1
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Castillo M, Guevara G, Baldanta S, Rodríguez PS, Agudo L, Nogales J, Carrasco AD, Arribas-Aguilar F, Pérez-Pérez J, García JL, Galán B, Navarro Llorens JM. Characterization of Limnospira platensis PCC 9108 R-M and CRISPR-Cas systems. Microbiol Res 2024; 279:127572. [PMID: 38101163 DOI: 10.1016/j.micres.2023.127572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/05/2023] [Accepted: 12/06/2023] [Indexed: 12/17/2023]
Abstract
The filamentous cyanobacterium Limnospira platensis, formerly known as Arthrospira platensis or spirulina, is one of the most commercially important species of microalgae. Due to its high nutritional value, pharmacological and industrial applications it is extensively cultivated on a large commercial scale. Despite its widespread use, its precise manipulation is still under development due to the lack of effective genetic protocols. Genetic transformation of Limnospira has been attempted but the methods reported have not been generally reproducible in other laboratories. Knowledge of the transformation defense mechanisms is essential for understanding its physiology and for broadening their applications. With the aim to understand more about the genetic defenses of L. platensis, in this work we have identified the restriction-modification and CRISPR-Cas systems and we have cloned and characterized thirteen methylases. In parallel, we have also characterized the methylome and orphan methyltransferases using genome-wide analysis of DNA methylation patterns and RNA-seq. The identification and characterization of these enzymes will be a valuable resource to know how this strain avoids being genetically manipulated and for further genomics studies.
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Affiliation(s)
- María Castillo
- Microbial and Plant Biotechnology Department, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
| | - Govinda Guevara
- Department of Biochemistry and Molecular Biology, Facultad de Ciencias Biológicas, Universidad Complutense de Madrid, Av. Complutense s/n, 28040 Madrid, Spain.
| | - Sara Baldanta
- Microbial and Plant Biotechnology Department, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain; Department of Biochemistry and Molecular Biology, Facultad de Ciencias Biológicas, Universidad Complutense de Madrid, Av. Complutense s/n, 28040 Madrid, Spain.
| | - Patricia Suárez Rodríguez
- Department of Biochemistry and Molecular Biology, Facultad de Ciencias Biológicas, Universidad Complutense de Madrid, Av. Complutense s/n, 28040 Madrid, Spain.
| | - Lucía Agudo
- Department of Systems Biology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CNB-CSIC), 28049 Madrid, Spain.
| | - Juan Nogales
- Department of Systems Biology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CNB-CSIC), 28049 Madrid, Spain.
| | - Asunción Díaz Carrasco
- DNA Sequencing facility, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
| | - Fernando Arribas-Aguilar
- SECUGEN SL, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
| | - Julián Pérez-Pérez
- SECUGEN SL, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
| | - José Luis García
- Microbial and Plant Biotechnology Department, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
| | - Beatriz Galán
- Microbial and Plant Biotechnology Department, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
| | - Juana María Navarro Llorens
- Department of Biochemistry and Molecular Biology, Facultad de Ciencias Biológicas, Universidad Complutense de Madrid, Av. Complutense s/n, 28040 Madrid, Spain.
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2
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Parra-Sánchez Á, Antequera-Zambrano L, Martínez-Navarrete G, Zorrilla-Muñoz V, Paz JL, Alvarado YJ, González-Paz L, Fernández E. Comparative Analysis of CRISPR-Cas Systems in Pseudomonas Genomes. Genes (Basel) 2023; 14:1337. [PMID: 37510242 PMCID: PMC10379622 DOI: 10.3390/genes14071337] [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: 05/08/2023] [Revised: 06/15/2023] [Accepted: 06/19/2023] [Indexed: 07/30/2023] Open
Abstract
Pseudomonas is a bacterial genus with some saprophytic species from land and others associated with opportunistic infections in humans and animals. Factors such as pathogenicity or metabolic aspects have been related to CRISPR-Cas, and in silico studies into it have focused more on the clinical and non-environmental setting. This work aimed to perform an in silico analysis of the CRISPR-Cas systems present in Pseudomonas genomes. It analyzed 275 complete genomic sequences of Pseudomonas taken from the NCBI database. CRISPR loci were obtained from CRISPRdb. The genes associated with CRISPR (cas) and CAS proteins, and the origin and diversity of spacer sequences, were identified and compared by BLAST. The presence of self-targeting sequences, PAMs, and the conservation of DRs were visualized using WebLogo 3.6. The CRISPR-like RNA secondary structure prediction was analyzed using RNAFold and MFold. CRISPR structures were identified in 19.6% of Pseudomonas species. In all, 113 typical CRISPR arrays with 18 putative cas were found, as were 2050 spacers, of which 52% showed homology to bacteriophages, 26% to chromosomes, and 22% to plasmids. No potential self-targeting was detected within the CRISPR array. All the found DRs can form thermodynamically stable secondary RNA structures. The comparison of the CRISPR/Cas system can help understand the environmental adaptability of each evolutionary lineage of clinically and environmentally relevant species, providing data support for bacterial typing, traceability, analysis, and exploration of unconventional CRISPR.
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Affiliation(s)
- Ángel Parra-Sánchez
- Genetics and Molecular Biology Laboratory, Biology Department, Faculty of Sciences, University of Zulia, Maracaibo 4001, Venezuela
- Neuroprosthesis and Visual Rehabilitation Laboratory, Bioengineering Institute, University Miguel Hernández of Elche, 03202 Elche, Spain
| | - Laura Antequera-Zambrano
- Genetics and Molecular Biology Laboratory, Biology Department, Faculty of Sciences, University of Zulia, Maracaibo 4001, Venezuela
| | - Gema Martínez-Navarrete
- Neuroprosthesis and Visual Rehabilitation Laboratory, Bioengineering Institute, University Miguel Hernández of Elche, 03202 Elche, Spain
| | - Vanessa Zorrilla-Muñoz
- Bioengineering Institute, University Miguel Hernández of Elche, 03202 Elche, Spain
- University Institute on Gender Studies, University Carlos III of Madrid, Getafe, 28903 Madrid, Spain
| | - José Luis Paz
- Academic Department of Inorganic Chemistry, Faculty of Chemistry and Chemical Engineering, National University of San Marcos, Lima 15081, Peru
| | - Ysaias J Alvarado
- Laboratory of Theoretical and Experimental Biophysical Chemistry (LQBTE), Center for Molecular Biomedicine (CBM), Venezuelan Institute for Scientific Research (IVIC), Maracaibo 4001, Venezuela
| | - Lenin González-Paz
- Genetics and Molecular Biology Laboratory, Biology Department, Faculty of Sciences, University of Zulia, Maracaibo 4001, Venezuela
- Laboratory of Biocomputing (LB), Center for Molecular Biomedicine (CBM), Venezuelan Institute for Scientific Research (IVIC), Maracaibo 4001, Venezuela
| | - Eduardo Fernández
- Neuroprosthesis and Visual Rehabilitation Laboratory, Bioengineering Institute, University Miguel Hernández of Elche, 03202 Elche, Spain
- Biomedical Research Network Center (CIBER-BBN), 28029 Madrid, Spain
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3
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Padilha VA, Alkhnbashi OS, Tran VD, Shah SA, Carvalho ACPLF, Backofen R. Casboundary: automated definition of integral Cas cassettes. Bioinformatics 2021; 37:1352-1359. [PMID: 33226067 PMCID: PMC8208735 DOI: 10.1093/bioinformatics/btaa984] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/28/2020] [Accepted: 11/11/2020] [Indexed: 11/13/2022] Open
Abstract
MOTIVATION CRISPR-Cas are important systems found in most archaeal and many bacterial genomes, providing adaptive immunity against mobile genetic elements in prokaryotes. The CRISPR-Cas systems are encoded by a set of consecutive cas genes, here termed cassette. The identification of cassette boundaries is key for finding cassettes in CRISPR research field. This is often carried out by using Hidden Markov Models and manual annotation. In this article, we propose the first method able to automatically define the cassette boundaries. In addition, we present a Cas-type predictive model used by the method to assign each gene located in the region defined by a cassette's boundaries a Cas label from a set of pre-defined Cas types. Furthermore, the proposed method can detect potentially new cas genes and decompose a cassette into its modules. RESULTS We evaluate the predictive performance of our proposed method on data collected from the two most recent CRISPR classification studies. In our experiments, we obtain an average similarity of 0.86 between the predicted and expected cassettes. Besides, we achieve F-scores above 0.9 for the classification of cas genes of known types and 0.73 for the unknown ones. Finally, we conduct two additional study cases, where we investigate the occurrence of potentially new cas genes and the occurrence of module exchange between different genomes. AVAILABILITY AND IMPLEMENTATION https://github.com/BackofenLab/Casboundary. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Victor A Padilha
- Institute of Mathematics and Computer Sciences, University of São Paulo, São Carlos, SP 13566-590, Brazil
| | - Omer S Alkhnbashi
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany
| | - Van Dinh Tran
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany
| | - Shiraz A Shah
- COPSAC, Copenhagen University Hospitals Herlev and Gentofte, DK-2820 Gentofte, Denmark
| | - André C P L F Carvalho
- Institute of Mathematics and Computer Sciences, University of São Paulo, São Carlos, SP 13566-590, Brazil
| | - Rolf Backofen
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
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Abstract
In the ocean, viruses impact microbial mortality, regulate biogeochemical cycling, and alter the metabolic potential of microbial lineages. At deep-sea hydrothermal vents, abundant viruses infect a wide range of hosts among the archaea and bacteria that inhabit these dynamic habitats. However, little is known about viral diversity, host range, and biogeography across different vent ecosystems, which has important implications for how viruses manipulate microbial function and evolution. Here, we examined viral diversity, viral and host distribution, and virus-host interactions in microbial metagenomes generated from venting fluids from several vent sites within three different geochemically and geographically distinct hydrothermal systems: Piccard and Von Damm vent fields at the Mid-Cayman Rise in the Caribbean Sea, and at several vent sites within Axial Seamount in the Pacific Ocean. Analysis of viral sequences and clustered regularly interspaced short palindromic repeat (CRISPR) spacers revealed highly diverse viral assemblages and evidence of active infection. Network analysis revealed that viral host range was relatively narrow, with very few viruses infecting multiple microbial lineages. Viruses were largely endemic to individual vent sites, indicating restricted dispersal, and in some cases, viral assemblages persisted over time. Thus, we show that hydrothermal vent fluids are home to novel, diverse viral assemblages that are highly localized to specific regions and taxa. IMPORTANCE Viruses play important roles in manipulating microbial communities and their evolution in the ocean, yet not much is known about viruses in deep-sea hydrothermal vents. However, viral ecology and evolution are of particular interest in hydrothermal vent habitats because of their unique nature: previous studies have indicated that most viruses in hydrothermal vents are temperate rather than lytic, and it has been established that rates of horizontal gene transfer (HGT) are particularly high among thermophilic vent microbes, and viruses are common vectors for HGT. If viruses have broad host range or are widespread across vent sites, they have increased potential to act as gene-sharing "highways" between vent sites. By examining viral diversity, distribution, and infection networks across disparate vent sites, this study provides the opportunity to better characterize and constrain the viral impact on hydrothermal vent microbial communities. We show that viruses in hydrothermal vents are diverse and apparently active, but most have restricted host range and are not widely distributed among vent sites. Thus, the impacts of viral infection are likely to be highly localized and constrained to specific taxa in these habitats.
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5
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Abstract
CRISPR-Cas systems are immune systems that protect bacteria and archaea against their viruses, bacteriophages. Immunity is achieved through the acquisition of short DNA fragments from the viral invader’s genome. CRISPR-Cas immune systems adapt to new threats by acquiring new spacers from invading nucleic acids such as phage genomes. However, some CRISPR-Cas loci lack genes necessary for spacer acquisition despite variation in spacer content between microbial strains. It has been suggested that such loci may use acquisition machinery from cooccurring CRISPR-Cas systems within the same strain. Here, following infection by a virulent phage with a double-stranded DNA (dsDNA) genome, we observed spacer acquisition in the native host Flavobacterium columnare that carries an acquisition-deficient CRISPR-Cas subtype VI-B system and a complete subtype II-C system. We show that the VI-B locus acquires spacers from both the bacterial and phage genomes, while the newly acquired II-C spacers mainly target the viral genome. Both loci preferably target the terminal end of the phage genome, with priming-like patterns around a preexisting II-C protospacer. Through gene deletion, we show that the RNA-cleaving VI-B system acquires spacers in trans using acquisition machinery from the DNA-cleaving II-C system. Our observations support the concept of cross talk between CRISPR-Cas systems and raise further questions regarding the plasticity of adaptation modules.
