| Literature DB >> 26411297 |
Kira S Makarova1, Yuri I Wolf1, Omer S Alkhnbashi2, Fabrizio Costa2, Shiraz A Shah3, Sita J Saunders2, Rodolphe Barrangou4, Stan J J Brouns5, Emmanuelle Charpentier6, Daniel H Haft1, Philippe Horvath7, Sylvain Moineau8, Francisco J M Mojica9, Rebecca M Terns10, Michael P Terns10, Malcolm F White11, Alexander F Yakunin12, Roger A Garrett3, John van der Oost5, Rolf Backofen2,13, Eugene V Koonin1.
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.Entities:
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Year: 2015 PMID： 26411297 PMCID： PMC5426118 DOI： 10.1038/nrmicro3569
Source DB: PubMed Journal: Nat Rev Microbiol ISSN： 1740-1526 Impact factor: 60.633