cas establish immunity through Cas1-Cas2-mediated spacer integration. Nature 2017; 550:137-141. [PMID: 28869593 PMCID: PMC5832332 DOI: 10.1038/nature24020] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 08/24/2017] [Indexed: 11/28/2022]
Abstract
CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) and the nearby cas (CRISPR-associated) operon establish an RNA-based adaptive immunity system in prokaryotes1–5. Molecular memory is created when a short foreign DNA-derived prespacer is integrated into the CRISPR array as a new spacer6–9. Whereas the RNA-guided CRISPR interference mechanism varies widely among CRISPR-Cas systems, the spacer integration mechanism is essentially identical7–9. The conserved Cas1 and Cas2 proteins form an integrase complex consisting two distal Cas1 dimers bridged by a Cas2 dimer in the middle6,10. The prespacer is bound by Cas1-Cas2 as a dual forked DNA, and the terminal 3′-OH of each 3′-overhang serves as an attacking nucleophile during integration11–14. Importantly, the prespacer is preferentially integrated into the leader-proximal region of the CRISPR array1,7,10,15, guided by the leader sequence and a pair of inverted repeats (IRs) inside the CRISPR repeat7,15–20. Spacer integration in the most well-studied Escherichia coli Type I-E CRISPR system further relies on the bacterial Integration Host Factor (IHF)21,22. In Type II-A CRISPR, however, Cas1-Cas2 alone integrates spacer efficiently in vitro18; other Cas proteins (Cas9 and Csn2) play accessory roles in prespacer biogenesis17,23. Focusing on the Enterococcus faecalis Type II-A system24, here we report four structure snapshots of Cas1-Cas2 during spacer integration. EfaCas1-Cas2 selectively binds to a splayed 30-bp prespacer bearing 4-nt 3′-overhangs. Three molecular events take place upon encountering a target: Cas1-Cas2/prespacer first searches for half-sites stochastically, then preferentially interacts with the leader-side CRISPR repeat and catalyzes a nucleophilic attack that connects one strand of the leader-proximal repeat to the prespacer 3′-overhang. Recognition of the spacer half-site requires DNA bending and leads to full integration. We derive a mechanistic framework explaining the stepwise spacer integration process and the leader-proximal preference.
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Ka D, Hong S, Jeong U, Jeong M, Suh N, Suh JY, Bae E. Structural and dynamic insights into the role of conformational switching in the nuclease activity of the Xanthomonas albilineans Cas2 in CRISPR-mediated adaptive immunity. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2017; 4:054701. [PMID: 28612041 PMCID: PMC5438308 DOI: 10.1063/1.4984052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 05/11/2017] [Indexed: 06/07/2023]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) proteins constitute a microbial, adaptive immune system countering invading nucleic acids. Cas2 is a universal Cas protein found in all types of CRISPR-Cas systems, and its role is implicated in new spacer acquisition into CRISPR loci. In subtype I-C CRISPR-Cas systems, Cas2 proteins are metal-dependent double-stranded DNA (dsDNA) nucleases, and a pH-dependent conformational transition has been proposed as a prerequisite for catalytic action. Here, we report the crystal structure of Xanthomonas albilineans Cas2 (XaCas2) and provide experimental evidence of a pH-dependent conformational change during functional activation. XaCas2 crystallized at an acidic pH represented a catalytically inactive conformational state in which two Asp8 residues were too far apart to coordinate a single catalytic metal ion. Consistently, XaCas2 exhibited dsDNA nuclease activity only under neutral and basic conditions. Despite the overall structural similarity of the two protomers, significant conformational heterogeneity was evident in the putative hinge regions, suggesting that XaCas2 engages in hinge-bending conformational switching. The presence of a Trp residue in the hinge region enabled the investigation of hinge dynamics by fluorescence spectroscopy. The pH dependence of the fluorescence intensity overlapped precisely with that of nuclease activity. Mutational analyses further suggested that conformational activation proceeded via a rigid-body hinge-bending motion as both D8E and hinge mutations significantly reduced nuclease activity. Together, our results reveal strong correlations between the conformational states, catalytic activity, and hinge dynamics of XaCas2, and provide structural and dynamic insights into the conformational activation of the nuclease function of Cas2.