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6
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Shmakov SA, Utkina I, Wolf YI, Makarova KS, Severinov KV, Koonin EV. CRISPR Arrays Away from cas Genes. CRISPR J 2020; 3:535-549. [PMID: 33346707 PMCID: PMC7757702 DOI: 10.1089/crispr.2020.0062] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
CRISPR-Cas systems typically consist of a CRISPR array and cas genes that are organized in one or more operons. However, a substantial fraction of CRISPR arrays are not adjacent to cas genes. Definitive identification of such isolated CRISPR arrays runs into the problem of false-positives, with unrelated types of repetitive sequences mimicking CRISPR. We developed a computational pipeline to eliminate false CRISPR predictions and found that up to 25% of the CRISPR arrays in complete bacterial and archaeal genomes are located away from cas genes. Most of the repeats in these isolated arrays are identical to repeats in cas-adjacent CRISPR arrays in the same or closely related genomes, indicating an evolutionary relationship between isolated arrays and arrays in typical CRISPR-cas loci. The spacers in isolated CRISPR arrays show nearly as many matches to viral genomes as spacers from complete CRISPR-cas loci, suggesting that the isolated arrays were either functionally active recently or continue to function. Reconstruction of evolutionary events in closely related bacterial genomes suggests three routes of evolution of isolated CRISPR arrays: (1) loss of cas genes in a CRISPR-cas locus, (2) de novo generation of arrays from off-target spacer integration into sequences resembling the corresponding repeats, and (3) transfer by mobile genetic elements. Both combination of de novo emerging arrays with cas genes and regain of cas genes by isolated arrays via recombination likely contribute to functional diversification in CRISPR-Cas evolution.
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Affiliation(s)
- Sergey A. Shmakov
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA; Rutgers, State University of New Jersey, Piscataway, New Jersey, USA
| | - Irina Utkina
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA; Rutgers, State University of New Jersey, Piscataway, New Jersey, USA
- Skolkovo Institute of Science and Technology, Skolkovo, Russia; Rutgers, State University of New Jersey, Piscataway, New Jersey, USA
- The Hospital for Sick Children, University of Toronto, Toronto, Canada; Rutgers, State University of New Jersey, Piscataway, New Jersey, USA
| | - Yuri I. Wolf
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA; Rutgers, State University of New Jersey, Piscataway, New Jersey, USA
| | - Kira S. Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA; Rutgers, State University of New Jersey, Piscataway, New Jersey, USA
| | - Konstantin V. Severinov
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia; and Rutgers, State University of New Jersey, Piscataway, New Jersey, USA
- Waksman Institute of Microbiology, Rutgers, State University of New Jersey, Piscataway, New Jersey, USA
| | - Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA; Rutgers, State University of New Jersey, Piscataway, New Jersey, USA
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7
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CRISPR-Cas adaptive immune systems in Sulfolobales: genetic studies and molecular mechanisms. SCIENCE CHINA-LIFE SCIENCES 2020; 64:678-696. [DOI: 10.1007/s11427-020-1745-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 05/25/2020] [Indexed: 12/26/2022]
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8
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Hafer-Hahmann N, Vorburger C. Parasitoids as drivers of symbiont diversity in an insect host. Ecol Lett 2020; 23:1232-1241. [PMID: 32375203 DOI: 10.1111/ele.13526] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/25/2020] [Accepted: 04/08/2020] [Indexed: 01/01/2023]
Abstract
Immune systems have repeatedly diversified in response to parasite diversity. Many animals have outsourced part of their immune defence to defensive symbionts, which should be affected by similar evolutionary pressures as the host's own immune system. Protective symbionts provide efficient and specific protection and respond to changing selection pressure by parasites. Here we use the aphid Aphis fabae, its protective symbiont Hamiltonella defensa, and its parasitoid Lysiphlebus fabarum to test whether parasite diversity can maintain diversity in protective symbionts. We exposed aphid populations with the same initial symbiont composition to parasitoid populations that differed in their diversity. As expected, single parasitoid genotypes mostly favoured a single symbiont that was most protective against that particular parasitoid, while multiple symbionts persisted in aphids exposed to more diverse parasitoid populations, which in turn affected aphid population density and rates of parasitism. Parasite diversity may be crucial to maintaining symbiont diversity in nature.
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Affiliation(s)
- Nina Hafer-Hahmann
- EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, Switzerland
| | - Christoph Vorburger
- EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Überlandstrasse 133, 8600 Dübendorf, Switzerland.,Institute of Integrative Biology, ETH Zürich, Universitätsstrasse 16, 8092 Zürich, Switzerland
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9
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Abstract
CRISPR-Cas, the bacterial and archaeal adaptive immunity systems, encompass a complex machinery that integrates fragments of foreign nucleic acids, mostly from mobile genetic elements (MGE), into CRISPR arrays embedded in microbial genomes. Transcripts of the inserted segments (spacers) are employed by CRISPR-Cas systems as guide (g)RNAs for recognition and inactivation of the cognate targets. The CRISPR-Cas systems consist of distinct adaptation and effector modules whose evolutionary trajectories appear to be at least partially independent. Comparative genome analysis reveals the origin of the adaptation module from casposons, a distinct type of transposons, which employ a homologue of Cas1 protein, the integrase responsible for the spacer incorporation into CRISPR arrays, as the transposase. The origin of the effector module(s) is far less clear. The CRISPR-Cas systems are partitioned into two classes, class 1 with multisubunit effectors, and class 2 in which the effector consists of a single, large protein. The class 2 effectors originate from nucleases encoded by different MGE, whereas the origin of the class 1 effector complexes remains murky. However, the recent discovery of a signalling pathway built into the type III systems of class 1 might offer a clue, suggesting that type III effector modules could have evolved from a signal transduction system involved in stress-induced programmed cell death. The subsequent evolution of the class 1 effector complexes through serial gene duplication and displacement, primarily of genes for proteins containing RNA recognition motif domains, can be hypothetically reconstructed. In addition to the multiple contributions of MGE to the evolution of CRISPR-Cas, the reverse flow of information is notable, namely, recruitment of minimalist variants of CRISPR-Cas systems by MGE for functions that remain to be elucidated. Here, we attempt a synthesis of the diverse threads that shed light on CRISPR-Cas origins and evolution. This article is part of a discussion meeting issue 'The ecology and evolution of prokaryotic CRISPR-Cas adaptive immune systems'.
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Affiliation(s)
- Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine , Bethesda, MD 20894 , USA
| | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine , Bethesda, MD 20894 , USA
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10
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Pinilla-Redondo R, Mayo-Muñoz D, Russel J, Garrett RA, Randau L, Sørensen SJ, Shah SA. Type IV CRISPR-Cas systems are highly diverse and involved in competition between plasmids. Nucleic Acids Res 2020; 48:2000-2012. [PMID: 31879772 PMCID: PMC7038947 DOI: 10.1093/nar/gkz1197] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/02/2019] [Accepted: 12/13/2019] [Indexed: 12/18/2022] Open
Abstract
CRISPR-Cas systems provide prokaryotes with adaptive immune functions against viruses and other genetic parasites. In contrast to all other types of CRISPR-Cas systems, type IV has remained largely overlooked. Here, we describe a previously uncharted diversity of type IV gene cassettes, primarily encoded by plasmid-like elements from diverse prokaryotic taxa. Remarkably, via a comprehensive analysis of their CRISPR spacer content, these systems were found to exhibit a strong bias towards the targeting of other plasmids. Our data indicate that the functions of type IV systems have diverged from those of other host-related CRISPR-Cas immune systems to adopt a role in mediating conflicts between plasmids. Furthermore, we find evidence for cross-talk between certain type IV and type I CRISPR-Cas systems that co-exist intracellularly, thus providing a simple answer to the enigmatic absence of type IV adaptation modules. Collectively, our results lead to the expansion and reclassification of type IV systems and provide novel insights into the biological function and evolution of these elusive systems.
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Affiliation(s)
- Rafael Pinilla-Redondo
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
- Department of Technological Educations, University College Copenhagen, Sigurdsgade 26, 2200 Copenhagen, Denmark
| | - David Mayo-Muñoz
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Jakob Russel
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Roger A Garrett
- Danish Archaea Centre, Department of Biology, University of Copenhagen, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark
| | - Lennart Randau
- Philipps-Universität Marburg, Faculty of Biology, Hans-Meerwein-Straße 6, 35032 Marburg, Germany
| | - Søren J Sørensen
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Shiraz A Shah
- Copenhagen Prospective Studies on Asthma in Childhood (COPSAC), Herlev and Gentofte Hospital, University of Copenhagen, Ledreborg Alle 34, 2820 Gentofte, Denmark
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11
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Alkhnbashi OS, Meier T, Mitrofanov A, Backofen R, Voß B. CRISPR-Cas bioinformatics. Methods 2020; 172:3-11. [PMID: 31326596 DOI: 10.1016/j.ymeth.2019.07.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 06/19/2019] [Accepted: 07/15/2019] [Indexed: 02/07/2023] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and their associated proteins (Cas) are essential genetic elements in many archaeal and bacterial genomes, playing a key role in a prokaryote adaptive immune system against invasive foreign elements. In recent years, the CRISPR-Cas system has also been engineered to facilitate target gene editing in eukaryotic genomes. Bioinformatics played an essential role in the detection and analysis of CRISPR systems and here we review the bioinformatics-based efforts that pushed the field of CRISPR-Cas research further. We discuss the bioinformatics tools that have been published over the last few years and, finally, present the most popular tools for the design of CRISPR-Cas9 guides.
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Affiliation(s)
| | - Tobias Meier
- Computational Biology, Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany.
| | | | - Rolf Backofen
- Chair of Bioinformatics, University of Freiburg, Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Germany.
| | - Björn Voß
- Computational Biology, Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany.
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12
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Makarova KS, Wolf YI, Iranzo J, Shmakov SA, Alkhnbashi OS, Brouns SJJ, Charpentier E, Cheng D, Haft DH, Horvath P, Moineau S, Mojica FJM, Scott D, Shah SA, Siksnys V, Terns MP, Venclovas Č, White MF, Yakunin AF, Yan W, Zhang F, Garrett RA, Backofen R, van der Oost J, Barrangou R, Koonin EV. Evolutionary classification of CRISPR–Cas systems: a burst of class 2 and derived variants. Nat Rev Microbiol 2019; 18:67-83. [DOI: 10.1038/s41579-019-0299-x] [Citation(s) in RCA: 797] [Impact Index Per Article: 159.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2019] [Indexed: 12/16/2022]
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13
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Milicevic O, Repac J, Bozic B, Djordjevic M, Djordjevic M. A Simple Criterion for Inferring CRISPR Array Direction. Front Microbiol 2019; 10:2054. [PMID: 31551987 PMCID: PMC6737040 DOI: 10.3389/fmicb.2019.02054] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 08/20/2019] [Indexed: 12/14/2022] Open
Abstract
Inferring transcriptional direction (orientation) of the CRISPR array is essential for many applications, including systematically investigating non-canonical CRISPR/Cas functions. The standard method, CRISPRDirection (embedded within CRISPRCasFinder), fails to predict the orientation (ND predictions) for ∼37% of the classified CRISPR arrays (>2200 loci); this goes up to >70% for the II-B subtype where non-canonical functions were first experimentally discovered. Alternatively, Potential Orientation (also embedded within CRISPRCasFinder), has a much smaller frequency of ND predictions but might have significantly lower accuracy. We propose a novel simple criterion, where the CRISPR array direction is assigned according to the direction of its associated cas genes (Cas Orientation). We systematically assess the performance of the three methods (Cas Orientation, CRISPRDirection, and Potential Orientation) across all CRISPR/Cas subtypes, by a mutual crosscheck of their predictions, and by comparing them to the experimental dataset. Interestingly, CRISPRDirection agrees much better with Cas Orientation than with Potential Orientation, despite CRISPRDirection and Potential Orientation being mutually related – Potential Orientation corresponding to one of six (heterogeneous) predictors employed by CRISPRDirection – and being unrelated to Cas Orientation. We find that Cas Orientation has much higher accuracy compared to Potential Orientation and comparable accuracy to CRISPRDirection – while accurately assigning an orientation to ∼95% of the CRISPR arrays that are non-determined by CRISPRDirection. Cas Orientation is, at the same time, simple to employ, requiring only (routine for prokaryotes) the prediction of the associated protein coding gene direction.
