1
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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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2
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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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3
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Dong Y, Chen YM, Kong XJ, Gao SQ, Lang JJ, Du KJ, Lin YW. Rational design of an artificial hydrolytic nuclease by introduction of a sodium copper chlorophyllin in L29E myoglobin. J Inorg Biochem 2022; 235:111943. [PMID: 35907294 DOI: 10.1016/j.jinorgbio.2022.111943] [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: 06/21/2022] [Revised: 07/12/2022] [Accepted: 07/20/2022] [Indexed: 11/26/2022]
Abstract
Heme proteins have recently emerged as promising artificial metalloenzymes for catalyzing diverse reactions. In this report, L29E Mb, a single mutant of myoglobin (Mb), was reconstituted by replacing the heme with a sodium copper cholorophyllin (CuCP) to form a new green artificial enzyme (named CuCP-L29E Mb). The reconstituted protein CuCP-L29E Mb was found to exhibit hydrolytic DNA cleavage activity, which was not depending on O2. In addition, Mg2+ ion could effectively promote the DNA cleavage activity of CuCP-L29E Mb. Wild-type (WT) Mb reconstituted with CuCP (named CuCP-WT Mb) did not show DNA cleavage activity under the same conditions. This study suggests that both Mg2+ and the ligand Glu29 are critical for the nuclease activity and the artificial nuclease of Mg2+-CuCP-L29E Mb may have potential applications in the future.
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Affiliation(s)
- Yao Dong
- School of Chemistry and Chemical Engineering, Laboratory of Protein Structure and Function, Hunan Key Laboratory for the Design and Application of Actinide Complexes, University of South China, Hengyang 421001, China
| | - Yu-Mei Chen
- School of Chemistry and Chemical Engineering, Laboratory of Protein Structure and Function, Hunan Key Laboratory for the Design and Application of Actinide Complexes, University of South China, Hengyang 421001, China
| | - Xiang-Jun Kong
- School of Chemistry and Chemical Engineering, Laboratory of Protein Structure and Function, Hunan Key Laboratory for the Design and Application of Actinide Complexes, University of South China, Hengyang 421001, China
| | - Shu-Qin Gao
- School of Chemistry and Chemical Engineering, Laboratory of Protein Structure and Function, Hunan Key Laboratory for the Design and Application of Actinide Complexes, University of South China, Hengyang 421001, China
| | - Jia-Jia Lang
- School of Chemistry and Chemical Engineering, Laboratory of Protein Structure and Function, Hunan Key Laboratory for the Design and Application of Actinide Complexes, University of South China, Hengyang 421001, China
| | - Ke-Jie Du
- School of Chemistry and Chemical Engineering, Laboratory of Protein Structure and Function, Hunan Key Laboratory for the Design and Application of Actinide Complexes, University of South China, Hengyang 421001, China.
| | - Ying-Wu Lin
- School of Chemistry and Chemical Engineering, Laboratory of Protein Structure and Function, Hunan Key Laboratory for the Design and Application of Actinide Complexes, University of South China, Hengyang 421001, China.
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4
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Zhang C, Xue T, Zhang J, Li Z, Liu L, Xie J, Yao J, Wang G, Ye X, Zhu W. Terahertz meta-biosensor based on high-Q electrical resonance enhanced by the interference of toroidal dipole. Biosens Bioelectron 2022; 214:114493. [PMID: 35780535 DOI: 10.1016/j.bios.2022.114493] [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: 03/19/2022] [Revised: 06/15/2022] [Accepted: 06/17/2022] [Indexed: 11/02/2022]
Abstract
Electrical dipole resonances typically have low Q factor and broad resonant linewidth caused by strong free-space coupling with high radiative loss. Here, we present a strategy for enhancing the Q factor of the electrical resonance via the interference of a toroidal dipole. To validate such a strategy, a metasurface consisting of two resonators is designed that responsible to the electric and toroidal dipoles. According to constructive and destructive hybridizations of the two dipole modes, enhanced and decreased Q factors are found respectively for the two hybrid modes, compared to the one for the conventional electric dipole resonance. As a practical application of such high Q resonance, we further experimentally investigate the sensing performance of the metasurface biosensor by detecting the cell concentration of lung cancer cells (type A549). Moreover, through monitoring both resonance frequency and amplitude variation of the metasurface biosensor, the dielectric permittivity of the lung cancer cells is delicately estimated by the conjoint analysis of both simulated and measured results. Our proposed metasurface paves a promising way for the study of multipole interference in the field of nanophotonics and validates its effectiveness in biomedical sensing.
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Affiliation(s)
- Chiben Zhang
- Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; Air and Missile Defense College, Air Force Engineering University, 710051, Xi'an, China
| | - Tingjia Xue
- Department of Radiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Jin Zhang
- Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhenfei Li
- Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Longhai Liu
- Advantest (China) Co., Ltd. Shanghai, 201203, China; College of Precision Instruments and Opto-Electronics Engineering, Institute of Laser and Optoelectronics, Tianjin University, Tianjin, 300072, China
| | - Jianhua Xie
- Advantest (China) Co., Ltd. Shanghai, 201203, China
| | - Jianquan Yao
- College of Precision Instruments and Opto-Electronics Engineering, Institute of Laser and Optoelectronics, Tianjin University, Tianjin, 300072, China
| | - Guangming Wang
- Air and Missile Defense College, Air Force Engineering University, 710051, Xi'an, China.
| | - Xiaodan Ye
- Department of Radiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, 200030, China; Department of Radiology, Shanghai Institute of Medical Imaging, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.
| | - Weiren Zhu
- Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
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5
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Lénon M, Arias-Cartín R, Barras F. The Fe-S proteome of Escherichia coli: prediction, function and fate. Metallomics 2022; 14:6555457. [PMID: 35349713 DOI: 10.1093/mtomcs/mfac022] [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: 02/01/2022] [Accepted: 03/14/2022] [Indexed: 11/13/2022]
Abstract
Iron-sulfur (Fe-S) clusters are inorganic ubiquitous and ancient cofactors. Fe-S bound proteins contribute to most cellular processes, including DNA replication and integrity, genetic expression and regulation, metabolism, biosynthesis and most bioenergetics systems. Also, Fe-S proteins hold a great biotechnological potential in metabolite and chemical production, including antibiotics. From classic biophysics and spectroscopy methodologies to recent development in bioinformatics, including structural modeling and chemoproteomics, our capacity to predict and identify Fe-S proteins has spectacularly increased over the recent years. Here, these developments are presented and collectively used to update the composition of Escherichia coli Fe-S proteome, for which we predict 181 occurrences, i.e. 40 more candidates than in our last catalog (Py and Barras, 2010), and equivalent to 4% of its total proteome. Besides, Fe-S clusters can be targeted by redox active compounds or reactive oxygen and nitrosative species, and even be destabilized by contaminant metals. Accordingly, we discuss how cells handle damaged Fe-S proteins, i.e. degradation, recycling or repair.
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Affiliation(s)
- Marine Lénon
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Stress Adaptation and Metabolism Unit, Department of Microbiology, F-75015 Paris, France
| | - Rodrigo Arias-Cartín
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Stress Adaptation and Metabolism Unit, Department of Microbiology, F-75015 Paris, France
| | - Frédéric Barras
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Stress Adaptation and Metabolism Unit, Department of Microbiology, F-75015 Paris, France
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6
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Kim NH, Choi H, Shahzad ZM, Ki H, Lee J, Chae H, Kim YH. Supramolecular assembly of protein building blocks: from folding to function. NANO CONVERGENCE 2022; 9:4. [PMID: 35024976 PMCID: PMC8755899 DOI: 10.1186/s40580-021-00294-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Several phenomena occurring throughout the life of living things start and end with proteins. Various proteins form one complex structure to control detailed reactions. In contrast, one protein forms various structures and implements other biological phenomena depending on the situation. The basic principle that forms these hierarchical structures is protein self-assembly. A single building block is sufficient to create homogeneous structures with complex shapes, such as rings, filaments, or containers. These assemblies are widely used in biology as they enable multivalent binding, ultra-sensitive regulation, and compartmentalization. Moreover, with advances in the computational design of protein folding and protein-protein interfaces, considerable progress has recently been made in the de novo design of protein assemblies. Our review presents a description of the components of supramolecular protein assembly and their application in understanding biological phenomena to therapeutics.
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Affiliation(s)
- Nam Hyeong Kim
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Hojae Choi
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Zafar Muhammad Shahzad
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- School of Chemical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Heesoo Ki
- Department of Nano Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Jaekyoung Lee
- Department of Nano Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Heeyeop Chae
- School of Chemical Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Yong Ho Kim
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Republic of Korea.
- Department of Nano Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea.
