Format

Send to

Choose Destination
Mol Cell. 2015 Nov 5;60(3):385-97. doi: 10.1016/j.molcel.2015.10.008. Epub 2015 Oct 22.

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

Author information

1
Skolkovo Institute of Science and Technology, Skolkovo, 143025, Russia; NCBI, NLM, NIH, Bethesda, MD 20894, USA.
2
Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
3
NCBI, NLM, NIH, Bethesda, MD 20894, USA.
4
Waksman Institute for Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
5
Skolkovo Institute of Science and Technology, Skolkovo, 143025, Russia; Waksman Institute for Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, 123182, Russia.
6
Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Electronic address: zhang@broadinstitute.org.
7
NCBI, NLM, NIH, Bethesda, MD 20894, USA. Electronic address: koonin@ncbi.nlm.nih.gov.

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.

KEYWORDS:

CRISPR-Cas adaptive immunity; Cas9; Cpf1; HEPN domain; PAM; RNA-seq; RuvC-like endonuclease; computational discovery pipeline; crRNA; tracrRNA

PMID:
26593719
PMCID:
PMC4660269
DOI:
10.1016/j.molcel.2015.10.008
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center