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Affiliation(s)
- Ognjen Milicevic
- School of Medicine, University of Belgrade, Belgrade, Serbia.,Multidisciplinary Ph.D. Program in Biophysics, University of Belgrade, Belgrade, Serbia
| | - Jelena Repac
- Faculty of Biology, Institute of Physiology and Biochemistry, University of Belgrade, Belgrade, Serbia
| | - Bojan Bozic
- Faculty of Biology, Institute of Physiology and Biochemistry, University of Belgrade, Belgrade, Serbia
| | | | - Marko Djordjevic
- Faculty of Biology, Institute of Physiology and Biochemistry, University of Belgrade, Belgrade, Serbia
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14
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Scholz I, Lott SC, Behler J, Gärtner K, Hagemann M, Hess WR. Divergent methylation of CRISPR repeats and cas genes in a subtype I-D CRISPR-Cas-system. BMC Microbiol 2019; 19:147. [PMID: 31262257 PMCID: PMC6604393 DOI: 10.1186/s12866-019-1526-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 06/20/2019] [Indexed: 02/07/2023] Open
Abstract
Background The presence and activity of CRISPR-Cas defense systems is a hallmark of many prokaryotic microorganisms. Here, the distribution of sequences related to the highly iterated palindrome 1 (HIP1) element and the DNA methylation of CGATCG motifs embedded within HIP1 as a vital part of the CRISPR1 repeat sequence was analyzed in the cyanobacterium Synechocystis sp. PCC 6803. Previously suggested functions of HIP1 include organization of chromosomal structure, DNA recombination or gene regulation, all of which could be relevant in CRISPR-Cas functionality. Results The CRISPR1 repeat-spacer array contains more than 50 CGATCG elements that are double-methylated (5mCG6mATCG) by the enzymes M.Ssp6803I and M.Ssp6803III. Hence, more than 200 possible methylation events cluster over a stretch of 3600 bp of double-stranded DNA. Bisulfite sequencing showed that these motifs were highly methylated at the m5CGATCG positions whereas specific motifs within the CRISPR1 cas genes were hypomethylated suggesting a lowered accessibility for the DNA methylase to these regions. Assays for conjugation and CRISPR1-mediated DNA interference revealed a 50% drop in conjugation efficiency in the mutant lacking the 5mC methylation of CGATCG motifs, while the highly efficient DNA interference activity was not affected by the lack of m5CGATCG DNA-methylation, nor was the capability to differentiate between self and non-self targets based on the protospacer adjacent motifs (PAMs) GTA and GTC versus the non-PAM AGC. A third DNA methylation mediated by M.Ssp6803II modifies the first cytosine in the motif GGCC yielding GGm4CC. We found a remarkable absence of GGCC motifs and hence the corresponding methylation over an 11 kb stretch encompassing all the cas genes involved in interference and crRNA maturation but not adaptation of the CRISPR1 system. Conclusions The lack of GGCC tetranucleotides along the CRISPR1 interference and maturation genes supports the reported hybrid character of subtype I-D CRISPR-Cas systems. We report tight and very high 5mC methylation of the CRISPR1 repeat sequences. Nevertheless, cells lacking the 5mC methylation activity were unaffected in their CRISPR1-mediated interference response but the efficiency of conjugation was reduced by 50%. These results point to an unknown role of m5CGATCG DNA-methylation marks in conjugation and DNA transformation.
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Affiliation(s)
- Ingeborg Scholz
- Faculty of Biology, Genetics an Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, D-79104, Freiburg, Germany
| | - Steffen C Lott
- Faculty of Biology, Genetics an Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, D-79104, Freiburg, Germany
| | - Juliane Behler
- Faculty of Biology, Genetics an Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, D-79104, Freiburg, Germany
| | - Katrin Gärtner
- University of Rostock, Institute of Biosciences, Plant Physiology, A.-Einstein-Str. 3, D-18059, Rostock, Germany
| | - Martin Hagemann
- University of Rostock, Institute of Biosciences, Plant Physiology, A.-Einstein-Str. 3, D-18059, Rostock, Germany
| | - Wolfgang R Hess
- Faculty of Biology, Genetics an Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, D-79104, Freiburg, Germany. .,University of Freiburg, Freiburg Institute for Advanced Studies, Albertstr. 19, D-79104, Freiburg, Germany.
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15
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Nasko DJ, Ferrell BD, Moore RM, Bhavsar JD, Polson SW, Wommack KE. CRISPR Spacers Indicate Preferential Matching of Specific Virioplankton Genes. mBio 2019; 10:e02651-18. [PMID: 30837341 PMCID: PMC6401485 DOI: 10.1128/mbio.02651-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 12/14/2018] [Indexed: 01/21/2023] Open
Abstract
Viral infection exerts selection pressure on marine microbes, as virus-induced cell lysis causes 20 to 50% of cell mortality, resulting in fluxes of biomass into oceanic dissolved organic matter. Archaeal and bacterial populations can defend against viral infection using the clustered regularly interspaced short palindromic repeat (CRISPR)-associated (Cas) system, which relies on specific matching between a spacer sequence and a viral gene. If a CRISPR spacer match to any gene within a viral genome is equally effective in preventing lysis, no viral genes should be preferentially matched by CRISPR spacers. However, if there are differences in effectiveness, certain viral genes may demonstrate a greater frequency of CRISPR spacer matches. Indeed, homology search analyses of bacterioplankton CRISPR spacer sequences against virioplankton sequences revealed preferential matching of replication proteins, nucleic acid binding proteins, and viral structural proteins. Positive selection pressure for effective viral defense is one parsimonious explanation for these observations. CRISPR spacers from virioplankton metagenomes preferentially matched methyltransferase and phage integrase genes within virioplankton sequences. These virioplankton CRISPR spacers may assist infected host cells in defending against competing phage. Analyses also revealed that half of the spacer-matched viral genes were unknown, some genes matched several spacers, and some spacers matched multiple genes, a many-to-many relationship. Thus, CRISPR spacer matching may be an evolutionary algorithm, agnostically identifying those genes under stringent selection pressure for sustaining viral infection and lysis. Investigating this subset of viral genes could reveal those genetic mechanisms essential to virus-host interactions and provide new technologies for optimizing CRISPR defense in beneficial microbes.IMPORTANCE The CRISPR-Cas system is one means by which bacterial and archaeal populations defend against viral infection which causes 20 to 50% of cell mortality in the ocean. We tested the hypothesis that certain viral genes are preferentially targeted for the initial attack of the CRISPR-Cas system on a viral genome. Using CASC, a pipeline for CRISPR spacer discovery, and metagenome data from oceanic microbes and viruses, we found a clear subset of viral genes with high match frequencies to CRISPR spacers. Moreover, we observed a many-to-many relationship of spacers and viral genes. These high-match viral genes were involved in nucleotide metabolism, DNA methylation, and viral structure. It is possible that CRISPR spacer matching is an evolutionary algorithm pointing to those viral genes most important to sustaining infection and lysis. Studying these genes may advance the understanding of virus-host interactions in nature and provide new technologies for leveraging CRISPR-Cas systems in beneficial microbes.
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Affiliation(s)
- Daniel J Nasko
- Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, USA
| | - Barbra D Ferrell
- Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, USA
| | - Ryan M Moore
- Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, USA
| | - Jaysheel D Bhavsar
- Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, USA
| | - Shawn W Polson
- Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, USA
| | - K Eric Wommack
- Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, USA
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16
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Mayo-Muñoz D, He F, Jørgensen JB, Madsen PK, Bhoobalan-Chitty Y, Peng X. Anti-CRISPR-Based and CRISPR-Based Genome Editing of Sulfolobus islandicus Rod-Shaped Virus 2. Viruses 2018; 10:E695. [PMID: 30544778 PMCID: PMC6315595 DOI: 10.3390/v10120695] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/05/2018] [Accepted: 12/06/2018] [Indexed: 12/14/2022] Open
Abstract
Genetic engineering of viruses has generally been challenging. This is also true for archaeal rod-shaped viruses, which carry linear double-stranded DNA genomes with hairpin ends. In this paper, we describe two different genome editing approaches to mutate the Sulfolobus islandicus rod-shaped virus 2 (SIRV2) using the archaeon Sulfolobus islandicus LAL14/1 and its derivatives as hosts. The anti-CRISPR (Acr) gene acrID1, which inhibits CRISPR-Cas subtype I-D immunity, was first used as a selection marker to knock out genes from SIRV2M, an acrID1-null mutant of SIRV2. Moreover, we harnessed the endogenous CRISPR-Cas systems of the host to knock out the accessory genes consecutively, which resulted in a genome comprised solely of core genes of the 11 SIRV members. Furthermore, infection of this series of knockout mutants in the CRISPR-null host of LAL14/1 (Δarrays) confirmed the non-essentiality of the deleted genes and all except the last deletion mutant propagated as efficiently as the WT SIRV2. This suggested that the last gene deleted, SIRV2 gp37, is important for the efficient viral propagation. The generated viral mutants will be useful for future functional studies including searching for new Acrs and the approaches described in this case are applicable to other viruses.
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Affiliation(s)
- David Mayo-Muñoz
- Danish Archaea Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark.
| | - Fei He
- Danish Archaea Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark.
| | - Jacob Bruun Jørgensen
- Danish Archaea Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark.
| | - Poul Kári Madsen
- Danish Archaea Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark.
| | - Yuvaraj Bhoobalan-Chitty
- Danish Archaea Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark.
| | - Xu Peng
- Danish Archaea Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark.
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17
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Hou S, Brenes-Álvarez M, Reimann V, Alkhnbashi OS, Backofen R, Muro-Pastor AM, Hess WR. CRISPR-Cas systems in multicellular cyanobacteria. RNA Biol 2018; 16:518-529. [PMID: 29995583 DOI: 10.1080/15476286.2018.1493330] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Novel CRISPR-Cas systems possess substantial potential for genome editing and manipulation of gene expression. The types and numbers of CRISPR-Cas systems vary substantially between different organisms. Some filamentous cyanobacteria harbor > 40 different putative CRISPR repeat-spacer cassettes, while the number of cas gene instances is much lower. Here we addressed the types and diversity of CRISPR-Cas systems and of CRISPR-like repeat-spacer arrays in 171 publicly available genomes of multicellular cyanobacteria. The number of 1328 repeat-spacer arrays exceeded the total of 391 encoded Cas1 proteins suggesting a tendency for fragmentation or the involvement of alternative adaptation factors. The model cyanobacterium Anabaena sp. PCC 7120 contains only three cas1 genes but hosts three Class 1, possibly one Class 2 and five orphan repeat-spacer arrays, all of which exhibit crRNA-typical expression patterns suggesting active transcription, maturation and incorporation into CRISPR complexes. The CRISPR-Cas system within the element interrupting the Anabaena sp. PCC 7120 fdxN gene, as well as analogous arrangements in other strains, occupy the genetic elements that become excised during the differentiation-related programmed site-specific recombination. This fact indicates the propensity of these elements for the integration of CRISPR-cas systems and points to a previously not recognized connection. The gene all3613 resembling a possible Class 2 effector protein is linked to a short repeat-spacer array and a single tRNA gene, similar to its homologs in other cyanobacteria. The diversity and presence of numerous CRISPR-Cas systems in DNA elements that are programmed for homologous recombination make filamentous cyanobacteria a prolific resource for their study. Abbreviations: Cas: CRISPR associated sequences; CRISPR: Clustered Regularly Interspaced Short Palindromic Repeats; C2c: Class 2 candidate; SDR: small dispersed repeat; TSS: transcriptional start site; UTR: untranslated region.