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7
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Dixit B, Anand V, Hussain MS, Kumar M. The CRISPR-associated Cas4 protein from Leptospira interrogans demonstrate versatile nuclease activity. CURRENT RESEARCH IN MICROBIAL SCIENCES 2021; 2:100040. [PMID: 34841331 PMCID: PMC8610317 DOI: 10.1016/j.crmicr.2021.100040] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/27/2021] [Accepted: 05/27/2021] [Indexed: 12/18/2022] Open
Abstract
The Cas4 protein is one of the core CRISPR-associated (Cas) proteins implicated in the adaptation module in many variants of the CRISPR-Cas system in prokaryotes against the invading genetic elements. Cas4 is recognized as a DNA exonuclease that contains a RecB nuclease domain and a Fe-S cluster-binding module. In Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130, the cas4 gene is functionally transcribed as an active component of the CRISPR-Cas I-B system. Investigation of nuclease activity of Cas4 (LinCas4) of the L. interrogans illustrated divalent-metal cofactor (Mn2+ or Mg2+) dependent endonuclease activity on the DNA substrate. In agreement, mutation of the selective metal interacting residues (Asp74 and Glu87) curtails the DNA cleavage activity in LinCas4. Computational modeling shows metal-ion interacting residues (Asp74 and Glu87) in the LinCas4 to be a part of the RecB motifs II and III, the same as other Cas4 orthologs. The mutation of a potential DNA interacting residue in the LinCas4 (LinCas4Y132A) or one of the four cysteine residues (LinCas4C18A) involved in coordinating the 4Fe-4S cluster did not perturb its DNase activity. Iron chelation assay of the purified LinCas4 demonstrated it in the apostate conformation. Reconstitution of the Fe-S cluster in the LinCas4 under in vitro condition displayed its coordination with four iron atoms per LinCas4 monomer and was confirmed by the UV and CD spectroscopy studies.
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Affiliation(s)
- Bhuvan Dixit
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Vineet Anand
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Md. Saddam Hussain
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Manish Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
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8
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Mechanism for Cas4-assisted directional spacer acquisition in CRISPR-Cas. Nature 2021; 598:515-520. [PMID: 34588691 PMCID: PMC9164213 DOI: 10.1038/s41586-021-03951-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 08/25/2021] [Indexed: 02/08/2023]
Abstract
Prokaryotes adapt to challenges from mobile genetic elements by integrating spacers derived from foreign DNA in the CRISPR array1. Spacer insertion is carried out by the Cas1-Cas2 integrase complex2-4. A substantial fraction of CRISPR-Cas systems use a Fe-S cluster containing Cas4 nuclease to ensure that spacers are acquired from DNA flanked by a protospacer adjacent motif (PAM)5,6 and inserted into the CRISPR array unidirectionally, so that the transcribed CRISPR RNA can guide target searching in a PAM-dependent manner. Here we provide a high-resolution mechanistic explanation for the Cas4-assisted PAM selection, spacer biogenesis and directional integration by type I-G CRISPR in Geobacter sulfurreducens, in which Cas4 is naturally fused with Cas1, forming Cas4/Cas1. During biogenesis, only DNA duplexes possessing a PAM-embedded 3'-overhang trigger Cas4/Cas1-Cas2 assembly. During this process, the PAM overhang is specifically recognized and sequestered, but is not cleaved by Cas4. This 'molecular constipation' prevents the PAM-side prespacer from participating in integration. Lacking such sequestration, the non-PAM overhang is trimmed by host nucleases and integrated to the leader-side CRISPR repeat. Half-integration subsequently triggers PAM cleavage and Cas4 dissociation, allowing spacer-side integration. Overall, the intricate molecular interaction between Cas4 and Cas1-Cas2 selects PAM-containing prespacers for integration and couples the timing of PAM processing with the stepwise integration to establish directionality.
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9
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Kieper SN, Almendros C, Haagsma AC, Barendregt A, Heck AJR, Brouns SJJ. Cas4-Cas1 Is a Protospacer Adjacent Motif-Processing Factor Mediating Half-Site Spacer Integration During CRISPR Adaptation. CRISPR J 2021; 4:536-548. [PMID: 34406043 DOI: 10.1089/crispr.2021.0011] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The immunization of bacteria and archaea against invading viruses via CRISPR adaptation is critically reliant on the efficient capture, accurate processing, and integration of CRISPR spacers into the host genome. The adaptation proteins Cas1 and Cas2 are sufficient for successful spacer acquisition in some CRISPR-Cas systems. However, many CRISPR-Cas systems additionally require the Cas4 protein for efficient adaptation. Cas4 has been implied in the selection and processing of spacer precursors, but the detailed mechanistic understanding of how Cas4 contributes to CRISPR adaptation is lacking. Here, we biochemically reconstitute the CRISPR-Cas type I-D adaptation system and show two functionally distinct adaptation complexes: Cas4-Cas1 and Cas1-Cas2. The Cas4-Cas1 complex recognizes and cleaves protospacer adjacent motif (PAM) sequences in 3' overhangs in a sequence-specific manner, while the Cas1-Cas2 complex defines the cleavage of non-PAM sites via host-factor nucleases. Both sub-complexes are capable of mediating half-site integration, facilitating the integration of processed spacers in the correct interference-proficient orientation. We provide a model in which an asymmetric adaptation complex differentially acts on PAM- and non-PAM-containing overhangs, providing cues for the correct orientation of spacer integration.
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Affiliation(s)
- Sebastian N Kieper
- Department of Bionanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands
| | - Cristóbal Almendros
- Department of Bionanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands
| | - Anna C Haagsma
- Department of Bionanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands
| | - Arjan Barendregt
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Utrecht, Netherlands; and Utrecht, Netherlands.,Netherlands Proteomics Center, Utrecht, Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Utrecht, Netherlands; and Utrecht, Netherlands.,Netherlands Proteomics Center, Utrecht, Netherlands
| | - Stan J J Brouns
- Department of Bionanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands
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10
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Hambarde S, Tsai CL, Pandita RK, Bacolla A, Maitra A, Charaka V, Hunt CR, Kumar R, Limbo O, Le Meur R, Chazin WJ, Tsutakawa SE, Russell P, Schlacher K, Pandita TK, Tainer JA. EXO5-DNA structure and BLM interactions direct DNA resection critical for ATR-dependent replication restart. Mol Cell 2021; 81:2989-3006.e9. [PMID: 34197737 PMCID: PMC8720176 DOI: 10.1016/j.molcel.2021.05.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 04/09/2021] [Accepted: 05/24/2021] [Indexed: 02/07/2023]
Abstract
Stalled DNA replication fork restart after stress as orchestrated by ATR kinase, BLM helicase, and structure-specific nucleases enables replication, cell survival, and genome stability. Here we unveil human exonuclease V (EXO5) as an ATR-regulated DNA structure-specific nuclease and BLM partner for replication fork restart. We find that elevated EXO5 in tumors correlates with increased mutation loads and poor patient survival, suggesting that EXO5 upregulation has oncogenic potential. Structural, mechanistic, and mutational analyses of EXO5 and EXO5-DNA complexes reveal a single-stranded DNA binding channel with an adjacent ATR phosphorylation motif (T88Q89) that regulates EXO5 nuclease activity and BLM binding identified by mass spectrometric analysis. EXO5 phospho-mimetic mutant rescues the restart defect from EXO5 depletion that decreases fork progression, DNA damage repair, and cell survival. EXO5 depletion furthermore rescues survival of FANCA-deficient cells and indicates EXO5 functions epistatically with SMARCAL1 and BLM. Thus, an EXO5 axis connects ATR and BLM in directing replication fork restart.
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Affiliation(s)
- Shashank Hambarde
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA; Department of Neurosurgery, The Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Chi-Lin Tsai
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Raj K Pandita
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Albino Bacolla
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Anirban Maitra
- Sheikh Ahmed Center for Pancreatic Cancer Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Vijay Charaka
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Clayton R Hunt
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Rakesh Kumar
- School of Biotechnology, Shri Mata Vashino Devi University, Katra, Jammu and Kashmir, 182320, India
| | - Oliver Limbo
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Remy Le Meur
- Departments of Biochemistry and Chemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Walter J Chazin
- Departments of Biochemistry and Chemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Susan E Tsutakawa
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Paul Russell
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Katharina Schlacher
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Tej K Pandita
- Department of Radiation Oncology, The Houston Methodist Research Institute, Houston, TX 77030, USA; Department of Neurosurgery, The Houston Methodist Research Institute, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - John A Tainer
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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11
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Thompson MK, Sobol RW, Prakash A. Exploiting DNA Endonucleases to Advance Mechanisms of DNA Repair. BIOLOGY 2021; 10:530. [PMID: 34198612 PMCID: PMC8232306 DOI: 10.3390/biology10060530] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/09/2021] [Accepted: 06/11/2021] [Indexed: 12/17/2022]
Abstract
The earliest methods of genome editing, such as zinc-finger nucleases (ZFN) and transcription activator-like effector nucleases (TALENs), utilize customizable DNA-binding motifs to target the genome at specific loci. While these approaches provided sequence-specific gene-editing capacity, the laborious process of designing and synthesizing recombinant nucleases to recognize a specific target sequence, combined with limited target choices and poor editing efficiency, ultimately minimized the broad utility of these systems. The discovery of clustered regularly interspaced short palindromic repeat sequences (CRISPR) in Escherichia coli dates to 1987, yet it was another 20 years before CRISPR and the CRISPR-associated (Cas) proteins were identified as part of the microbial adaptive immune system, by targeting phage DNA, to fight bacteriophage reinfection. By 2013, CRISPR/Cas9 systems had been engineered to allow gene editing in mammalian cells. The ease of design, low cytotoxicity, and increased efficiency have made CRISPR/Cas9 and its related systems the designer nucleases of choice for many. In this review, we discuss the various CRISPR systems and their broad utility in genome manipulation. We will explore how CRISPR-controlled modifications have advanced our understanding of the mechanisms of genome stability, using the modulation of DNA repair genes as examples.
