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Classification and evolution of type II CRISPR-Cas systems

The CRISPR-Cas systems of archaeal and bacterial adaptive immunity are classified into three types that differ by the repertoires of CRISPR-associated (cas) genes, the organization of cas operons and the structure of repeats in the CRISPR arrays. The simplest among the CRISPR-Cas systems is type II...

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Autores principales: Chylinski, Krzysztof, Makarova, Kira S., Charpentier, Emmanuelle, Koonin, Eugene V.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4041416/
https://www.ncbi.nlm.nih.gov/pubmed/24728998
http://dx.doi.org/10.1093/nar/gku241
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author Chylinski, Krzysztof
Makarova, Kira S.
Charpentier, Emmanuelle
Koonin, Eugene V.
author_facet Chylinski, Krzysztof
Makarova, Kira S.
Charpentier, Emmanuelle
Koonin, Eugene V.
author_sort Chylinski, Krzysztof
collection PubMed
description The CRISPR-Cas systems of archaeal and bacterial adaptive immunity are classified into three types that differ by the repertoires of CRISPR-associated (cas) genes, the organization of cas operons and the structure of repeats in the CRISPR arrays. The simplest among the CRISPR-Cas systems is type II in which the endonuclease activities required for the interference with foreign deoxyribonucleic acid (DNA) are concentrated in a single multidomain protein, Cas9, and are guided by a co-processed dual-tracrRNA:crRNA molecule. This compact enzymatic machinery and readily programmable site-specific DNA targeting make type II systems top candidates for a new generation of powerful tools for genomic engineering. Here we report an updated census of CRISPR-Cas systems in bacterial and archaeal genomes. Type II systems are the rarest, missing in archaea, and represented in ∼5% of bacterial genomes, with an over-representation among pathogens and commensals. Phylogenomic analysis suggests that at least three cas genes, cas1, cas2 and cas4, and the CRISPR repeats of the type II-B system were acquired via recombination with a type I CRISPR-Cas locus. Distant homologs of Cas9 were identified among proteins encoded by diverse transposons, suggesting that type II CRISPR-Cas evolved via recombination of mobile nuclease genes with type I loci.
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spelling pubmed-40414162014-06-11 Classification and evolution of type II CRISPR-Cas systems Chylinski, Krzysztof Makarova, Kira S. Charpentier, Emmanuelle Koonin, Eugene V. Nucleic Acids Res Survey and Summary The CRISPR-Cas systems of archaeal and bacterial adaptive immunity are classified into three types that differ by the repertoires of CRISPR-associated (cas) genes, the organization of cas operons and the structure of repeats in the CRISPR arrays. The simplest among the CRISPR-Cas systems is type II in which the endonuclease activities required for the interference with foreign deoxyribonucleic acid (DNA) are concentrated in a single multidomain protein, Cas9, and are guided by a co-processed dual-tracrRNA:crRNA molecule. This compact enzymatic machinery and readily programmable site-specific DNA targeting make type II systems top candidates for a new generation of powerful tools for genomic engineering. Here we report an updated census of CRISPR-Cas systems in bacterial and archaeal genomes. Type II systems are the rarest, missing in archaea, and represented in ∼5% of bacterial genomes, with an over-representation among pathogens and commensals. Phylogenomic analysis suggests that at least three cas genes, cas1, cas2 and cas4, and the CRISPR repeats of the type II-B system were acquired via recombination with a type I CRISPR-Cas locus. Distant homologs of Cas9 were identified among proteins encoded by diverse transposons, suggesting that type II CRISPR-Cas evolved via recombination of mobile nuclease genes with type I loci. Oxford University Press 2014-06-01 2014-04-11 /pmc/articles/PMC4041416/ /pubmed/24728998 http://dx.doi.org/10.1093/nar/gku241 Text en Published by Oxford University Press on behalf of Nucleic Acids Research 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.
spellingShingle Survey and Summary
Chylinski, Krzysztof
Makarova, Kira S.
Charpentier, Emmanuelle
Koonin, Eugene V.
Classification and evolution of type II CRISPR-Cas systems
title Classification and evolution of type II CRISPR-Cas systems
title_full Classification and evolution of type II CRISPR-Cas systems
title_fullStr Classification and evolution of type II CRISPR-Cas systems
title_full_unstemmed Classification and evolution of type II CRISPR-Cas systems
title_short Classification and evolution of type II CRISPR-Cas systems
title_sort classification and evolution of type ii crispr-cas systems
topic Survey and Summary
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4041416/
https://www.ncbi.nlm.nih.gov/pubmed/24728998
http://dx.doi.org/10.1093/nar/gku241
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