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Affiliation(s)
- Shengwei Hou
- a Faculty of Biology, Genetics and Experimental Bioinformatics , University of Freiburg , Freiburg , Germany
| | - Manuel Brenes-Álvarez
- b Instituto de Bioquímica Vegetal y Fotosíntesis , Consejo Superior de Investigaciones Científicas and Universidad de Sevilla , Seville , Spain
| | - Viktoria Reimann
- a Faculty of Biology, Genetics and Experimental Bioinformatics , University of Freiburg , Freiburg , Germany
| | - Omer S Alkhnbashi
- c Bioinformatics group, Department of Computer Science , University of Freiburg , Freiburg , Germany
| | - Rolf Backofen
- c Bioinformatics group, Department of Computer Science , University of Freiburg , Freiburg , Germany.,d Center for Biological Systems Analysis (ZBSA) , University of Freiburg , Freiburg , Germany.,e BIOSS Centre for Biological Signaling Studies , University of Freiburg , Freiburg , Germany
| | - Alicia M Muro-Pastor
- c Bioinformatics group, Department of Computer Science , University of Freiburg , Freiburg , Germany
| | - Wolfgang R Hess
- a Faculty of Biology, Genetics and Experimental Bioinformatics , University of Freiburg , Freiburg , Germany.,f Freiburg Institute for Advanced Studies,University of Freiburg, Freiburg, Germany
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18
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Abstract
CRISPR-Cas systems are a highly effective immune mechanism for prokaryotes, providing defense against invading foreign DNA. By definition, all CRISPR-Cas systems have short repeats interspersing their spacers. These repeats play a key role in preventing cleavage of self DNA and in the integration of new spacers. Here we focus on the phenomenon of repeat modularity, namely the unexpectedly high degree of repeat conservation across different systems within a genome or between different species. We hypothesize that modularity can be beneficial for CRISPR-Cas containing organisms, because it facilitates horizontal acquisition of 'pre-immunized' CRISPR arrays and allows the utilization of spacers acquired by one system for use by other systems within the same cell.
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Affiliation(s)
- Yael Yair
- a School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences , Tel Aviv University , Tel Aviv , Israel
| | - Uri Gophna
- a School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences , Tel Aviv University , Tel Aviv , Israel
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19
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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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20
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Ishino Y, Krupovic M, Forterre P. History of CRISPR-Cas from Encounter with a Mysterious Repeated Sequence to Genome Editing Technology. J Bacteriol 2018; 200:e00580-17. [PMID: 29358495 PMCID: PMC5847661 DOI: 10.1128/jb.00580-17] [Citation(s) in RCA: 196] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Clustered regularly interspaced short palindromic repeat (CRISPR)-Cas systems are well-known acquired immunity systems that are widespread in archaea and bacteria. The RNA-guided nucleases from CRISPR-Cas systems are currently regarded as the most reliable tools for genome editing and engineering. The first hint of their existence came in 1987, when an unusual repetitive DNA sequence, which subsequently was defined as a CRISPR, was discovered in the Escherichia coli genome during an analysis of genes involved in phosphate metabolism. Similar sequence patterns were then reported in a range of other bacteria as well as in halophilic archaea, suggesting an important role for such evolutionarily conserved clusters of repeated sequences. A critical step toward functional characterization of the CRISPR-Cas systems was the recognition of a link between CRISPRs and the associated Cas proteins, which were initially hypothesized to be involved in DNA repair in hyperthermophilic archaea. Comparative genomics, structural biology, and advanced biochemistry could then work hand in hand, not only culminating in the explosion of genome editing tools based on CRISPR-Cas9 and other class II CRISPR-Cas systems but also providing insights into the origin and evolution of this system from mobile genetic elements denoted casposons. To celebrate the 30th anniversary of the discovery of CRISPR, this minireview briefly discusses the fascinating history of CRISPR-Cas systems, from the original observation of an enigmatic sequence in E. coli to genome editing in humans.
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Affiliation(s)
- Yoshizumi Ishino
- Unité de Biologie Moléculaire du Gène Chez les Extrêmophiles, Département de Microbiologie, Institut Pasteur, Paris, France
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan
| | - Mart Krupovic
- Unité de Biologie Moléculaire du Gène Chez les Extrêmophiles, Département de Microbiologie, Institut Pasteur, Paris, France
| | - Patrick Forterre
- Unité de Biologie Moléculaire du Gène Chez les Extrêmophiles, Département de Microbiologie, Institut Pasteur, Paris, France
- Institute of Integrative Cellular Biology, Université Paris Sud, Orsay, France
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21
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McCluskey K, Carlos Penedo J. An integrated perspective on RNA aptamer ligand-recognition models: clearing muddy waters. Phys Chem Chem Phys 2018; 19:6921-6932. [PMID: 28225108 DOI: 10.1039/c6cp08798a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Riboswitches are short RNA motifs that sensitively and selectively bind cognate ligands to modulate gene expression. Like protein receptor-ligand pairs, their binding dynamics are traditionally categorized as following one of two paradigmatic mechanisms: conformational selection and induced fit. In conformational selection, ligand binding stabilizes a particular state already present in the receptor's dynamic ensemble. In induced fit, ligand-receptor interactions enable the system to overcome the energetic barrier into a previously inaccessible state. In this article, we question whether a polarized division of RNA binding mechanisms truly meets the conceptual needs of the field. We will review the history behind this classification of RNA-ligand interactions, and the way induced fit in particular has been rehabilitated by single-molecule studies of RNA aptamers. We will highlight several recent results from single-molecule experimental studies of riboswitches that reveal gaps or even contradictions between common definitions of the two terms, and we will conclude by proposing a more robust framework that considers the range of RNA behaviors unveiled in recent years as a reality to be described, rather than an increasingly unwieldy set of exceptions to the traditional models.
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Affiliation(s)
- K McCluskey
- Department of Physics and Astronomy, University of St. Andrews, St. Andrews, KY16 9SS, UK.
| | - J Carlos Penedo
- Department of Physics and Astronomy, University of St. Andrews, St. Andrews, KY16 9SS, UK. and Biomolecular Sciences Research Complex, University of St. Andrews, St. Andrews, KY16 9SS, UK.
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22
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He F, Vestergaard G, Peng W, She Q, Peng X. CRISPR-Cas type I-A Cascade complex couples viral infection surveillance to host transcriptional regulation in the dependence of Csa3b. Nucleic Acids Res 2017; 45:1902-1913. [PMID: 27980065 PMCID: PMC5389559 DOI: 10.1093/nar/gkw1265] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 12/07/2016] [Indexed: 12/25/2022] Open
Abstract
CRISPR-Cas (clustered regularly interspaced short palindromic repeats and the associated genes) constitute adaptive immune systems in bacteria and archaea and they provide sequence specific immunity against foreign nucleic acids. CRISPR-Cas systems are activated by viral infection. However, little is known about how CRISPR-Cas systems are activated in response to viral infection or how their expression is controlled in the absence of viral infection. Here, we demonstrate that both the transcriptional regulator Csa3b, and the type I-A interference complex Cascade, are required to transcriptionally repress the interference gene cassette in the archaeon Sulfolobus. Csa3b binds to two palindromic repeat sites in the promoter region of the cassette and facilitates binding of the Cascade to the promoter region. Upon viral infection, loading of Cascade complexes onto crRNA-matching protospacers leads to relief of the transcriptional repression. Our data demonstrate a mechanism coupling CRISPR-Cas surveillance of protospacers to transcriptional regulation of the interference gene cassette thereby allowing a fast response to viral infection.
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Affiliation(s)
- Fei He
- Archaea Centre, Department of Biology, Copenhagen University, DK2200 Copenhagen N, Denmark
| | - Gisle Vestergaard
- Helmholtz Zentrum München, Research Unit Environmental Genomics, Ingolstädter Landstraße 1, 85764 Oberschleißheim, Germany
| | - Wenfang Peng
- Archaea Centre, Department of Biology, Copenhagen University, DK2200 Copenhagen N, Denmark
| | - Qunxin She
- Archaea Centre, Department of Biology, Copenhagen University, DK2200 Copenhagen N, Denmark
| | - Xu Peng
- Archaea Centre, Department of Biology, Copenhagen University, DK2200 Copenhagen N, Denmark
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23
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Alkhnbashi OS, Shah SA, Garrett RA, Saunders SJ, Costa F, Backofen R. Characterizing leader sequences of CRISPR loci. Bioinformatics 2017; 32:i576-i585. [PMID: 27587677 DOI: 10.1093/bioinformatics/btw454] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
MOTIVATION The CRISPR-Cas system is an adaptive immune system in many archaea and bacteria, which provides resistance against invading genetic elements. The first phase of CRISPR-Cas immunity is called adaptation, in which small DNA fragments are excised from genetic elements and are inserted into a CRISPR array generally adjacent to its so called leader sequence at one end of the array. It has been shown that transcription initiation and adaptation signals of the CRISPR array are located within the leader. However, apart from promoters, there is very little knowledge of sequence or structural motifs or their possible functions. Leader properties have mainly been characterized through transcriptional initiation data from single organisms but large-scale characterization of leaders has remained challenging due to their low level of sequence conservation. RESULTS We developed a method to successfully detect leader sequences by focusing on the consensus repeat of the adjacent CRISPR array and weak upstream conservation signals. We applied our tool to the analysis of a comprehensive genomic database and identified several characteristic properties of leader sequences specific to archaea and bacteria, ranging from distinctive sizes to preferential indel localization. CRISPRleader provides a full annotation of the CRISPR array, its strand orientation as well as conserved core leader boundaries that can be uploaded to any genome browser. In addition, it outputs reader-friendly HTML pages for conserved leader clusters from our database. AVAILABILITY AND IMPLEMENTATION CRISPRleader and multiple sequence alignments for all 195 leader clusters are available at http://www.bioinf.uni-freiburg.de/Software/CRISPRleader/ CONTACT costa@informatik.uni-freiburg.de or backofen@informatik.uni-freiburg.de SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Omer S Alkhnbashi
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany
| | - Shiraz A Shah
- Archaea Centre, Department of Biology, University of Copenhagen N, DK2200 Copenhagen N, Denmark
| | - Roger A Garrett
- Archaea Centre, Department of Biology, University of Copenhagen N, DK2200 Copenhagen N, Denmark
| | - Sita J Saunders
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany
| | - Fabrizio Costa
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany
| | - Rolf Backofen
- Bioinformatics Group, Department of Computer Science, University of Freiburg, 79110 Freiburg, Germany BIOSS Centre for Biological Signalling Studies, Cluster of Excellence, University of Freiburg, Freiburg im Breisgau, Germany
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24
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Moller AG, Liang C. Determining virus-host interactions and glycerol metabolism profiles in geographically diverse solar salterns with metagenomics. PeerJ 2017; 5:e2844. [PMID: 28097058 PMCID: PMC5228507 DOI: 10.7717/peerj.2844] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 11/29/2016] [Indexed: 01/12/2023] Open
Abstract
Solar salterns are excellent model ecosystems for studying virus-microbial interactions because of their low microbial diversity, environmental stability, and high viral density. By using the power of CRISPR spacers to link viruses to their prokaryotic hosts, we explored virus-host interactions in geographically diverse salterns. Using taxonomic profiling, we identified hosts such as archaeal Haloquadratum, Halorubrum, and Haloarcula and bacterial Salinibacter, and we found that community composition related to not only salinity but also local environmental dynamics. Characterizing glycerol metabolism genes in these metagenomes suggested Halorubrum and Haloquadratum possess most dihydroxyacetone kinase genes while Salinibacter possesses most glycerol-3-phosphate dehydrogenase genes. Using two different methods, we detected fewer CRISPR spacers in Haloquadratum-dominated compared with Halobacteriaceae-dominated saltern metagenomes. After CRISPR detection, spacers were aligned against haloviral genomes to map virus to host. While most alignments for each saltern metagenome linked viruses to Haloquadratum walsbyi, there were also alignments indicating interactions with the low abundance taxa Haloarcula and Haloferax. Further examination of the dinucleotide and trinucleotide usage differences between paired viruses and their hosts confirmed viruses and hosts had similar nucleotide usage signatures. Detection of cas genes in the salterns supported the possibility of CRISPR activity. Taken together, our studies suggest similar virus-host interactions exist in different solar salterns and that the glycerol metabolism gene dihydroxyacetone kinase is associated with Haloquadratum and Halorubrum.