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Affiliation(s)
- Marlo K. Thompson
- Mitchell Cancer Institute, University of South Alabama Health, Mobile, AL 36604, USA; (M.K.T.); (R.W.S.)
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
| | - Robert W. Sobol
- Mitchell Cancer Institute, University of South Alabama Health, Mobile, AL 36604, USA; (M.K.T.); (R.W.S.)
- Department of Pharmacology, University of South Alabama, Mobile, AL 36688, USA
| | - Aishwarya Prakash
- Mitchell Cancer Institute, University of South Alabama Health, Mobile, AL 36604, USA; (M.K.T.); (R.W.S.)
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA
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12
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Wu C, Tang D, Cheng J, Hu D, Yang Z, Ma X, He H, Yao S, Fu TM, Yu Y, Chen Q. Mechanisms of spacer acquisition by sequential assembly of the adaptation module in Synechocystis. Nucleic Acids Res 2021; 49:2973-2984. [PMID: 33619565 PMCID: PMC7969031 DOI: 10.1093/nar/gkab105] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/03/2021] [Accepted: 02/09/2021] [Indexed: 02/05/2023] Open
Abstract
CRISPR–Cas immune systems process and integrate short fragments of DNA from new invaders as spacers into the host CRISPR locus to establish molecular memory of prior infection, which is also known as adaptation in the field. Some CRISPR–Cas systems rely on Cas1 and Cas2 to complete the adaptation process, which has been characterized in a few systems. In contrast, many other CRISPR–Cas systems require an additional factor of Cas4 for efficient adaptation, the mechanism of which remains less understood. Here we present biochemical reconstitution of the Synechocystis sp. PCC6803 type I-D adaptation system, X-ray crystal structures of Cas1–Cas2–prespacer complexes, and negative stained electron microscopy structure of the Cas4–Cas1 complex. Cas4 and Cas2 compete with each other to interact with Cas1. In the absence of prespacer, Cas4 but not Cas2 assembles with Cas1 into a very stable complex for processing the prespacer. Strikingly, the Cas1-prespacer complex develops a higher binding affinity toward Cas2 to form the Cas1–Cas2–prespacer ternary complex for integration. Together, we show a two-step sequential assembly mechanism for the type I-D adaptation module of Synechocystis, in which Cas4–Cas1 and Cas1–Cas2 function as two exclusive complexes for prespacer processing, capture, and integration.
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Affiliation(s)
- Chengyong Wu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Dongmei Tang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Jie Cheng
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Daojun Hu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Zejing Yang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Xue Ma
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Haihuai He
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Shaohua Yao
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Tian-Min Fu
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210, USA.,The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Yamei Yu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Qiang Chen
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
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13
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Wimmer F, Beisel CL. CRISPR-Cas Systems and the Paradox of Self-Targeting Spacers. Front Microbiol 2020; 10:3078. [PMID: 32038537 PMCID: PMC6990116 DOI: 10.3389/fmicb.2019.03078] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 12/19/2019] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas immune systems in bacteria and archaea record prior infections as spacers within each system’s CRISPR arrays. Spacers are normally derived from invasive genetic material and direct the immune system to complementary targets as part of future infections. However, not all spacers appear to be derived from foreign genetic material and instead can originate from the host genome. Their presence poses a paradox, as self-targeting spacers would be expected to induce an autoimmune response and cell death. In this review, we discuss the known frequency of self-targeting spacers in natural CRISPR-Cas systems, how these spacers can be incorporated into CRISPR arrays, and how the host can evade lethal attack. We also discuss how self-targeting spacers can become the basis for alternative functions performed by CRISPR-Cas systems that extend beyond adaptive immunity. Overall, the acquisition of genome-targeting spacers poses a substantial risk but can aid in the host’s evolution and potentially lead to or support new functionalities.
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Affiliation(s)
- Franziska Wimmer
- Helmholtz Institute for RNA-Based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - 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
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14
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Cas4 Facilitates PAM-Compatible Spacer Selection during CRISPR Adaptation. Cell Rep 2019; 22:3377-3384. [PMID: 29590607 PMCID: PMC5896167 DOI: 10.1016/j.celrep.2018.02.103] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 01/25/2018] [Accepted: 02/27/2018] [Indexed: 12/20/2022] Open
Abstract
CRISPR-Cas systems adapt their immunological memory against their invaders by integrating short DNA fragments into clustered regularly interspaced short palindromic repeat (CRISPR) loci. While Cas1 and Cas2 make up the core machinery of the CRISPR integration process, various class I and II CRISPR-Cas systems encode Cas4 proteins for which the role is unknown. Here, we introduced the CRISPR adaptation genes cas1, cas2, and cas4 from the type I-D CRISPR-Cas system of Synechocystis sp. 6803 into Escherichia coli and observed that cas4 is strictly required for the selection of targets with protospacer adjacent motifs (PAMs) conferring I-D CRISPR interference in the native host Synechocystis. We propose a model in which Cas4 assists the CRISPR adaptation complex Cas1-2 by providing DNA substrates tailored for the correct PAM. Introducing functional spacers that target DNA sequences with the correct PAM is key to successful CRISPR interference, providing a better chance of surviving infection by mobile genetic elements. Cas4 facilitates the integration of PAM-compatible spacers Spacer length variation is dictated by Cas1-2 Cas4 shortens spacer length Cas4-selected PAMs license type I-D CRISPR interference
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15
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Yang C, Wu R, Liu H, Chen Y, Gao Y, Chen X, Li Y, Ma J, Li J, Gan J. Structural insights into DNA degradation by human mitochondrial nuclease MGME1. Nucleic Acids Res 2019; 46:11075-11088. [PMID: 30247721 PMCID: PMC6237815 DOI: 10.1093/nar/gky855] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 09/11/2018] [Indexed: 01/16/2023] Open
Abstract
Mitochondrial nucleases play important roles in accurate maintenance and correct metabolism of mtDNA, the own genetic materials of mitochondria that are passed exclusively from mother to child. MGME1 is a highly conserved DNase that was discovered recently. Mutations in MGME1-coding gene lead to severe mitochondrial syndromes characterized by external ophthalmoplegia, emaciation, and respiratory failure in humans. Unlike many other nucleases that are distributed in multiple cellular organelles, human MGME1 is a mitochondria-specific nuclease; therefore, it can serve as an ideal target for treating related syndromes. Here, we report one HsMGME1-Mn2+ complex and three different HsMGME1-DNA complex structures. In combination with in vitro cleavage assays, our structures reveal the detailed molecular basis for substrate DNA binding and/or unwinding by HsMGME1. Besides the conserved two-cation-assisted catalytic mechanism, structural analysis of HsMGME1 and comparison with homologous proteins also clarified substrate binding and cleavage directionalities of the DNA double-strand break repair complexes RecBCD and AddAB.
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Affiliation(s)
- Chun Yang
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Ruiqi Wu
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Hehua Liu
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China.,State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Yiqing Chen
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Yanqing Gao
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Xi Chen
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Yangyang Li
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Jinbiao Ma
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Jixi Li
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China.,Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Jianhua Gan
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200433, China
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16
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Cas4 Nucleases Can Effect Specific Integration of CRISPR Spacers. J Bacteriol 2019; 201:JB.00747-18. [PMID: 30936372 DOI: 10.1128/jb.00747-18] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 03/26/2019] [Indexed: 01/19/2023] Open
Abstract
Clustered regularly interspaced short palindromic repeat (CRISPR)-Cas systems incorporate short DNA fragments from invasive genetic elements into host CRISPR arrays in order to generate host immunity. Recently, we demonstrated that the Csa3a regulator protein triggers CCN protospacer-adjacent motif (PAM)-dependent CRISPR spacer acquisition in the subtype I-A CRISPR-Cas system of Sulfolobus islandicus However, the mechanisms underlying specific protospacer selection and spacer insertion remained unclear. Here, we demonstrate that two Cas4 family proteins (Cas4 and Csa1) have essential roles (i) in recognizing the 5' PAM and 3' nucleotide motif of protospacers and (ii) in determining both the spacer length and its orientation. Furthermore, we identify amino acid residues of the Cas4 proteins that facilitate these functions. Overexpression of the Cas4 and Csa1 proteins, and also that of an archaeal virus-encoded Cas4 protein, resulted in strongly reduced adaptation efficiency, and the former proteins yielded a high incidence of PAM-dependent atypical spacer integration or of PAM-independent spacer integration. We further demonstrated that in plasmid challenge experiments, overexpressed Cas4-mediated defective spacer acquisition in turn potentially enabled targeted DNA to escape subtype I-A CRISPR-Cas interference. In summary, these results define the specific involvement of diverse Cas4 proteins in in vivo CRISPR spacer acquisition. Furthermore, we provide support for an anti-CRISPR role for virus-encoded Cas4 proteins that involves compromising CRISPR-Cas interference activity by hindering spacer acquisition.IMPORTANCE The Cas4 family endonuclease is an essential component of the adaptation module in many variants of CRISPR-Cas adaptive immunity systems. The Crenarchaeota Sulfolobus islandicus REY15A carries two cas4 genes (cas4 and csa1) linked to the CRISPR arrays. Here, we demonstrate that Cas4 and Csa1 are essential to CRISPR spacer acquisition in this organism. Both proteins specify the upstream and downstream conserved nucleotide motifs of the protospacers and define the spacer length and orientation in the acquisition process. Conserved amino acid residues, in addition to those recently reported, were identified to be important for these functions. More importantly, overexpression of the Sulfolobus viral Cas4 abolished spacer acquisition, providing support for an anti-CRISPR role for virus-encoded Cas4 proteins that inhibit spacer acquisition.
