Discovery and Functional Characterization of Diverse Class 2 CRISPR-Cas Systems.

Mol Cell
Authors
Keywords
Abstract

Microbial CRISPR-Cas systems are divided into Class 1, with multisubunit effector complexes, and Class 2, with single protein effectors. Currently, only two Class 2 effectors, Cas9 and Cpf1, are known. We describe here three distinct Class 2 CRISPR-Cas systems. The effectors of two of the identified systems, C2c1 and C2c3, contain RuvC-like endonuclease domains distantly related to Cpf1. The third system, C2c2, contains an effector with two predicted HEPN RNase domains. Whereas production of mature CRISPR RNA (crRNA) by C2c1 depends on tracrRNA, C2c2 crRNA maturation is tracrRNA independent. We found that C2c1 systems can mediate DNA interference in a 5'-PAM-dependent fashion analogous to Cpf1. However, unlike Cpf1, which is a single-RNA-guided nuclease, C2c1 depends on both crRNA and tracrRNA for DNA cleavage. Finally, comparative analysis indicates that Class 2 CRISPR-Cas systems evolved on multiple occasions through recombination of Class 1 adaptation modules with effector proteins acquired from distinct mobile elements.

Year of Publication
2015
Journal
Mol Cell
Volume
60
Issue
3
Pages
385-97
Date Published
2015 Nov 05
ISSN
1097-4164
URL
DOI
10.1016/j.molcel.2015.10.008
PubMed ID
26593719
PubMed Central ID
PMC4660269
Links
Grant list
R01 MH110049 / MH / NIMH NIH HHS / United States
5DP1-MH100706 / DP / NCCDPHP CDC HHS / United States
R01 GM104071 / GM / NIGMS NIH HHS / United States
DP1 MH100706 / MH / NIMH NIH HHS / United States
R01 DK097768 / DK / NIDDK NIH HHS / United States
5R01DK097768-03 / DK / NIDDK NIH HHS / United States
GM10407 / GM / NIGMS NIH HHS / United States