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Affiliation(s)
| | - Chun Liang
- Department of Biology, Miami University, Oxford, OH, United States
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25
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Elmore JR, Sheppard NF, Ramia N, Deighan T, Li H, Terns RM, Terns MP. Bipartite recognition of target RNAs activates DNA cleavage by the Type III-B CRISPR-Cas system. Genes Dev 2016; 30:447-59. [PMID: 26848045 PMCID: PMC4762429 DOI: 10.1101/gad.272153.115] [Citation(s) in RCA: 170] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/03/2015] [Indexed: 12/18/2022]
Abstract
Here, Elmore et al. investigate how the Type III-B Cmr complex, which cleaves invader RNAs recognized by the CRISPR RNA (crRNA), functions. The findings demonstrate that the Cmr complex is a novel DNA nuclease activated by invader RNAs containing a crRNA target sequence and a protospacer-adjacent motif (rPAM). CRISPR–Cas systems eliminate nucleic acid invaders in bacteria and archaea. The effector complex of the Type III-B Cmr system cleaves invader RNAs recognized by the CRISPR RNA (crRNA ) of the complex. Here we show that invader RNAs also activate the Cmr complex to cleave DNA. As has been observed for other Type III systems, Cmr eliminates plasmid invaders in Pyrococcus furiosus by a mechanism that depends on transcription of the crRNA target sequence within the plasmid. Notably, we found that the target RNA per se induces DNA cleavage by the Cmr complex in vitro. DNA cleavage activity does not depend on cleavage of the target RNA but notably does require the presence of a short sequence adjacent to the target sequence within the activating target RNA (rPAM [RNA protospacer-adjacent motif]). The activated complex does not require a target sequence (or a PAM) in the DNA substrate. Plasmid elimination by the P. furiosus Cmr system also does not require the Csx1 (CRISPR-associated Rossman fold [CARF] superfamily) protein. Plasmid silencing depends on the HD nuclease and Palm domains of the Cmr2 (Cas10 superfamily) protein. The results establish the Cmr complex as a novel DNA nuclease activated by invader RNAs containing a crRNA target sequence and a rPAM.
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Affiliation(s)
- Joshua R Elmore
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Nolan F Sheppard
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Nancy Ramia
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32313, USA
| | - Trace Deighan
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Hong Li
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32313, USA
| | - Rebecca M Terns
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Michael P Terns
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA; Department of Genetics, Florida State University, Tallahassee, Florida 32313, USA; Department of Microbiology, University of Georgia, Athens, Georgia 30602, USA
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Sheppard NF, Glover CVC, Terns RM, Terns MP. The CRISPR-associated Csx1 protein of Pyrococcus furiosus is an adenosine-specific endoribonuclease. RNA (NEW YORK, N.Y.) 2016; 22:216-24. [PMID: 26647461 PMCID: PMC4712672 DOI: 10.1261/rna.039842.113] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 10/27/2015] [Indexed: 05/15/2023]
Abstract
Prokaryotes are frequently exposed to potentially harmful invasive nucleic acids from phages, plasmids, and transposons. One method of defense is the CRISPR-Cas adaptive immune system. Diverse CRISPR-Cas systems form distinct ribonucleoprotein effector complexes that target and cleave invasive nucleic acids to provide immunity. The Type III-B Cmr effector complex has been found to target the RNA and DNA of the invader in the various bacterial and archaeal organisms where it has been characterized. Interestingly, the gene encoding the Csx1 protein is frequently located in close proximity to the Cmr1-6 genes in many genomes, implicating a role for Csx1 in Cmr function. However, evidence suggests that Csx1 is not a stably associated component of the Cmr effector complex, but is necessary for DNA silencing by the Cmr system in Sulfolobus islandicus. To investigate the function of the Csx1 protein, we characterized the activity of recombinant Pyrococcus furiosus Csx1 against various nucleic acid substrates. We show that Csx1 is a metal-independent, endoribonuclease that acts selectively on single-stranded RNA and cleaves specifically after adenosines. The RNA cleavage activity of Csx1 is dependent upon a conserved HEPN motif located within the C-terminal domain of the protein. This motif is also key for activity in other known ribonucleases. Collectively, the findings indicate that invader silencing by Type III-B CRISPR-Cas systems relies both on RNA and DNA nuclease activities from the Cmr effector complex as well as on the affiliated, trans-acting Csx1 endoribonuclease.
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Affiliation(s)
- Nolan F Sheppard
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Claiborne V C Glover
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Rebecca M Terns
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Michael P Terns
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA Department of Genetics, University of Georgia, Athens, Georgia 30602, USA Department of Microbiology, University of Georgia, Athens, Georgia 30602, USA
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27
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León-Sobrino C, Kot WP, Garrett RA. Transcriptome changes in STSV2-infected Sulfolobus islandicus REY15A undergoing continuous CRISPR spacer acquisition. Mol Microbiol 2015; 99:719-28. [PMID: 26514343 DOI: 10.1111/mmi.13263] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/28/2015] [Indexed: 12/21/2022]
Abstract
A transcriptome study was performed on Sulfolobus islandicus REY15A actively undergoing CRISPR spacer acquisition from the crenarchaeal monocaudavirus STSV2 in rich and basal media over a 6 day period. Spacer acquisition preceded strong host growth retardation, altered transcriptional activity of four different CRISPR-Cas modules and changes in viral copy numbers, and with significant differences in the two media. Transcript levels of proteins involved in the cell cycle were reduced, whereas those of DNA replication, DNA repair, transcriptional regulation and some antitoxin-toxin pairs and transposases were unchanged or enhanced. Antisense RNAs were implicated in the transcriptional regulation of adaptation and interference modules of the type I-A CRISPR-Cas system, and evidence was found for the occurrence of functional co-ordination between the single CRISPR-Cas adaptation module and the functionally diverse interference modules.
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Affiliation(s)
- Carlos León-Sobrino
- Archaea Centre, Department of Biology, University of Copenhagen, Copenhagen, DK-2200, Denmark
| | - Witold P Kot
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - Roger A Garrett
- Archaea Centre, Department of Biology, University of Copenhagen, Copenhagen, DK-2200, Denmark
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28
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An updated evolutionary classification of CRISPR-Cas systems. NATURE REVIEWS. MICROBIOLOGY 2015. [PMID: 26411297 DOI: 10.1038/nrmicro3569.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The evolution of CRISPR-cas loci, which encode adaptive immune systems in archaea and bacteria, involves rapid changes, in particular numerous rearrangements of the locus architecture and horizontal transfer of complete loci or individual modules. These dynamics complicate straightforward phylogenetic classification, but here we present an approach combining the analysis of signature protein families and features of the architecture of cas loci that unambiguously partitions most CRISPR-cas loci into distinct classes, types and subtypes. The new classification retains the overall structure of the previous version but is expanded to now encompass two classes, five types and 16 subtypes. The relative stability of the classification suggests that the most prevalent variants of CRISPR-Cas systems are already known. However, the existence of rare, currently unclassifiable variants implies that additional types and subtypes remain to be characterized.
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29
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Makarova KS, Wolf YI, Alkhnbashi OS, Costa F, Shah SA, Saunders SJ, Barrangou R, Brouns SJJ, Charpentier E, Haft DH, Horvath P, Moineau S, Mojica FJM, Terns RM, Terns MP, White MF, Yakunin AF, Garrett RA, van der Oost J, Backofen R, Koonin EV. An updated evolutionary classification of CRISPR-Cas systems. Nat Rev Microbiol 2015; 13:722-36. [PMID: 26411297 DOI: 10.1038/nrmicro3569] [Citation(s) in RCA: 1553] [Impact Index Per Article: 172.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The evolution of CRISPR-cas loci, which encode adaptive immune systems in archaea and bacteria, involves rapid changes, in particular numerous rearrangements of the locus architecture and horizontal transfer of complete loci or individual modules. These dynamics complicate straightforward phylogenetic classification, but here we present an approach combining the analysis of signature protein families and features of the architecture of cas loci that unambiguously partitions most CRISPR-cas loci into distinct classes, types and subtypes. The new classification retains the overall structure of the previous version but is expanded to now encompass two classes, five types and 16 subtypes. The relative stability of the classification suggests that the most prevalent variants of CRISPR-Cas systems are already known. However, the existence of rare, currently unclassifiable variants implies that additional types and subtypes remain to be characterized.
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Affiliation(s)
- Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Omer S Alkhnbashi
- Bioinformatics group, Department of Computer Science, University of Freiberg, Georges-Kohler-Allee 106, 79110 Freiberg, Germany
| | - Fabrizio Costa
- Bioinformatics group, Department of Computer Science, University of Freiberg, Georges-Kohler-Allee 106, 79110 Freiberg, Germany
| | - Shiraz A Shah
- Archaea Centre, Department of Biology, Copenhagen University, Ole Maaløes Vej 5, DK2200 Copenhagen N, Denmark
| | - Sita J Saunders
- Bioinformatics group, Department of Computer Science, University of Freiberg, Georges-Kohler-Allee 106, 79110 Freiberg, Germany
| | - Rodolphe Barrangou
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina 27606, USA
| | - Stan J J Brouns
- Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703HB Wageningen, Netherlands
| | - Emmanuelle Charpentier
- Department of Regulation in Infection Biology, Helmholtz Centre for Infection Research, D-38124 Braunschweig, Germany
| | - Daniel H Haft
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Philippe Horvath
- DuPont Nutrition and Health, BP10, Dangé-Saint-Romain 86220, France
| | - Sylvain Moineau
- Département de Biochimie, de Microbiologie et de Bio-informatique, Faculté des Sciences et de Génie, Groupe de Recherche en Écologie Buccale, Félix d'Hérelle Reference Center for Bacterial Viruses, Faculté de médecine dentaire, Université Laval, Québec City, Québec, Canada
| | - Francisco J M Mojica
- Departamento de Fisiología, Genética y Microbiología. Universidad de Alicante. 03080-Alicante, Spain
| | - Rebecca M Terns
- Biochemistry and Molecular Biology, Genetics and Microbiology, University of Georgia, Davison Life Sciences Complex, Green Street, Athens, Georgia 30602, USA
| | - Michael P Terns
- Biochemistry and Molecular Biology, Genetics and Microbiology, University of Georgia, Davison Life Sciences Complex, Green Street, Athens, Georgia 30602, USA
| | - Malcolm F White
- Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, KY16 9TZ, UK
| | - Alexander F Yakunin
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, M5S 3E5, Canada
| | - Roger A Garrett
- Archaea Centre, Department of Biology, Copenhagen University, Ole Maaløes Vej 5, DK2200 Copenhagen N, Denmark
| | - John van der Oost
- Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703HB Wageningen, Netherlands
| | - Rolf Backofen
- Bioinformatics group, Department of Computer Science, University of Freiberg, Georges-Kohler-Allee 106, 79110 Freiberg, Germany.,BIOSS Centre for Biological Signaling Studies, Cluster of Excellence, University of Freiburg, Germany
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
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Abstract
SUMMARY Research on archaeal extrachromosomal genetic elements (ECEs) has progressed rapidly in the past decade. To date, over 60 archaeal viruses and 60 plasmids have been isolated. These archaeal viruses exhibit an exceptional diversity in morphology, with a wide array of shapes, such as spindles, rods, filaments, spheres, head-tails, bottles, and droplets, and some of these new viruses have been classified into one order, 10 families, and 16 genera. Investigation of model archaeal viruses has yielded important insights into mechanisms underlining various steps in the viral life cycle, including infection, DNA replication and transcription, and virion egression. Many of these mechanisms are unprecedented for any known bacterial or eukaryal viruses. Studies of plasmids isolated from different archaeal hosts have also revealed a striking diversity in gene content and innovation in replication strategies. Highly divergent replication proteins are identified in both viral and plasmid genomes. Genomic studies of archaeal ECEs have revealed a modular sequence structure in which modules of DNA sequence are exchangeable within, as well as among, plasmid families and probably also between viruses and plasmids. In particular, it has been suggested that ECE-host interactions have shaped the coevolution of ECEs and their archaeal hosts. Furthermore, archaeal hosts have developed defense systems, including the innate restriction-modification (R-M) system and the adaptive CRISPR (clustered regularly interspaced short palindromic repeats) system, to restrict invasive plasmids and viruses. Together, these interactions permit a delicate balance between ECEs and their hosts, which is vitally important for maintaining an innovative gene reservoir carried by ECEs. In conclusion, while research on archaeal ECEs has just started to unravel the molecular biology of these genetic entities and their interactions with archaeal hosts, it is expected to accelerate in the next decade.