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17
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Lee H, Dhingra Y, Sashital DG. The Cas4-Cas1-Cas2 complex mediates precise prespacer processing during CRISPR adaptation. eLife 2019; 8:44248. [PMID: 31021314 PMCID: PMC6519985 DOI: 10.7554/elife.44248] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 04/19/2019] [Indexed: 12/15/2022] Open
Abstract
CRISPR adaptation immunizes bacteria and archaea against viruses. During adaptation, the Cas1-Cas2 complex integrates fragments of invader DNA as spacers in the CRISPR array. Recently, an additional protein Cas4 has been implicated in selection and processing of prespacer substrates for Cas1-Cas2, although this mechanism remains unclear. We show that Cas4 interacts directly with Cas1-Cas2 forming a Cas4-Cas1-Cas2 complex that captures and processes prespacers prior to integration. Structural analysis of the Cas4-Cas1-Cas2 complex reveals two copies of Cas4 that closely interact with the two integrase active sites of Cas1, suggesting a mechanism for substrate handoff following processing. We also find that the Cas4-Cas1-Cas2 complex processes single-stranded DNA provided in cis or in trans with a double-stranded DNA duplex. Cas4 cleaves precisely upstream of PAM sequences, ensuring the acquisition of functional spacers. Our results explain how Cas4 cleavage coordinates with Cas1-Cas2 integration and defines the exact cleavage sites and specificity of Cas4. Many people have now heard of CRISPR, or CRISPR-Cas9, as a gene editing technology. Yet CRISPR evolved in bacteria to protect them against viral infections. While parts of the CRISPR system are now being widely used, the research community still does not know everything about how the system operates in its natural setting. In bacteria, CRISPR protects against infection by making lasting records of viruses a cell has encountered. It cuts short sections from the viral DNA and keeps them as a way to fight the virus if it ever returns. The key proteins in collecting and storing the virus DNA are called Cas1, Cas2 and Cas4. Previous work suggests that Cas4 is important for cutting suitable lengths of DNA for storage. Yet, how Cas4, Cas1 and Cas2 work together to select, cut and store DNA is not well studied. Lee et al. have now used electron microscopy to examine how Cas1, Cas2 and Cas4 cooperate in the CRISPR system. The proteins studied came from bacteria called Bacillus halodurans. The structure revealed direct links between the Cas1 and Cas4 proteins that likely help to ensure these proteins are coordinated correctly to cut and store the DNA sections. Specifically, it showed that two Cas4 proteins interact with the two key active sites of Cas1. The findings also highlight that Cas4 cuts DNA at specific locations to make sure the resulting DNA sections are suitable for CRISPR protection. The close association between Cas1 and Cas4 could be a critical aspect of the reliability of the CRISPR system in protecting bacteria from viruses. There are more bacteria on Earth than any other living thing. Understanding their biology has wide ranging environmental, health and bioengineering applications. In addition, learning more about the CRISPR system could further expand its potential to drive revolutionary biotechnology tools derived from these bacterial immune systems.
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Affiliation(s)
- Hayun Lee
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, United States
| | - Yukti Dhingra
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, United States
| | - Dipali G Sashital
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, United States
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18
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Caldwell BJ, Bell CE. Structure and mechanism of the Red recombination system of bacteriophage λ. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 147:33-46. [PMID: 30904699 DOI: 10.1016/j.pbiomolbio.2019.03.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 03/05/2019] [Accepted: 03/15/2019] [Indexed: 01/27/2023]
Abstract
While much of this volume focuses on mammalian DNA repair systems that are directly involved in genome stability and cancer, it is important to still be mindful of model systems from prokaryotes. Herein we review the Red recombination system of bacteriophage λ, which consists of an exonuclease for resecting dsDNA ends, and a single-strand annealing protein (SSAP) for binding the resulting 3'-overhang and annealing it to a complementary strand. The genetics and biochemistry of Red have been studied for over 50 years, in work that has laid much of the foundation for understanding DNA recombination in higher eukaryotes. In fact, the Red exonuclease (λ exo) is homologous to Dna2, a nuclease involved in DNA end-resection in eukaryotes, and the Red annealing protein (Redβ) is homologous to Rad52, the primary SSAP in eukaryotes. While eukaryotic recombination involves an elaborate network of proteins that is still being unraveled, the phage systems are comparatively simple and streamlined, yet still encompass the fundamental features of recombination, namely DNA end-resection, homologous pairing (annealing), and a coupling between them. Moreover, the Red system has been exploited in powerful methods for bacterial genome engineering that are important for functional genomics and systems biology. However, several mechanistic aspects of Red, particularly the action of the annealing protein, remain poorly understood. This review will focus on the proteins of the Red recombination system, with particular attention to structural and mechanistic aspects, and how the lessons learned can be applied to eukaryotic systems.
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Affiliation(s)
- Brian J Caldwell
- Ohio State Biochemistry Program, The Ohio State University, 484 West 12th Avenue, Columbus, OH, 43210, USA; Department of Biological Chemistry and Pharmacology, The Ohio State University, 1060 Carmack Road, Columbus, OH, 43210, USA
| | - Charles E Bell
- Ohio State Biochemistry Program, The Ohio State University, 484 West 12th Avenue, Columbus, OH, 43210, USA; Department of Biological Chemistry and Pharmacology, The Ohio State University, 1060 Carmack Road, Columbus, OH, 43210, USA; Department of Chemistry and Biochemistry, 484 West 12th Avenue, 1060 Carmack Road, Columbus, OH, 43210, USA.
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19
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Goethe M, Fita I, Rubi JM. Entropic Stabilization of Cas4 Protein SSO0001 Predicted with Popcoen. ENTROPY (BASEL, SWITZERLAND) 2018; 20:e20080580. [PMID: 33265669 PMCID: PMC7513108 DOI: 10.3390/e20080580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 07/27/2018] [Accepted: 07/28/2018] [Indexed: 06/12/2023]
Abstract
Popcoen is a method for configurational entropy estimation of proteins based on machine-learning. Entropy is predicted with an artificial neural network which was trained on simulation trajectories of a large set of representative proteins. Popcoen is extremely fast compared to other approaches based on the sampling of a multitude of microstates. Consequently, Popcoen can be incorporated into a large class of protein software which currently neglects configurational entropy for performance reasons. Here, we apply Popcoen to various conformations of the Cas4 protein SSO0001 of Sulfolobus solfataricus, a protein that assembles to a decamer of known toroidal shape. We provide numerical evidence that the native state (NAT) of a SSO0001 monomer has a similar structure to the protomers of the oligomer, where NAT of the monomer is stabilized mainly entropically. Due to its large amount of configurational entropy, NAT has lower free energy than alternative conformations of very low enthalpy and solvation free-energy. Hence, SSO0001 serves as an example case where neglecting configurational entropy leads to incorrect conclusion. Our results imply that no refolding of the subunits is required during oligomerization which suggests that configurational entropy is employed by nature to largely enhance the rate of assembly.
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Affiliation(s)
- Martin Goethe
- Department of Condensed Matter Physics, University of Barcelona, Carrer Martí i Franquès 1, 08028 Barcelona, Spain
- Department of Inorganic and Organic Chemistry, University of Barcelona, Carrer Martí i Franquès 1, 08028 Barcelona, Spain
| | - Ignacio Fita
- Molecular Biology Institute of Barcelona (IBMB-CSIC, Maria de Maeztu Unit of Excellence), Carrer Baldiri Reixac 4-8, 08028 Barcelona, Spain
| | - J. Miguel Rubi
- Department of Condensed Matter Physics, University of Barcelona, Carrer Martí i Franquès 1, 08028 Barcelona, Spain
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20
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Goodman DA, Stedman KM. Comparative genetic and genomic analysis of the novel fusellovirus Sulfolobus spindle-shaped virus 10. Virus Evol 2018; 4:vey022. [PMID: 30094064 PMCID: PMC6080066 DOI: 10.1093/ve/vey022] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Viruses that infect thermophilic Archaea are unique in both their structure and genetic makeup. The lemon-shaped fuselloviruses—which infect members of the order Sulfolobales, growing optimally at 80 °C and pH 3—are some of the most ubiquitous and best studied viruses of the thermoacidophilic Archaea. Nonetheless, much remains to be learned about these viruses. In order to investigate fusellovirus evolution, we have isolated and characterized a novel fusellovirus, Sulfolobus spindle-shaped virus 10 (formerly SSV-L1). Comparative genomic analyses highlight significant similarity with both SSV8 and SSV9, as well as conservation of promoter elements within the Fuselloviridae. SSV10 encodes five ORFs with no homology within or outside of the Fuselloviridae, as well as a putatively functional Cas4-like ORF, which may play a role in evading CRISPR-mediated host defenses. Moreover, we demonstrate the ability of SSV10 to withstand mutation in a fashion consistent with mutagenesis in SSV1.