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Affiliation(s)
- Donghyun Ka
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, South Korea
| | - Suji Hong
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, South Korea
| | - Ugeene Jeong
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, South Korea
| | - Migyeong Jeong
- Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, South Korea
| | - Nayoung Suh
- Department of Pharmaceutical Engineering, Soon Chun Hyang University, Asan 31538, South Korea
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Wright AV, Liu JJ, Knott GJ, Doxzen KW, Nogales E, Doudna JA. Structures of the CRISPR genome integration complex. Science 2017; 357:1113-1118. [PMID: 28729350 DOI: 10.1126/science.aao0679] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 07/13/2017] [Indexed: 12/21/2022]
Abstract
CRISPR-Cas systems depend on the Cas1-Cas2 integrase to capture and integrate short foreign DNA fragments into the CRISPR locus, enabling adaptation to new viruses. We present crystal structures of Cas1-Cas2 bound to both donor and target DNA in intermediate and product integration complexes, as well as a cryo-electron microscopy structure of the full CRISPR locus integration complex, including the accessory protein IHF (integration host factor). The structures show unexpectedly that indirect sequence recognition dictates integration site selection by favoring deformation of the repeat and the flanking sequences. IHF binding bends the DNA sharply, bringing an upstream recognition motif into contact with Cas1 to increase both the specificity and efficiency of integration. These results explain how the Cas1-Cas2 CRISPR integrase recognizes a sequence-dependent DNA structure to ensure site-selective CRISPR array expansion during the initial step of bacterial adaptive immunity.
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Affiliation(s)
- Addison V Wright
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Jun-Jie Liu
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Gavin J Knott
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Kevin W Doxzen
- Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Eva Nogales
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.,Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Jennifer A Doudna
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA. .,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.,Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA 94720, USA.,Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA.,Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA.,Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA.,Center for RNA Systems Biology, University of California, Berkeley, Berkeley, CA 94720, USA
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Krupovic M, Béguin P, Koonin EV. Casposons: mobile genetic elements that gave rise to the CRISPR-Cas adaptation machinery. Curr Opin Microbiol 2017; 38:36-43. [PMID: 28472712 DOI: 10.1016/j.mib.2017.04.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 04/04/2017] [Accepted: 04/12/2017] [Indexed: 01/26/2023]
Abstract
A casposon, a member of a distinct superfamily of archaeal and bacterial self-synthesizing transposons that employ a recombinase (casposase) homologous to the Cas1 endonuclease, appears to have given rise to the adaptation module of CRISPR-Cas systems as well as the CRISPR repeats themselves. Comparison of the mechanistic features of the reactions catalyzed by the casposase and the Cas1-Cas2 heterohexamer, the CRISPR integrase, reveals close similarity but also important differences that explain the requirement of Cas2 for integration of short DNA fragments, the CRISPR spacers.
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Affiliation(s)
- Mart Krupovic
- Unité Biologie Moléculaire du Gène chez les Extrêmophiles, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France.
| | - Pierre Béguin
- Unité Biologie Moléculaire du Gène chez les Extrêmophiles, Institut Pasteur, 25 rue du Docteur Roux, 75015 Paris, France
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA
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Jackson SA, McKenzie RE, Fagerlund RD, Kieper SN, Fineran PC, Brouns SJJ. CRISPR-Cas: Adapting to change. Science 2017; 356:356/6333/eaal5056. [PMID: 28385959 DOI: 10.1126/science.aal5056] [Citation(s) in RCA: 249] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Bacteria and archaea are engaged in a constant arms race to defend against the ever-present threats of viruses and invasion by mobile genetic elements. The most flexible weapons in the prokaryotic defense arsenal are the CRISPR-Cas adaptive immune systems. These systems are capable of selective identification and neutralization of foreign DNA and/or RNA. CRISPR-Cas systems rely on stored genetic memories to facilitate target recognition. Thus, to keep pace with a changing pool of hostile invaders, the CRISPR memory banks must be regularly updated with new information through a process termed CRISPR adaptation. In this Review, we outline the recent advances in our understanding of the molecular mechanisms governing CRISPR adaptation. Specifically, the conserved protein machinery Cas1-Cas2 is the cornerstone of adaptive immunity in a range of diverse CRISPR-Cas systems.
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Affiliation(s)
- Simon A Jackson
- Department of Microbiology and Immunology, University of Otago, Post Office Box 56, Dunedin 9054, New Zealand
| | - Rebecca E McKenzie
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, Netherlands
| | - Robert D Fagerlund
- Department of Microbiology and Immunology, University of Otago, Post Office Box 56, Dunedin 9054, New Zealand
| | - Sebastian N Kieper
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, Netherlands
| | - Peter C Fineran
- Department of Microbiology and Immunology, University of Otago, Post Office Box 56, Dunedin 9054, New Zealand. .,Bio-Protection Research Centre, University of Otago, Post Office Box 56, Dunedin 9054, New Zealand
| | - Stan J J Brouns
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, Netherlands. .,Laboratory of Microbiology, Wageningen University, Wageningen, Netherlands
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