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Tschitschko B, Williams TJ, Allen MA, Páez-Espino D, Kyrpides N, Zhong L, Raftery MJ, Cavicchioli R. Antarctic archaea-virus interactions: metaproteome-led analysis of invasion, evasion and adaptation. ISME JOURNAL 2015; 9:2094-107. [PMID: 26125682 DOI: 10.1038/ismej.2015.110] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 04/15/2015] [Accepted: 05/19/2015] [Indexed: 01/21/2023]
Abstract
Despite knowledge that viruses are abundant in natural ecosystems, there is limited understanding of which viruses infect which hosts, and how both hosts and viruses respond to those interactions-interactions that ultimately shape community structure and dynamics. In Deep Lake, Antarctica, intergenera gene exchange occurs rampantly within the low complexity, haloarchaea-dominated community, strongly balanced by distinctions in niche adaptation which maintain sympatric speciation. By performing metaproteomics for the first time on haloarchaea, genomic variation of S-layer, archaella and other cell surface proteins was linked to mechanisms of infection evasion. CRISPR defense systems were found to be active, with haloarchaea responding to at least eight distinct types of viruses, including those infecting between genera. The role of BREX systems in defending against viruses was also examined. Although evasion and defense were evident, both hosts and viruses also may benefit from viruses carrying and expressing host genes, thereby potentially enhancing genetic variation and phenotypic differences within populations. The data point to a complex inter-play leading to a dynamic optimization of host-virus interactions. This comprehensive overview was achieved only through the integration of results from metaproteomics, genomics and metagenomics.
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Affiliation(s)
- Bernhard Tschitschko
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | - Timothy J Williams
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | - Michelle A Allen
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | | | - Nikos Kyrpides
- Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Ling Zhong
- Bioanalytical Mass Spectrometry Facility, The University of New South Wales, Sydney, New South Wales, Australia
| | - Mark J Raftery
- Bioanalytical Mass Spectrometry Facility, The University of New South Wales, Sydney, New South Wales, Australia
| | - Ricardo Cavicchioli
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia
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32
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When Competing Viruses Unify: Evolution, Conservation, and Plasticity of Genetic Identities. J Mol Evol 2015; 80:305-18. [PMID: 26014757 DOI: 10.1007/s00239-015-9683-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 05/12/2015] [Indexed: 02/06/2023]
Abstract
In the early 1970s, Manfred Eigen and colleagues developed the quasispecies model (qs) for the population-based origin of RNAs representing the early genetic code. The Eigen idea is basically that a halo of mutants is generated by error-prone replication around the master fittest type which will behave similarly as a biological population. But almost from the start, very interesting and unexpected observations were made regarding competition versus co-operation which suggested more complex interactions. It thus became increasingly clear that although viruses functioned similar to biological species, their behavior was much more complex than the original theory could explain, especially adaptation without changing the consensus involving minority populations. With respect to the origin of natural codes, meaning, and code-use in interactions (communication), it also became clear that individual fittest type-based mechanisms were likewise unable to explain the origin of natural codes such as the genetic code with their context- and consortia-dependence (pragmatic nature). This, instead, required the participation of groups of agents competent in the code and able to edit code because natural codes do not code themselves. Three lines of inquiry, experimental virology, quasispecies theory, and the study of natural codes converged to indicate that consortia of co-operative RNA agents such as viruses must be involved in the fitness of RNA and its involvement in communication, i.e., code-competent interactions. We called this co-operative form quasispecies consortia (qs-c). They are the essential agents that constitute the possibility of evolution of biological group identity. Finally, the basic interactional motifs for the emergence of group identity, communication, and co-operation-together with its opposing functions-are explained by the "Gangen" hypothesis.
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Garrett RA, Shah SA, Erdmann S, Liu G, Mousaei M, León-Sobrino C, Peng W, Gudbergsdottir S, Deng L, Vestergaard G, Peng X, She Q. CRISPR-Cas Adaptive Immune Systems of the Sulfolobales: Unravelling Their Complexity and Diversity. Life (Basel) 2015; 5:783-817. [PMID: 25764276 PMCID: PMC4390879 DOI: 10.3390/life5010783] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 02/24/2015] [Accepted: 02/27/2015] [Indexed: 12/26/2022] Open
Abstract
The Sulfolobales have provided good model organisms for studying CRISPR-Cas systems of the crenarchaeal kingdom of the archaea. These organisms are infected by a wide range of exceptional archaea-specific viruses and conjugative plasmids, and their CRISPR-Cas systems generally exhibit extensive structural and functional diversity. They carry large and multiple CRISPR loci and often multiple copies of diverse Type I and Type III interference modules as well as more homogeneous adaptation modules. These acidothermophilic organisms have recently provided seminal insights into both the adaptation process, the diverse modes of interference, and their modes of regulation. The functions of the adaptation and interference modules tend to be loosely coupled and the stringency of the crRNA-DNA sequence matching during DNA interference is relatively low, in contrast to some more streamlined CRISPR-Cas systems of bacteria. Despite this, there is evidence for a complex and differential regulation of expression of the diverse functional modules in response to viral infection. Recent work also supports critical roles for non-core Cas proteins, especially during Type III-directed interference, and this is consistent with these proteins tending to coevolve with core Cas proteins. Various novel aspects of CRISPR-Cas systems of the Sulfolobales are considered including an alternative spacer acquisition mechanism, reversible spacer acquisition, the formation and significance of antisense CRISPR RNAs, and a novel mechanism for avoidance of CRISPR-Cas defense. Finally, questions regarding the basis for the complexity, diversity, and apparent redundancy, of the intracellular CRISPR-Cas systems are discussed.
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Affiliation(s)
- Roger A Garrett
- Archaea Centre, Department of Biology, Copenhagen University, Ole Maaløes Vej 5, DK2200 Copenhagen N, Denmark.
| | - Shiraz A Shah
- Archaea Centre, Department of Biology, Copenhagen University, Ole Maaløes Vej 5, DK2200 Copenhagen N, Denmark.
| | - Susanne Erdmann
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, 2052 Sydney NSW, Australia.
| | - Guannan Liu
- Archaea Centre, Department of Biology, Copenhagen University, Ole Maaløes Vej 5, DK2200 Copenhagen N, Denmark.
| | - Marzieh Mousaei
- Archaea Centre, Department of Biology, Copenhagen University, Ole Maaløes Vej 5, DK2200 Copenhagen N, Denmark.
| | - Carlos León-Sobrino
- Archaea Centre, Department of Biology, Copenhagen University, Ole Maaløes Vej 5, DK2200 Copenhagen N, Denmark.
| | - Wenfang Peng
- Archaea Centre, Department of Biology, Copenhagen University, Ole Maaløes Vej 5, DK2200 Copenhagen N, Denmark.
| | - Soley Gudbergsdottir
- Archaea Centre, Department of Biology, Copenhagen University, Ole Maaløes Vej 5, DK2200 Copenhagen N, Denmark.
| | - Ling Deng
- Archaea Centre, Department of Biology, Copenhagen University, Ole Maaløes Vej 5, DK2200 Copenhagen N, Denmark.
| | - Gisle Vestergaard
- Helmholtz Zentrum München, Research Unit Environmental Genomics, Ingolstädter Landstraße 1, 85764 Oberschleißheim, Germany.
| | - Xu Peng
- Archaea Centre, Department of Biology, Copenhagen University, Ole Maaløes Vej 5, DK2200 Copenhagen N, Denmark.
| | - Qunxin She
- Archaea Centre, Department of Biology, Copenhagen University, Ole Maaløes Vej 5, DK2200 Copenhagen N, Denmark.
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Liu T, Li Y, Wang X, Ye Q, Li H, Liang Y, She Q, Peng N. Transcriptional regulator-mediated activation of adaptation genes triggers CRISPR de novo spacer acquisition. Nucleic Acids Res 2015; 43:1044-55. [PMID: 25567986 PMCID: PMC4333418 DOI: 10.1093/nar/gku1383] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Acquisition of de novo spacer sequences confers CRISPR-Cas with a memory to defend against invading genetic elements. However, the mechanism of regulation of CRISPR spacer acquisition remains unknown. Here we examine the transcriptional regulation of the conserved spacer acquisition genes in Type I-A of Sulfolobus islandicus REY15A. Csa3a, a MarR-like transcription factor encoded by the gene located adjacent to csa1, cas1, cas2 and cas4 cluster, but on the reverse strand, was demonstrated to specifically bind to the csa1 and cas1 promoters with the imperfect palindromic sequence. Importantly, it was demonstrated that the transcription level of csa1, cas1, cas2 and cas4 was significantly enhanced in a csa3a-overexpression strain and, moreover, the Csa1 and Cas1 protein levels were increased in this strain. Furthermore, we demonstrated the hyperactive uptake of unique spacers within both CRISPR loci in the presence of the csa3a overexpression vector. The spacer acquisition process is dependent on the CCN PAM sequence and protospacer selection is random and non-directional. These results suggested a regulation mechanism of CRISPR spacer acquisition where a single transcriptional regulator senses the presence of an invading element and then activates spacer acquisition gene expression which leads to de novo spacer uptake from the invading element.
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Affiliation(s)
- Tao Liu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Yingjun Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Xiaodi Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Qing Ye
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Huan Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China
| | - Yunxiang Liang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China Hubei Collaborative Innovation Center for Industrial Fermentation, Wuhan 430070, P. R. China
| | - Qunxin She
- Archaeal Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Nan Peng
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, P. R. China Hubei Collaborative Innovation Center for Industrial Fermentation, Wuhan 430070, P. R. China
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35
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Erdmann S, Garrett RA. Archaeal Viruses of the Sulfolobales: Isolation, Infection, and CRISPR Spacer Acquisition. Methods Mol Biol 2015; 1311:223-32. [PMID: 25981476 DOI: 10.1007/978-1-4939-2687-9_14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Infection of archaea with phylogenetically diverse single viruses, performed in different laboratories, has failed to activate spacer acquisition into host CRISPR loci. The first successful uptake of archaeal de novo spacers was observed on infection of Sulfolobus solfataricus P2 with an environmental virus mixture isolated from Yellowstone National Park (Erdmann and Garrett, Mol Microbiol 85:1044-1056, 2012). Experimental studies of isolated genetic elements from this mixture revealed that SMV1 (S ulfolobus Monocauda Virus 1), a tailed spindle-shaped virus, can induce spacer acquisition in CRISPR loci of Sulfolobus species from a second coinfecting conjugative plasmid or virus (Erdmann and Garrett, Mol Microbiol 85:1044-1056, 2012; Erdmann et al. Mol Microbiol 91:900-917, 2014). Here we describe, firstly, the isolation of archaeal virus mixtures from terrestrial hot springs and the techniques used both to infect laboratory strains with these virus mixtures and to obtain purified virus particles. Secondly, we present the experimental conditions required for activating SMV1-induced spacer acquisition in two different Sulfolobus species.