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Affiliation(s)
- David A Goodman
- Biology Department, Center for Life in Extreme Environments, Portland State University, Portland, OR, USA
| | - Kenneth M Stedman
- Biology Department, Center for Life in Extreme Environments, Portland State University, Portland, OR, USA
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21
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Shiimori M, Garrett SC, Graveley BR, Terns MP. Cas4 Nucleases Define the PAM, Length, and Orientation of DNA Fragments Integrated at CRISPR Loci. Mol Cell 2018; 70:814-824.e6. [PMID: 29883605 DOI: 10.1016/j.molcel.2018.05.002] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 04/27/2018] [Accepted: 05/01/2018] [Indexed: 11/24/2022]
Abstract
To achieve adaptive and heritable immunity against viruses and other mobile genetic elements, CRISPR-Cas systems must capture and store short DNA fragments (spacers) from these foreign elements into host genomic CRISPR arrays. This process is catalyzed by conserved Cas1/Cas2 integration complexes, but the specific roles of another highly conserved protein linked to spacer acquisition, the Cas4 nuclease, are just now emerging. Here, we show that two Cas4 nucleases (Cas4-1 and Cas4-2) play critical roles in CRISPR spacer acquisition in Pyrococcus furiosus. The nuclease activities of both Cas4 proteins are required to process protospacers to the correct size. Cas4-1 specifies the upstream PAM (protospacer adjacent motif), while Cas4-2 specifies the conserved downstream motif. Both Cas4 proteins ensure CRISPR spacer integration in a defined orientation leading to CRISPR immunity. Collectively, these findings provide in vivo evidence for critical roles of Cas4 nucleases in protospacer generation and functional spacer integration at CRISPR arrays.
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Affiliation(s)
- Masami Shiimori
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Sandra C 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 Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA; Department of Genetics, University of Georgia, Athens, GA 30602, USA; Department of Microbiology, University of Georgia, Athens, GA 30602, USA.
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22
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Dou C, Yu M, Gu Y, Wang J, Yin K, Nie C, Zhu X, Qi S, Wei Y, Cheng W. Structural and Mechanistic Analyses Reveal a Unique Cas4-like Protein in the Mimivirus Virophage Resistance Element System. iScience 2018; 3:1-10. [PMID: 30428313 PMCID: PMC6137704 DOI: 10.1016/j.isci.2018.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 02/19/2018] [Accepted: 03/13/2018] [Indexed: 02/05/2023] Open
Abstract
A clustered regularly interspaced short palindromic repeats (CRISPR)-like “mimivirus virophage resistance element” (MIMIVIRE) system, which contains specific cascade genes and a CRISPR array against virophages, was reported in mimiviruses. An essential component of the MIMIVIRE system is R354, encoding a nuclease and a likely functional homolog of Cas4. Here we show that R354 is a dual nuclease with both exonuclease and endonuclease activities. Structural analysis revealed that the catalytic core domain of R354 is similar to those of Cas4 and λ exonuclease despite their low sequence identity. R354 forms a homodimer that is important for its exonuclease but not endonuclease activity. Structural comparisons between the active and semi-active states of R354 demonstrated that an activation loop adjacent to the catalytic site is critical for enzymatic activity. Overall, the results suggest that R354 belongs to a novel MIMIVIRE system involved in innate virus immunity and provides a template for the identification of new CRISPR systems in other species. The key component of Cas4-like R354 in MIMIVIRE is a dual nuclease Structural insights into R354 indicate that it is fully active as a homodimer The semi-active state of R354 is a monomer
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Affiliation(s)
- Chao Dou
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, 17th, 3rd Section, Southern Renmin Road, Chengdu, 610041, China
| | - Mingjing Yu
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, 17th, 3rd Section, Southern Renmin Road, Chengdu, 610041, China
| | - Yijun Gu
- Shanghai Synchrotron Radiation Facility, Zhangjiang Lab, Zhangheng Road 239, Pudong District, Shanghai, 201203, China
| | - Jinjing Wang
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, 17th, 3rd Section, Southern Renmin Road, Chengdu, 610041, China
| | - Kun Yin
- Shandong Academy of Medical Sciences, Shandong Institute of Parasitic Disease, Jining, Shandong 272033, China
| | - Chunlai Nie
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, 17th, 3rd Section, Southern Renmin Road, Chengdu, 610041, China
| | - Xiaofeng Zhu
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, 17th, 3rd Section, Southern Renmin Road, Chengdu, 610041, China
| | - Shiqian Qi
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, 17th, 3rd Section, Southern Renmin Road, Chengdu, 610041, China
| | - Yuquan Wei
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, 17th, 3rd Section, Southern Renmin Road, Chengdu, 610041, China
| | - Wei Cheng
- Division of Respiratory and Critical Care Medicine, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy, 17th, 3rd Section, Southern Renmin Road, Chengdu, 610041, China.
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Cas4-Dependent Prespacer Processing Ensures High-Fidelity Programming of CRISPR Arrays. Mol Cell 2018; 70:48-59.e5. [PMID: 29602742 DOI: 10.1016/j.molcel.2018.03.003] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 02/13/2018] [Accepted: 02/28/2018] [Indexed: 12/26/2022]
Abstract
CRISPR-Cas immune systems integrate short segments of foreign DNA as spacers into the host CRISPR locus to provide molecular memory of infection. Cas4 proteins are widespread in CRISPR-Cas systems and are thought to participate in spacer acquisition, although their exact function remains unknown. Here we show that Bacillus halodurans type I-C Cas4 is required for efficient prespacer processing prior to Cas1-Cas2-mediated integration. Cas4 interacts tightly with the Cas1 integrase, forming a heterohexameric complex containing two Cas1 dimers and two Cas4 subunits. In the presence of Cas1 and Cas2, Cas4 processes double-stranded substrates with long 3' overhangs through site-specific endonucleolytic cleavage. Cas4 recognizes PAM sequences within the prespacer and prevents integration of unprocessed prespacers, ensuring that only functional spacers will be integrated into the CRISPR array. Our results reveal the critical role of Cas4 in maintaining fidelity during CRISPR adaptation, providing a structural and mechanistic model for prespacer processing and integration.
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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: 55] [Impact Index Per Article: 9.2] [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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Kaushik V, Verma VV, Goel M. Functional divergence and comparative in-silico study of Cas4 proteins of DUF83 class. J Mol Recognit 2017; 31:e2694. [PMID: 29243852 DOI: 10.1002/jmr.2694] [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: 06/13/2017] [Revised: 11/14/2017] [Accepted: 11/14/2017] [Indexed: 11/08/2022]
Abstract
Clustered Regularly Interspaced Short Palindromic Repeats-CRISPR associated (CRISPR-Cas) systems present in genomes of bacteria and archaea have been the focus of many research studies recently. The Cas4 proteins of these systems are thought to be responsible for the adaptation step in the CRISPR mechanism. Cas4 proteins exhibit low sequence similarity among themselves and are currently classified into 2 main classes: DUF83 and DUF911. The characteristic features of Cas4 proteins belonging to DUF83 class have been elucidated by determining the structures of Cas4 protein from Sulfolobus solfataricus and Pyrobaculum calidifontis. Although, both Cas4 proteins characterized structurally are of same DUF83 class, these 2 proteins do exhibit significant biochemical and functional differences. The aim of the present study was to explore the structural and evolutionary features responsible for these differences. Our study predicts residues which might be responsible for such differences. Functional divergence analysis was used to predict sites exhibiting type I divergence, where certain amino acids are conserved in 1 clade whereas the same site is highly variable in the other clade. Our intra-molecular interaction analysis reinforces the influence of such divergence sites on the other functionally important amino acids. In general, this study identifies some of the divergence hotspots that could be the focus of future experimental studies for better understanding of Cas4 enzymatic activity in CRISPR mechanism.
