Diversity and Evolution of Class 2 CRISPR-Cas Systems

Nat Rev Microbiol. 2017 Mar;15(3):169-182. doi: 10.1038/nrmicro.2016.184. Epub 2017 Jan 23.

Abstract

Class 2 CRISPR-Cas systems are characterized by effector modules that consist of a single multidomain protein, such as Cas9 or Cpf1. We designed a computational pipeline for the discovery of novel class 2 variants and used it to identify six new CRISPR-Cas subtypes. The diverse properties of these new systems provide potential for the development of versatile tools for genome editing and regulation. In this Analysis article, we present a comprehensive census of class 2 types and class 2 subtypes in complete and draft bacterial and archaeal genomes, outline evolutionary scenarios for the independent origin of different class 2 CRISPR-Cas systems from mobile genetic elements, and propose an amended classification and nomenclature of CRISPR-Cas.

MeSH terms

  • Archaea / genetics
  • Bacteria / genetics
  • CRISPR-Associated Proteins / genetics*
  • CRISPR-Cas Systems / genetics*
  • Gene Editing / methods*
  • Genome, Archaeal / genetics*
  • Genome, Bacterial / genetics*
  • Protein Domains / genetics*

Substances

  • CRISPR-Associated Proteins