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Affiliation(s)
- Susanne Erdmann
- Archaea Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen N, Denmark,
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36
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Hale CR, Cocozaki A, Li H, Terns RM, Terns MP. Target RNA capture and cleavage by the Cmr type III-B CRISPR-Cas effector complex. Genes Dev 2014; 28:2432-43. [PMID: 25367038 PMCID: PMC4215187 DOI: 10.1101/gad.250712.114] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The effector complex of the Cmr/type III-B CRISPR–Cas system cleaves RNAs recognized by the crRNA of the complex and includes six protein subunits of unknown functions. Hale et al. used reconstituted Pyrococcus furiosus Cmr complexes and found that Cmr3 recognizes the signature crRNA tag sequence (and depends on protein–protein interactions with Cmr2, Cmr4, and Cmr5), each Cmr4 subunit mediates a target RNA cleavage, and Cmr1 and Cmr6 mediate an essential interaction between the 3′ region of the crRNA and the target RNA. The effector complex of the Cmr/type III-B CRISPR (clustered regularly interspaced short palindromic repeat)–Cas (CRISPR-associated) system cleaves RNAs recognized by the CRISPR RNA (crRNA) of the complex and includes six protein subunits of unknown functions. Using reconstituted Pyrococcus furiosus Cmr complexes, we found that each of the six Cmr proteins plays a critical role in either crRNA interaction or target RNA capture. Cmr2, Cmr3, Cmr4, and Cmr5 are all required for formation of a crRNA-containing complex detected by native gel electrophoresis, and the conserved 5′ repeat sequence tag and 5′-OH group of the crRNA are essential for the interaction. Interestingly, capture of the complementary target RNA additionally requires both Cmr1 and Cmr6. In detailed functional studies, we determined that P. furiosus Cmr complexes cleave target RNAs at 6-nucleotide (nt) intervals in the region of complementarity, beginning 5 nt downstream from the crRNA tag and continuing to within ∼14 nt of the 3′ end of the crRNA. Our findings indicate that Cmr3 recognizes the signature crRNA tag sequence (and depends on protein–protein interactions with Cmr2, Cmr4, and Cmr5), each Cmr4 subunit mediates a target RNA cleavage, and Cmr1 and Cmr6 mediate an essential interaction between the 3′ region of the crRNA and the target RNA.
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Affiliation(s)
- Caryn R Hale
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA
| | - Alexis Cocozaki
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306, USA
| | - Hong Li
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida 32306, USA; Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, USA
| | - Rebecca M Terns
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA;
| | - Michael P Terns
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA; Department of Genetics, Department of Microbiology, University of Georgia, Athens, Georgia 30602, USA
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37
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Luk AWS, Williams TJ, Erdmann S, Papke RT, Cavicchioli R. Viruses of haloarchaea. Life (Basel) 2014; 4:681-715. [PMID: 25402735 PMCID: PMC4284463 DOI: 10.3390/life4040681] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 10/23/2014] [Accepted: 10/24/2014] [Indexed: 12/26/2022] Open
Abstract
In hypersaline environments, haloarchaea (halophilic members of the Archaea) are the dominant organisms, and the viruses that infect them, haloarchaeoviruses are at least ten times more abundant. Since their discovery in 1974, described haloarchaeoviruses include head-tailed, pleomorphic, spherical and spindle-shaped morphologies, representing Myoviridae, Siphoviridae, Podoviridae, Pleolipoviridae, Sphaerolipoviridae and Fuselloviridae families. This review overviews current knowledge of haloarchaeoviruses, providing information about classification, morphotypes, macromolecules, life cycles, genetic manipulation and gene regulation, and host-virus responses. In so doing, the review incorporates knowledge from laboratory studies of isolated viruses, field-based studies of environmental samples, and both genomic and metagenomic analyses of haloarchaeoviruses. What emerges is that some haloarchaeoviruses possess unique morphological and life cycle properties, while others share features with other viruses (e.g., bacteriophages). Their interactions with hosts influence community structure and evolution of populations that exist in hypersaline environments as diverse as seawater evaporation ponds, to hot desert or Antarctic lakes. The discoveries of their wide-ranging and important roles in the ecology and evolution of hypersaline communities serves as a strong motivator for future investigations of both laboratory-model and environmental systems.
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Affiliation(s)
- Alison W S Luk
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia.
| | - Timothy J Williams
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia.
| | - Susanne Erdmann
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia.
| | - R Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269-3125, USA.
| | - Ricardo Cavicchioli
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia.
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38
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He F, Chen L, Peng X. First Experimental Evidence for the Presence of a CRISPR Toxin in Sulfolobus. J Mol Biol 2014; 426:3683-3688. [DOI: 10.1016/j.jmb.2014.09.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 09/16/2014] [Accepted: 09/24/2014] [Indexed: 10/24/2022]
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Maier LK, Fischer S, Stoll B, Brendel J, Pfeiffer F, Dyall-Smith M, Marchfelder A. The immune system of halophilic archaea. Mob Genet Elements 2014; 2:228-232. [PMID: 23446883 PMCID: PMC3575430 DOI: 10.4161/mge.22530] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Prokaryotes have developed several strategies to defend themselves against foreign genetic elements. One of those defense mechanisms is the recently identified CRISPR/Cas system, which is used by approximately half of all bacterial and almost all archaeal organisms. The CRISPR/Cas system differs from the other defense strategies because it is adaptive, hereditary and it recognizes the invader by a sequence specific mechanism. To identify the invading foreign nucleic acid, a crRNA that matches the invader DNA is required, as well as a short sequence motif called protospacer adjacent motif (PAM). We recently identified the PAM sequences for the halophilic archaeon Haloferax volcanii, and found that several motifs were active in triggering the defense reaction. In contrast, selection of protospacers from the invader seems to be based on fewer PAM sequences, as evidenced by comparative sequence data. This suggests that the selection of protospacers has stricter requirements than the defense reaction. Comparison of CRISPR-repeat sequences carried by sequenced haloarchaea revealed that in more than half of the species, the repeat sequence is conserved and that they have the same CRISPR/Cas type.
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40
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Wietz M, Millán-Aguiñaga N, Jensen PR. CRISPR-Cas systems in the marine actinomycete Salinispora: linkages with phage defense, microdiversity and biogeography. BMC Genomics 2014; 15:936. [PMID: 25344663 PMCID: PMC4223832 DOI: 10.1186/1471-2164-15-936] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 09/29/2014] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Prokaryotic CRISPR-Cas systems confer resistance to viral infection and thus mediate bacteria-phage interactions. However, the distribution and functional diversity of CRISPRs among environmental bacteria remains largely unknown. Here, comparative genomics of 75 Salinispora strains provided insight into the diversity and distribution of CRISPR-Cas systems in a cosmopolitan marine actinomycete genus. RESULTS CRISPRs were found in all Salinispora strains, with the majority containing multiple loci and different Cas array subtypes. Of the six subtypes identified, three have not been previously described. A lower prophage frequency in S. arenicola was associated with a higher fraction of spacers matching Salinispora prophages compared to S. tropica, suggesting differing defensive capacities between Salinispora species. The occurrence of related prophages in strains from distant locations, as well as spacers matching those prophages inserted throughout spacer arrays, indicate recurring encounters with widely distributed phages over time. Linkages of CRISPR features with Salinispora microdiversity pointed to subclade-specific contacts with mobile genetic elements (MGEs). This included lineage-specific spacer deletions or insertions, which may reflect weak selective pressures to maintain immunity or distinct temporal interactions with MGEs, respectively. Biogeographic patterns in spacer and prophage distributions support the concept that Salinispora spp. encounter localized MGEs. Moreover, the presence of spacers matching housekeeping genes suggests that CRISPRs may have functions outside of viral defense. CONCLUSIONS This study provides a comprehensive examination of CRISPR-Cas systems in a broadly distributed group of environmental bacteria. The ubiquity and diversity of CRISPRs in Salinispora suggests that CRISPR-mediated interactions with MGEs represent a major force in the ecology and evolution of this cosmopolitan marine actinomycete genus.
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Affiliation(s)
- Matthias Wietz
- />Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037 USA
- />Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, 26129 Oldenburg, Germany
| | - Natalie Millán-Aguiñaga
- />Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037 USA
| | - Paul R Jensen
- />Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037 USA
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41
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Requirements for a successful defence reaction by the CRISPR-Cas subtype I-B system. Biochem Soc Trans 2014; 41:1444-8. [PMID: 24256235 DOI: 10.1042/bst20130098] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Uptake of foreign mobile genetic elements is often detrimental and can result in cell death. For protection against invasion, prokaryotes have developed several defence mechanisms, which take effect at all stages of infection; an example is the recently discovered CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) immune system. This defence system directly degrades invading genetic material and is present in almost all archaea and many bacteria. Current data indicate a large variety of mechanistic molecular approaches. Although almost all archaea carry this defence weapon, only a few archaeal systems have been fully characterized. In the present paper, we summarize the prerequisites for the detection and degradation of invaders in the halophilic archaeon Haloferax volcanii. H. volcanii encodes a subtype I-B CRISPR-Cas system and the defence can be triggered by a plasmid-based invader. Six different target-interference motifs are recognized by the Haloferax defence and a 9-nt non-contiguous seed sequence is essential. The repeat sequence has the potential to fold into a minimal stem-loop structure, which is conserved in haloarchaea and might be recognized by the Cas6 endoribonuclease during the processing of CRISPR loci into mature crRNA (CRISPR RNA). Individual crRNA species were present in very different concentrations according to an RNA-Seq analysis and many were unable to trigger a successful defence reaction. Recognition of the plasmid invader does not depend on its copy number, but instead results indicate a dependency on the type of origin present on the plasmid.
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42
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SMV1 virus-induced CRISPR spacer acquisition from the conjugative plasmid pMGB1 in Sulfolobus solfataricus P2. Biochem Soc Trans 2014; 41:1449-58. [PMID: 24256236 PMCID: PMC3839810 DOI: 10.1042/bst20130196] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Organisms of the crenarchaeal order Sulfolobales carry complex CRISPR (clustered regularly interspaced short palindromic repeats) adaptive immune systems. These systems are modular and show extensive structural and functional diversity, especially in their interference complexes. The primary targets are an exceptional range of diverse viruses, many of which propagate stably within cells and follow lytic life cycles without producing cell lysis. These properties are consistent with the difficulty of activating CRISPR spacer uptake in the laboratory, but appear to conflict with the high complexity and diversity of the CRISPR immune systems that are found among the Sulfolobales. In the present article, we re-examine the first successful induction of archaeal spacer acquisition in our laboratory that occurred exclusively for the conjugative plasmid pMGB1 in Sulfolobus solfataricus P2 that was co-infected with the virus SMV1 (Sulfolobus monocaudavirus 1). Although we reaffirm that protospacer selection is essentially a random process with respect to the pMGB1 genome, we identified single spacer sequences specific for each of CRISPR loci C, D and E that, exceptionally, occurred in many sequenced clones. Moreover, the same sequence was reproducibly acquired for a given locus in independent experiments, consistent with it being the first protospacer to be selected. There was also a small protospacer bias (1.6:1) to the antisense strand of protein genes. In addition, new experiments demonstrated that spacer acquisition in the previously inactive CRISPR locus A could be induced on freeze–thawing of the infected cells, suggesting that environmental stress can facilitate activation. Coincidentally with spacer acquisition, a mobile OrfB element was deleted from pMGB1, suggesting that interplay can occur between spacer acquisition and transposition.
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43
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Witzany G. Pragmatic turn in biology: From biological molecules to genetic content operators. World J Biol Chem 2014; 5:279-285. [PMID: 25225596 PMCID: PMC4160522 DOI: 10.4331/wjbc.v5.i3.279] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 03/12/2014] [Accepted: 05/19/2014] [Indexed: 02/05/2023] Open
Abstract
Erwin Schrödinger‘s question “What is life?” received the answer for decades of “physics + chemistry”. The concepts of Alain Turing and John von Neumann introduced a third term: “information”. This led to the understanding of nucleic acid sequences as a natural code. Manfred Eigen adapted the concept of Hammings “sequence space”. Similar to Hilbert space, in which every ontological entity could be defined by an unequivocal point in a mathematical axiomatic system, in the abstract ”sequence space” concept each point represents a unique syntactic structure and the value of their separation represents their dissimilarity. In this concept molecular features of the genetic code evolve by means of self-organisation of matter. Biological selection determines the fittest types among varieties of replication errors of quasi-species. The quasi-species concept dominated evolution theory for many decades. In contrast to this, recent empirical data on the evolution of DNA and its forerunners, the RNA-world and viruses indicate cooperative agent-based interactions. Group behaviour of quasi-species consortia constitute de novo and arrange available genetic content for adaptational purposes within real-life contexts that determine epigenetic markings. This review focuses on some fundamental changes in biology, discarding its traditional status as a subdiscipline of physics and chemistry.