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Affiliation(s)
- Vineeta Kaushik
- Department of Biophysics, University of Delhi, New Delhi, India
| | - Ved Vrat Verma
- Department of Biophysics, University of Delhi, New Delhi, India
| | - Manisha Goel
- Department of Biophysics, University of Delhi, New Delhi, India
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Hudaiberdiev S, Shmakov S, Wolf YI, Terns MP, Makarova KS, Koonin EV. Phylogenomics of Cas4 family nucleases. BMC Evol Biol 2017; 17:232. [PMID: 29179671 PMCID: PMC5704561 DOI: 10.1186/s12862-017-1081-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 11/16/2017] [Indexed: 12/31/2022] Open
Abstract
Background The Cas4 family endonuclease is a component of the adaptation module in many variants of CRISPR-Cas adaptive immunity systems. Unlike most of the other Cas proteins, Cas4 is often encoded outside CRISPR-cas loci (solo-Cas4) and is also found in mobile genetic elements (MGE-Cas4). Results As part of our ongoing investigation of CRISPR-Cas evolution, we explored the phylogenomics of the Cas4 family. About 90% of the archaeal genomes encode Cas4 compared to only about 20% of the bacterial genomes. Many archaea encode both the CRISPR-associated form (CAS-Cas4) and solo-Cas4, whereas in bacteria, this combination is extremely rare. The solo-cas4 genes are over-represented in environmental bacteria and archaea with small genomes that typically lack CRISPR-Cas, suggesting that Cas4 could perform uncharacterized defense or repair functions in these microbes. Phylogenomic analysis indicates that both the CRISPR-associated cas4 genes are often transferred horizontally but almost exclusively, as part of the adaptation module. The evolutionary integrity of the adaptation module sharply contrasts the rampant shuffling of CRISPR-cas modules whereby a given variant of the adaptation module can combine with virtually any effector module. The solo-cas4 genes evolve primarily via vertical inheritance and are subject only to occasional horizontal transfer. The selection pressure on cas4 genes does not substantially differ between CAS-Cas4 and solo-cas4, and is close to the genomic median. Thus, cas4 genes, similarly to cas1 and cas2, evolve similarly to ‘regular’ microbial genes involved in various cellular functions, showing no evidence of direct involvement in virus-host arms races. A notable feature of the Cas4 family evolution is the frequent recruitment of cas4 genes by various mobile genetic elements (MGE), particularly, archaeal viruses. The functions of Cas4 in these elements are unknown and potentially might involve anti-defense roles. Conclusions Unlike most of the other Cas proteins, Cas4 family members are as often encoded by stand-alone genes as they are incorporated in CRISPR-Cas systems. In addition, cas4 genes were repeatedly recruited by MGE, perhaps, for anti-defense functions. Experimental characterization of the solo and MGE-encoded Cas4 nucleases is expected to reveal currently uncharacterized defense and anti-defense systems and their interactions with CRISPR-Cas systems. Electronic supplementary material The online version of this article (10.1186/s12862-017-1081-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sanjarbek Hudaiberdiev
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, USA
| | - Sergey Shmakov
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, USA.,Skolkovo Institute of Science and Technology, Skolkovo, 143025, Russia
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, USA
| | - Michael P Terns
- Departments of Biochemistry and Molecular Biology, Genetics, and Microbiology, University of Georgia, Athens, GA, USA
| | - Kira S Makarova
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, USA
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, 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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Zanello P. The competition between chemistry and biology in assembling iron–sulfur derivatives. Molecular structures and electrochemistry. Part V. {[Fe4S4](SCysγ)4} proteins. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2016.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Stiban J, So M, Kaguni LS. Iron-Sulfur Clusters in Mitochondrial Metabolism: Multifaceted Roles of a Simple Cofactor. BIOCHEMISTRY (MOSCOW) 2017; 81:1066-1080. [PMID: 27908232 DOI: 10.1134/s0006297916100059] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Iron-sulfur metabolism is essential for cellular function and is a key process in mitochondria. In this review, we focus on the structure and assembly of mitochondrial iron-sulfur clusters and their roles in various metabolic processes that occur in mitochondria. Iron-sulfur clusters are crucial in mitochondrial respiration, in which they are required for the assembly, stability, and function of respiratory complexes I, II, and III. They also serve important functions in the citric acid cycle, DNA metabolism, and apoptosis. Whereas the identification of iron-sulfur containing proteins and their roles in numerous aspects of cellular function has been a long-standing research area, that in mitochondria is comparatively recent, and it is likely that their roles within mitochondria have been only partially revealed. We review the status of the field and provide examples of other cellular iron-sulfur proteins to highlight their multifarious roles.
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Affiliation(s)
- Johnny Stiban
- Birzeit University, Department of Biology and Biochemistry, West Bank Birzeit, 627, Palestine.
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Wright AV, Nuñez JK, Doudna JA. Biology and Applications of CRISPR Systems: Harnessing Nature's Toolbox for Genome Engineering. Cell 2016; 164:29-44. [PMID: 26771484 DOI: 10.1016/j.cell.2015.12.035] [Citation(s) in RCA: 684] [Impact Index Per Article: 85.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Indexed: 12/26/2022]
Abstract
Bacteria and archaea possess a range of defense mechanisms to combat plasmids and viral infections. Unique among these are the CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR associated) systems, which provide adaptive immunity against foreign nucleic acids. CRISPR systems function by acquiring genetic records of invaders to facilitate robust interference upon reinfection. In this Review, we discuss recent advances in understanding the diverse mechanisms by which Cas proteins respond to foreign nucleic acids and how these systems have been harnessed for precision genome manipulation in a wide array of organisms.
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Affiliation(s)
- Addison V Wright
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - James K Nuñez
- Department of Molecular and Cell Biology, 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; Howard Hughes Medical Institute HHMI, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA; Center for RNA Systems Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Innovative Genomics Initiative, University of California, Berkeley, Berkeley, CA 94720, USA; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, Berkeley, CA 94720, USA.
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Hooton SPT, Brathwaite KJ, Connerton IF. The Bacteriophage Carrier State of Campylobacter jejuni Features Changes in Host Non-coding RNAs and the Acquisition of New Host-derived CRISPR Spacer Sequences. Front Microbiol 2016; 7:355. [PMID: 27047470 PMCID: PMC4804229 DOI: 10.3389/fmicb.2016.00355] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 03/07/2016] [Indexed: 12/21/2022] Open
Abstract
Incorporation of self-derived CRISPR DNA protospacers in Campylobacter jejuni PT14 occurs in the presence of bacteriophages encoding a CRISPR-like Cas4 protein. This phenomenon was evident in carrier state infections where both bacteriophages and host are maintained for seemingly indefinite periods as stable populations following serial passage. Carrier state cultures of C. jejuni PT14 have greater aerotolerance in nutrient limited conditions, and may have arisen as an evolutionary response to selective pressures imposed during periods in the extra-intestinal environment. A consequence of this is that bacteriophage and host remain associated and able to survive transition periods where the chances of replicative success are greatly diminished. The majority of the bacteriophage population do not commit to lytic infection, and conversely the bacterial population tolerates low-level bacteriophage replication. We recently examined the effects of Campylobacter bacteriophage/C. jejuni PT14 CRISPR spacer acquisition using deep sequencing strategies of DNA and RNA-Seq to analyze carrier state cultures. This approach identified de novo spacer acquisition in C. jejuni PT14 associated with Class III Campylobacter phages CP8/CP30A but spacer acquisition was oriented toward the capture of host DNA. In the absence of bacteriophage predation the CRISPR spacers in uninfected C. jejuni PT14 cultures remain unchanged. A distinct preference was observed for incorporation of self-derived protospacers into the third spacer position of the C. jejuni PT14 CRISPR array, with the first and second spacers remaining fixed. RNA-Seq also revealed the variation in the synthesis of non-coding RNAs with the potential to bind bacteriophage genes and/or transcript sequences.
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Affiliation(s)
- Steven P T Hooton
- Division of Food Sciences, School of Biosciences, University of Nottingham Loughborough, UK
| | - Kelly J Brathwaite
- Division of Food Sciences, School of Biosciences, University of Nottingham Loughborough, UK
| | - Ian F Connerton
- Division of Food Sciences, School of Biosciences, University of Nottingham Loughborough, UK
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Papasimakis N, Fedotov VA, Savinov V, Raybould TA, Zheludev NI. Electromagnetic toroidal excitations in matter and free space. NATURE MATERIALS 2016; 15:263-71. [PMID: 26906961 DOI: 10.1038/nmat4563] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 01/08/2016] [Indexed: 05/20/2023]
Abstract
The toroidal dipole is a localized electromagnetic excitation, distinct from the magnetic and electric dipoles. While the electric dipole can be understood as a pair of opposite charges and the magnetic dipole as a current loop, the toroidal dipole corresponds to currents flowing on the surface of a torus. Toroidal dipoles provide physically significant contributions to the basic characteristics of matter including absorption, dispersion and optical activity. Toroidal excitations also exist in free space as spatially and temporally localized electromagnetic pulses propagating at the speed of light and interacting with matter. We review recent experimental observations of resonant toroidal dipole excitations in metamaterials and the discovery of anapoles, non-radiating charge-current configurations involving toroidal dipoles. While certain fundamental and practical aspects of toroidal electrodynamics remain open for the moment, we envision that exploitation of toroidal excitations can have important implications for the fields of photonics, sensing, energy and information.
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Affiliation(s)
- N Papasimakis
- Optoelectronics Research Centre &Centre for Photonic Metamaterials, University of Southampton, Highfield SO17 1BJ, UK
| | - V A Fedotov
- Optoelectronics Research Centre &Centre for Photonic Metamaterials, University of Southampton, Highfield SO17 1BJ, UK
| | - V Savinov
- Optoelectronics Research Centre &Centre for Photonic Metamaterials, University of Southampton, Highfield SO17 1BJ, UK
| | - T A Raybould
- Optoelectronics Research Centre &Centre for Photonic Metamaterials, University of Southampton, Highfield SO17 1BJ, UK
| | - N I Zheludev
- Optoelectronics Research Centre &Centre for Photonic Metamaterials, University of Southampton, Highfield SO17 1BJ, UK
- TPI and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637378, Singapore
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Abstract
Since the first demonstration that CRISPR-Cas systems provide bacteria and archaea with adaptive immunity against phages and plasmids, numerous studies have yielded key insights into the molecular mechanisms governing how these systems attack and degrade foreign DNA. However, the molecular mechanisms underlying the adaptation stage, in which new immunological memory is formed, have until recently represented a major unresolved question. In this Progress article, we discuss recent discoveries that have shown both how foreign DNA is identified by the CRISPR-Cas adaptation machinery and the molecular basis for its integration into the chromosome to form an immunological memory. Furthermore, we describe the roles of each of the specific CRISPR-Cas components that are involved in memory formation, and consider current models for their evolutionary origin.
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Krupovic M, Cvirkaite-Krupovic V, Prangishvili D, Koonin EV. Evolution of an archaeal virus nucleocapsid protein from the CRISPR-associated Cas4 nuclease. Biol Direct 2015; 10:65. [PMID: 26514828 PMCID: PMC4625639 DOI: 10.1186/s13062-015-0093-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 10/26/2015] [Indexed: 12/23/2022] Open
Abstract
Abstract Many proteins of viruses infecting hyperthermophilic Crenarchaeota have no detectable homologs in current databases, hampering our understanding of viral evolution. We used sensitive database search methods and structural modeling to show that a nucleocapsid protein (TP1) of Thermoproteus tenax virus 1 (TTV1) is a derivative of the Cas4 nuclease, a component of the CRISPR-Cas adaptive immunity system that is encoded also by several archaeal viruses. In TTV1, the Cas4 gene was split into two, with the N-terminal portion becoming TP1, and lost some of the catalytic amino acid residues, apparently resulting in the inactivation of the nuclease. To our knowledge, this is the first described case of exaptation of an enzyme for a virus capsid protein function. Reviewers This article was reviewed by Vivek Anantharaman, Christine Orengo and Mircea Podar. For complete reviews, see the Reviewers’ reports section. Electronic supplementary material The online version of this article (doi:10.1186/s13062-015-0093-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mart Krupovic
- Department of Microbiology, Unité Biologie Moléculaire du Gène chez les Extrêmophiles, Institut Pasteur, Paris, 75015, France.
| | - Virginija Cvirkaite-Krupovic
- Department of Microbiology, Unité Biologie Moléculaire du Gène chez les Extrêmophiles, Institut Pasteur, Paris, 75015, France.
| | - David Prangishvili
- Department of Microbiology, Unité Biologie Moléculaire du Gène chez les Extrêmophiles, Institut Pasteur, Paris, 75015, France.
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, 20894, USA.
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35
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Rollie C, Schneider S, Brinkmann AS, Bolt EL, White MF. Intrinsic sequence specificity of the Cas1 integrase directs new spacer acquisition. eLife 2015; 4. [PMID: 26284603 PMCID: PMC4574026 DOI: 10.7554/elife.08716] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 08/17/2015] [Indexed: 11/13/2022] Open
Abstract
The adaptive prokaryotic immune system CRISPR-Cas provides RNA-mediated protection from invading genetic elements. The fundamental basis of the system is the ability to capture small pieces of foreign DNA for incorporation into the genome at the CRISPR locus, a process known as Adaptation, which is dependent on the Cas1 and Cas2 proteins. We demonstrate that Cas1 catalyses an efficient trans-esterification reaction on branched DNA substrates, which represents the reverse- or disintegration reaction. Cas1 from both Escherichia coli and Sulfolobus solfataricus display sequence specific activity, with a clear preference for the nucleotides flanking the integration site at the leader-repeat 1 boundary of the CRISPR locus. Cas2 is not required for this activity and does not influence the specificity. This suggests that the inherent sequence specificity of Cas1 is a major determinant of the adaptation process.
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Affiliation(s)
- Clare Rollie
- Biomedical Sciences Research Complex, University of St Andrews, St Andrews, United Kingdom
| | - Stefanie Schneider
- Faculty of Medicine, Institute of Cell Biology, University of Duisburg-Essen, Essen, Germany
| | - Anna Sophie Brinkmann
- School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Edward L Bolt
- School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Malcolm F White
- Biomedical Sciences Research Complex, University of St Andrews, St Andrews, United Kingdom
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36
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Guo Y, Kragelund BB, White MF, Peng X. Functional Characterization of a Conserved Archaeal Viral Operon Revealing Single-Stranded DNA Binding, Annealing and Nuclease Activities. J Mol Biol 2015; 427:2179-91. [DOI: 10.1016/j.jmb.2015.03.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/17/2015] [Accepted: 03/18/2015] [Indexed: 11/15/2022]
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Brathwaite KJ, Siringan P, Connerton PL, Connerton IF. Host adaption to the bacteriophage carrier state of Campylobacter jejuni. Res Microbiol 2015; 166:504-15. [PMID: 26004283 PMCID: PMC4534711 DOI: 10.1016/j.resmic.2015.05.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 05/04/2015] [Accepted: 05/06/2015] [Indexed: 02/06/2023]
Abstract
The carrier state of the foodborne pathogen Campylobacter jejuni represents an alternative life cycle whereby virulent bacteriophages can persist in association with host bacteria without commitment to lysogeny. Host bacteria exhibit significant phenotypic changes that improve their ability to survive extra-intestinal environments, but exhibit growth-phase-dependent impairment in motility. We demonstrate that early exponential phase cultures become synchronised with respect to the non-motile phenotype, which corresponds with a reduction in their ability to adhere to and invade intestinal epithelial cells. Comparative transcriptome analyses (RNA-seq) identify changes in gene expression that account for the observed phenotypes: downregulation of stress response genes hrcA, hspR and per and downregulation of the major flagellin flaA with the chemotactic response signalling genes cheV, cheA and cheW. These changes present mechanisms by which the host and bacteriophage can remain associated without lysis, and the cultures survive extra-intestinal transit. These data provide a basis for understanding a critical link in the ecology of the Campylobacter bacteriophage.
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Affiliation(s)
- Kelly J Brathwaite
- Division of Food Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE12 5RD, United Kingdom
| | - Patcharin Siringan
- Division of Food Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE12 5RD, United Kingdom
| | - Phillippa L Connerton
- Division of Food Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE12 5RD, United Kingdom
| | - Ian F Connerton
- Division of Food Sciences, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leicestershire LE12 5RD, United Kingdom.
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Hooton SPT, Connerton IF. Campylobacter jejuni acquire new host-derived CRISPR spacers when in association with bacteriophages harboring a CRISPR-like Cas4 protein. Front Microbiol 2015; 5:744. [PMID: 25601859 PMCID: PMC4283603 DOI: 10.3389/fmicb.2014.00744] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Accepted: 12/09/2014] [Indexed: 01/28/2023] Open
Abstract
Campylobacter jejuni is a worldwide cause of human diarrhoeal disease. Clustered Repetitively Interspaced Palindromic Repeats (CRISPRs) and associated proteins allow Bacteria and Archaea to evade bacteriophage and plasmid infection. Type II CRISPR systems are found in association with combinations of genes encoding the CRISPR-associated Cas1, Cas2, Cas4 or Csn2, and Cas9 proteins. C. jejuni possesses a minimal subtype II-C CRISPR system containing cas1, cas2, and cas9 genes whilst cas4 is notably absent. Cas4 proteins possess 5′-3′ exonuclease activity to create recombinogenic-ends for spacer acquisition. Here we report a conserved Cas4-like protein in Campylobacter bacteriophages that creates a novel split arrangement between the bacteriophage and host that represents a new twist in the bacteriophage/host co-evolutionary arms race. The continuous association of bacteriophage and host in the carrier state life cycle of C. jejuni provided an opportunity to study spacer acquisition in this species. Remarkably all the spacer sequences observed were of host origin. We hypothesize that Campylobacter bacteriophages can use Cas4-like protein to activate spacer acquisition to use host DNA as an effective decoy to bacteriophage DNA. Bacteria that acquire self-spacers and escape phage infection must overcome CRISPR-mediated autoimmunity either by loss of the interference functions leaving them susceptible to foreign DNA incursion or tolerate changes in gene regulation.
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Affiliation(s)
- Steven P T Hooton
- Division of Food Sciences, School of Biosciences, University of Nottingham Loughborough, UK
| | - Ian F Connerton
- Division of Food Sciences, School of Biosciences, University of Nottingham Loughborough, UK
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Beloglazova N, Kuznedelov K, Flick R, Datsenko KA, Brown G, Popovic A, Lemak S, Semenova E, Severinov K, Yakunin AF. CRISPR RNA binding and DNA target recognition by purified Cascade complexes from Escherichia coli. Nucleic Acids Res 2015; 43:530-43. [PMID: 25488810 PMCID: PMC4288178 DOI: 10.1093/nar/gku1285] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 11/22/2014] [Accepted: 11/24/2014] [Indexed: 12/26/2022] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPRs) and their associated Cas proteins comprise a prokaryotic RNA-guided adaptive immune system that interferes with mobile genetic elements, such as plasmids and phages. The type I-E CRISPR interference complex Cascade from Escherichia coli is composed of five different Cas proteins and a 61-nt-long guide RNA (crRNA). crRNAs contain a unique 32-nt spacer flanked by a repeat-derived 5' handle (8 nt) and a 3' handle (21 nt). The spacer part of crRNA directs Cascade to DNA targets. Here, we show that the E. coli Cascade can be expressed and purified from cells lacking crRNAs and loaded in vitro with synthetic crRNAs, which direct it to targets complementary to crRNA spacer. The deletion of even one nucleotide from the crRNA 5' handle disrupted its binding to Cascade and target DNA recognition. In contrast, crRNA variants with just a single nucleotide downstream of the spacer part bound Cascade and the resulting ribonucleotide complex containing a 41-nt-long crRNA specifically recognized DNA targets. Thus, the E. coli Cascade-crRNA system exhibits significant flexibility suggesting that this complex can be engineered for applications in genome editing and opening the way for incorporation of site-specific labels in crRNA.