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44
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Shapiro JA. Epigenetic control of mobile DNA as an interface between experience and genome change. Front Genet 2014; 5:87. [PMID: 24795749 PMCID: PMC4007016 DOI: 10.3389/fgene.2014.00087] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 04/01/2014] [Indexed: 12/29/2022] Open
Abstract
Mobile DNA in the genome is subject to RNA-targeted epigenetic control. This control regulates the activity of transposons, retrotransposons and genomic proviruses. Many different life history experiences alter the activities of mobile DNA and the expression of genetic loci regulated by nearby insertions. The same experiences induce alterations in epigenetic formatting and lead to trans-generational modifications of genome expression and stability. These observations lead to the hypothesis that epigenetic formatting directed by non-coding RNA provides a molecular interface between life history events and genome alteration.
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Affiliation(s)
- James A. Shapiro
- Department of Biochemistry and Molecular Biology, University of ChicagoChicago, IL, USA
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45
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Diversity, evolution, and therapeutic applications of small RNAs in prokaryotic and eukaryotic immune systems. Phys Life Rev 2014; 11:113-34. [DOI: 10.1016/j.plrev.2013.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Accepted: 11/05/2013] [Indexed: 12/26/2022]
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46
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Abstract
CRISPR adaptive immune systems were analyzed for all available completed genomes of archaea, which included representatives of each of the main archaeal phyla. Initially, all proteins encoded within, and proximal to, CRISPR-cas loci were clustered and analyzed using a profile–profile approach. Then cas genes were assigned to gene cassettes and to functional modules for adaptation and interference. CRISPR systems were then classified primarily on the basis of their concatenated Cas protein sequences and gene synteny of the interference modules. With few exceptions, they could be assigned to the universal Type I or Type III systems. For Type I, subtypes I-A, I-B, and I-D dominate but the data support the division of subtype I-B into two subtypes, designated I-B and I-G. About 70% of the Type III systems fall into the universal subtypes III-A and III-B but the remainder, some of which are phyla-specific, diverge significantly in Cas protein sequences, and/or gene synteny, and they are classified separately. Furthermore, a few CRISPR systems that could not be assigned to Type I or Type III are categorized as variant systems. Criteria are presented for assigning newly sequenced archaeal CRISPR systems to the different subtypes. Several accessory proteins were identified that show a specific gene linkage, especially to Type III interference modules, and these may be cofunctional with the CRISPR systems. Evidence is presented for extensive exchange having occurred between adaptation and interference modules of different archaeal CRISPR systems, indicating the wide compatibility of the functionally diverse interference complexes with the relatively conserved adaptation modules.
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Affiliation(s)
- Gisle Vestergaard
- Archaea Centre; Department of Biology; University of Copenhagen; Copenhagen, Denmark; Molecular Microbial Ecology Group; Department of Biology; University of Copenhagen; Copenhagen, Denmark
| | - Roger A Garrett
- Archaea Centre; Department of Biology; University of Copenhagen; Copenhagen, Denmark
| | - Shiraz A Shah
- Archaea Centre; Department of Biology; University of Copenhagen; Copenhagen, Denmark
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Brendel J, Stoll B, Lange SJ, Sharma K, Lenz C, Stachler AE, Maier LK, Richter H, Nickel L, Schmitz RA, Randau L, Allers T, Urlaub H, Backofen R, Marchfelder A. A complex of Cas proteins 5, 6, and 7 is required for the biogenesis and stability of clustered regularly interspaced short palindromic repeats (crispr)-derived rnas (crrnas) in Haloferax volcanii. J Biol Chem 2014; 289:7164-7177. [PMID: 24459147 PMCID: PMC3945376 DOI: 10.1074/jbc.m113.508184] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR-Cas) system is a prokaryotic defense mechanism against foreign genetic elements. A plethora of CRISPR-Cas versions exist, with more than 40 different Cas protein families and several different molecular approaches to fight the invading DNA. One of the key players in the system is the CRISPR-derived RNA (crRNA), which directs the invader-degrading Cas protein complex to the invader. The CRISPR-Cas types I and III use the Cas6 protein to generate mature crRNAs. Here, we show that the Cas6 protein is necessary for crRNA production but that additional Cas proteins that form a CRISPR-associated complex for antiviral defense (Cascade)-like complex are needed for crRNA stability in the CRISPR-Cas type I-B system in Haloferax volcanii in vivo. Deletion of the cas6 gene results in the loss of mature crRNAs and interference. However, cells that have the complete cas gene cluster (cas1–8b) removed and are transformed with the cas6 gene are not able to produce and stably maintain mature crRNAs. crRNA production and stability is rescued only if cas5, -6, and -7 are present. Mutational analysis of the cas6 gene reveals three amino acids (His-41, Gly-256, and Gly-258) that are essential for pre-crRNA cleavage, whereas the mutation of two amino acids (Ser-115 and Ser-224) leads to an increase of crRNA amounts. This is the first systematic in vivo analysis of Cas6 protein variants. In addition, we show that the H. volcanii I-B system contains a Cascade-like complex with a Cas7, Cas5, and Cas6 core that protects the crRNA.
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Affiliation(s)
- Jutta Brendel
- Department of Biology II, Ulm University, 89069 Ulm, Germany
| | - Britta Stoll
- Department of Biology II, Ulm University, 89069 Ulm, Germany
| | - Sita J Lange
- Bioinformatics Group, Department of Computer Science, University of Freiburg, Georges-Köhler-Allee 106, 79110 Freiburg, Germany
| | - Kundan Sharma
- Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Christof Lenz
- Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany; Bioanalytics, Institute of Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany
| | | | | | - Hagen Richter
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, 35043 Marburg, Germany
| | - Lisa Nickel
- Institute for General Microbiology, Christian-Albrechts-Universität Kiel, 24118 Kiel, Germany
| | - Ruth A Schmitz
- Institute for General Microbiology, Christian-Albrechts-Universität Kiel, 24118 Kiel, Germany
| | - Lennart Randau
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, 35043 Marburg, Germany
| | - Thorsten Allers
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, United Kingdom
| | - Henning Urlaub
- Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany; Bioanalytics, Institute of Clinical Chemistry, University Medical Center Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany
| | - Rolf Backofen
- Bioinformatics Group, Department of Computer Science, University of Freiburg, Georges-Köhler-Allee 106, 79110 Freiburg, Germany; Centre for Biological Signalling Studies (BIOSS), Cluster of Excellence, University of Freiburg, 79110 Freiburg, Germany
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48
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Erdmann S, Le Moine Bauer S, Garrett RA. Inter-viral conflicts that exploit host CRISPR immune systems of Sulfolobus. Mol Microbiol 2014; 91:900-17. [PMID: 24433295 DOI: 10.1111/mmi.12503] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2013] [Indexed: 12/26/2022]
Abstract
Infection of Sulfolobus islandicus REY15A with mixtures of different Sulfolobus viruses, including STSV2, did not induce spacer acquisition by the host CRISPR immune system. However, coinfection with the tailed fusiform viruses SMV1 and STSV2 generated hyperactive spacer acquisition in both CRISPR loci, exclusively from STSV2, with the resultant loss of STSV2 but not SMV1. SMV1 was shown to activate adaptation while itself being resistant to CRISPR-mediated adaptation and DNA interference. Exceptionally, a single clone S-1 isolated from an SMV1 + STSV2-infected culture, that carried STSV2-specific spacers and had lost STSV2 but not SMV1, acquired spacers from SMV1. This effect was also reproducible on reinfecting wild-type host cells with a variant SMV1 isolated from the S-1 culture. The SMV1 variant lacked a virion protein ORF114 that was shown to bind DNA. This study also provided evidence for: (i) limits on the maximum sizes of CRISPR loci; (ii) spacer uptake strongly retarding growth of infected cultures; (iii) protospacer selection being essentially random and non-directional, and (iv) the reversible uptake of spacers from STSV2 and SMV1. A hypothesis is presented to explain the interactive conflicts between SMV1 and the host CRISPR immune system.
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Affiliation(s)
- Susanne Erdmann
- Archaea Centre, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 N, Copenhagen, Denmark
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49
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Sandoval-Espinola WJ, Makwana ST, Chinn MS, Thon MR, Azcárate-Peril MA, Bruno-Bárcena JM. Comparative phenotypic analysis and genome sequence of Clostridium beijerinckii SA-1, an offspring of NCIMB 8052. MICROBIOLOGY (READING, ENGLAND) 2013; 159:2558-2570. [PMID: 24068240 PMCID: PMC7336276 DOI: 10.1099/mic.0.069534-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 09/24/2013] [Indexed: 01/07/2023]
Abstract
Production of butanol by solventogenic clostridia is controlled through metabolic regulation of the carbon flow and limited by its toxic effects. To overcome cell sensitivity to solvents, stress-directed evolution methodology was used three decades ago on Clostridium beijerinckii NCIMB 8052 that spawned the SA-1 strain. Here, we evaluated SA-1 solventogenic capabilities when growing on a previously validated medium containing, as carbon- and energy-limiting substrates, sucrose and the products of its hydrolysis d-glucose and d-fructose and only d-fructose. Comparative small-scale batch fermentations with controlled pH (pH 6.5) showed that SA-1 is a solvent hyper-producing strain capable of generating up to 16.1 g l(-1) of butanol and 26.3 g l(-1) of total solvents, 62.3 % and 63 % more than NCIMB 8052, respectively. This corresponds to butanol and solvent yields of 0.3 and 0.49 g g(-1), respectively (63 % and 65 % increase compared with NCIMB 8052). SA-1 showed a deficiency in d-fructose transport as suggested by its 7 h generation time compared with 1 h for NCIMB 8052. To potentially correlate physiological behaviour with genetic mutations, the whole genome of SA-1 was sequenced using the Illumina GA IIx platform. PCR and Sanger sequencing were performed to analyse the putative variations. As a result, four errors were confirmed and validated in the reference genome of NCIMB 8052 and a total of 10 genetic polymorphisms in SA-1. The genetic polymorphisms included eight single nucleotide variants, one small deletion and one large insertion that it is an additional copy of the insertion sequence ISCb1. Two of the genetic polymorphisms, the serine threonine phosphatase cbs_4400 and the solute binding protein cbs_0769, may possibly explain some of the observed physiological behaviour, such as rerouting of the metabolic carbon flow, deregulation of the d-fructose phosphotransferase transport system and delayed sporulation.
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Affiliation(s)
| | - Satya T. Makwana
- Department of Microbiology, North Carolina State University, Raleigh, NC 27695-7615, USA
| | - Mari S. Chinn
- Department of Biological and Agricultural Engineering, North Carolina State University, Raleigh, NC 27695-7615, USA
| | - Michael R. Thon
- Centro Hispano-Luso de Investigaciones Agrarias (CIALE), Departamento de Microbiología y Genética, Universidad de Salamanca, Calle Del Duero 12, Villamayor 37185, Spain
| | - M. Andrea Azcárate-Peril
- Department of Cell Biology and Physiology, School of Medicine and Microbiome Core Facility, Center for Gastrointestinal Biology and Disease, University of North Carolina, Chapel Hill, NC 27599-7545, USA
| | - José M. Bruno-Bárcena
- Department of Microbiology, North Carolina State University, Raleigh, NC 27695-7615, USA
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50
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Abstract
To survive the constant invasions by foreign genetic elements, prokaryotes have evolved various defensive systems. Almost all sequenced archaea, and half of the analysed bacteria use the CRISPR (clustered regularly interspaced short palindromic repeats)/Cas (CRISPR-associated) system, a recently identified prokaryotic immune system that can fend off invading elements in a sequence-specific manner. Few archaeal CRISPR/Cas systems have been analysed so far, and the molecular details of many of the steps involved in adaptation and defence are yet to be understood. In the present paper, we summarize our current knowledge about the CRISPR/Cas system in Haloferax volcanii, an extremely halophilic archaeon that was isolated from the Dead Sea. H. volcanii encodes a type I-B CRISPR/Cas system, and carries three CRISPR loci and eight Cas proteins. Although in laboratory culture for more than three decades, this defence system was shown to be still active. All three CRISPR loci are transcribed and processed into mature crRNAs (CRISPR RNAs). Cells challenged with engineered plasmids can recognize and eliminate these invading elements if they contain the correct PAM (protospacer adjacent motif) and a sequence that can be recognized by one of the CRISPR spacers.
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