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Affiliation(s)
- Natalia Beloglazova
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
| | - Konstantin Kuznedelov
- Waksman Institute of Microbiology, Rutgers, the State University of New Jersey, Piscataway, NJ 08854, USA
| | - Robert Flick
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
| | - Kirill A Datsenko
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Greg Brown
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
| | - Ana Popovic
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
| | - Sofia Lemak
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
| | - Ekaterina Semenova
- Waksman Institute of Microbiology, Rutgers, the State University of New Jersey, Piscataway, NJ 08854, USA
| | - Konstantin Severinov
- Waksman Institute of Microbiology, Rutgers, the State University of New Jersey, Piscataway, NJ 08854, USA Institute of Molecular Genetics, Russian Academy of Sciences, Moscow 123182, Russia
| | - Alexander F Yakunin
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
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40
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Swarts DC, Makarova K, Wang Y, Nakanishi K, Ketting RF, Koonin EV, Patel DJ, van der Oost J. The evolutionary journey of Argonaute proteins. Nat Struct Mol Biol 2014; 21:743-53. [PMID: 25192263 DOI: 10.1038/nsmb.2879] [Citation(s) in RCA: 312] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 07/30/2014] [Indexed: 02/07/2023]
Abstract
Argonaute proteins are conserved throughout all domains of life. Recently characterized prokaryotic Argonaute proteins (pAgos) participate in host defense by DNA interference, whereas eukaryotic Argonaute proteins (eAgos) control a wide range of processes by RNA interference. Here we review molecular mechanisms of guide and target binding by Argonaute proteins, and describe how the conformational changes induced by target binding lead to target cleavage. On the basis of structural comparisons and phylogenetic analyses of pAgos and eAgos, we reconstruct the evolutionary journey of the Argonaute proteins through the three domains of life and discuss how different structural features of pAgos and eAgos relate to their distinct physiological roles.
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Affiliation(s)
- Daan C Swarts
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, the Netherlands
| | - Kira Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Yanli Wang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Kotaro Nakanishi
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, Ohio, USA
| | | | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
| | - John van der Oost
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, the Netherlands
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41
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Zhang J, Pan X, Bell CE. Crystal structure of λ exonuclease in complex with DNA and Ca(2+). Biochemistry 2014; 53:7415-25. [PMID: 25370446 DOI: 10.1021/bi501155q] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Bacteriophage λ exonuclease (λexo) is a ring-shaped homotrimer that resects double-stranded DNA ends in the 5'-3' direction to generate a long 3'-overhang that is a substrate for recombination. λexo is a member of the type II restriction endonuclease-like superfamily of proteins that use a Mg(2+)-dependent mechanism for nucleotide cleavage. A previous structure of λexo in complex with DNA and Mg(2+) was determined using a nuclease defective K131A variant to trap a stable complex. This structure revealed the detailed coordination of the two active site Mg(2+) ions but did not show the interactions involving the side chain of the conserved active site Lys-131 residue. Here, we have determined the crystal structure of wild-type (WT) λexo in complex with the same DNA substrate, but in the presence of Ca(2+) instead of Mg(2+). Surprisingly, there is only one Ca(2+) bound in the active site, near the position of Mg(A) in the structure with Mg(2+). The scissile phosphate is displaced by 2.2 Å relative to its position in the structure with Mg(2+), and the network of interactions involving the attacking water molecule is broken. Thus, the structure does not represent a catalytic configuration. However, the crystal structure does show clear electron density for the side chain of Lys-131, which is held in place by interactions with Gln-157 and Glu-129. By combining the K131A-Mg(2+) and WT-Ca(2+) structures, we constructed a composite model to show the likely interactions of Lys-131 during catalysis. The implications with regard to the catalytic mechanism are discussed.
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Affiliation(s)
- Jinjin Zhang
- Ohio State Biochemistry Program, ‡Department of Molecular and Cellular Biochemistry, and §Department of Chemistry and Biochemistry, The Ohio State University , 1645 Neil Avenue, Columbus, Ohio 43210, United States
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42
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Lemak S, Nocek B, Beloglazova N, Skarina T, Flick R, Brown G, Joachimiak A, Savchenko A, Yakunin AF. The CRISPR-associated Cas4 protein Pcal_0546 from Pyrobaculum calidifontis contains a [2Fe-2S] cluster: crystal structure and nuclease activity. Nucleic Acids Res 2014; 42:11144-55. [PMID: 25200083 PMCID: PMC4176176 DOI: 10.1093/nar/gku797] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Cas4 nucleases constitute a core family of CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) associated proteins, but little is known about their structure and activity. Here we report the crystal structure of the Cas4 protein Pcal_0546 from Pyrobaculum calidifontis, which revealed a monomeric protein with a RecB-like fold and one [2Fe-2S] cluster coordinated by four conserved Cys residues. Pcal_0546 exhibits metal-dependent 5' to 3' exonuclease activity against ssDNA substrates, whereas the Cas4 protein SSO1391 from Sulfolobus solfataricus can cleave ssDNA in both the 5' to 3' and 3' to 5' directions. The active site of Pcal_0546 contains a bound metal ion coordinated by the side chains of Asp123, Glu136, His146, and the main chain carbonyl of Ile137. Site-directed mutagenesis of Pcal_0546 and SSO1391 revealed that the residues of RecB motifs II, III and QhXXY are critical for nuclease activity, whereas mutations of the conserved Cys residues resulted in a loss of the iron-sulfur cluster, but had no effect on DNA cleavage. Our results revealed the biochemical diversity of Cas4 nucleases, which can have different oligomeric states, contain [4Fe-4S] or [2Fe-2S] clusters, and cleave single stranded DNA in different directions producing single-stranded DNA overhangs, which are potential intermediates for the synthesis of new CRISPR spacers.
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Affiliation(s)
- Sofia Lemak
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Boguslaw Nocek
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Natalia Beloglazova
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Tatiana Skarina
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Robert Flick
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Greg Brown
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Andrzej Joachimiak
- Midwest Center for Structural Genomics and Structural Biology Center, Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Alexei Savchenko
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Alexander F Yakunin
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
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43
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Arslan Z, Hermanns V, Wurm R, Wagner R, Pul Ü. Detection and characterization of spacer integration intermediates in type I-E CRISPR-Cas system. Nucleic Acids Res 2014; 42:7884-93. [PMID: 24920831 PMCID: PMC4081107 DOI: 10.1093/nar/gku510] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 05/22/2014] [Accepted: 05/22/2014] [Indexed: 12/26/2022] Open
Abstract
The adaptation against foreign nucleic acids by the CRISPR-Cas system (Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR-associated proteins) depends on the insertion of foreign nucleic acid-derived sequences into the CRISPR array as novel spacers by still unknown mechanism. We identified and characterized in Escherichia coli intermediate states of spacer integration and mapped the integration site at the chromosomal CRISPR array in vivo. The results show that the insertion of new spacers occurs by site-specific nicking at both strands of the leader proximal repeat in a staggered way and is accompanied by joining of the resulting 5'-ends of the repeat strands with the 3'-ends of the incoming spacer. This concerted cleavage-ligation reaction depends on the metal-binding center of Cas1 protein and requires the presence of Cas2. By acquisition assays using plasmid-located CRISPR array with mutated repeat sequences, we demonstrate that the primary sequence of the first repeat is crucial for cleavage of the CRISPR array and the ligation of new spacer DNA.
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Affiliation(s)
- Zihni Arslan
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Veronica Hermanns
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Reinhild Wurm
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Rolf Wagner
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Ümit Pul
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, Universitätsstraße 1, 40225 Düsseldorf, Germany
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44
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van der Oost J, Westra ER, Jackson RN, Wiedenheft B. Unravelling the structural and mechanistic basis of CRISPR-Cas systems. Nat Rev Microbiol 2014; 12:479-92. [PMID: 24909109 PMCID: PMC4225775 DOI: 10.1038/nrmicro3279] [Citation(s) in RCA: 501] [Impact Index Per Article: 50.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Bacteria and archaea have evolved sophisticated adaptive immune systems, known as CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated proteins) systems, which target and inactivate invading viruses and plasmids. Immunity is acquired by integrating short fragments of foreign DNA into CRISPR loci, and following transcription and processing of these loci, the CRISPR RNAs (crRNAs) guide the Cas proteins to complementary invading nucleic acid, which results in target interference. In this Review, we summarize the recent structural and biochemical insights that have been gained for the three major types of CRISPR-Cas systems, which together provide a detailed molecular understanding of the unique and conserved mechanisms of RNA-guided adaptive immunity in bacteria and archaea.
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Affiliation(s)
- John van der Oost
- Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, The Netherlands
| | - Edze R Westra
- 1] Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB Wageningen, The Netherlands. [2] Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9FE, UK
| | - Ryan N Jackson
- Department of Microbiology and Immunology, Montana State University, PO Box 173520, Bozeman, Montana 59717, USA
| | - Blake Wiedenheft
- Department of Microbiology and Immunology, Montana State University, PO Box 173520, Bozeman, Montana 59717, USA
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