C2c2 Is a Single-Component Programmable RNA-guided RNA-targeting CRISPR Effector

Science. 2016 Aug 5;353(6299):aaf5573. doi: 10.1126/science.aaf5573. Epub 2016 Jun 2.

Abstract

The clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated genes (Cas) adaptive immune system defends microbes against foreign genetic elements via DNA or RNA-DNA interference. We characterize the class 2 type VI CRISPR-Cas effector C2c2 and demonstrate its RNA-guided ribonuclease function. C2c2 from the bacterium Leptotrichia shahii provides interference against RNA phage. In vitro biochemical analysis shows that C2c2 is guided by a single CRISPR RNA and can be programmed to cleave single-stranded RNA targets carrying complementary protospacers. In bacteria, C2c2 can be programmed to knock down specific mRNAs. Cleavage is mediated by catalytic residues in the two conserved Higher Eukaryotes and Prokaryotes Nucleotide-binding (HEPN) domains, mutations of which generate catalytically inactive RNA-binding proteins. These results broaden our understanding of CRISPR-Cas systems and suggest that C2c2 can be used to develop new RNA-targeting tools.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adaptive Immunity / genetics*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Base Sequence
  • CRISPR-Cas Systems*
  • Clustered Regularly Interspaced Short Palindromic Repeats
  • Endoribonucleases / chemistry
  • Endoribonucleases / genetics
  • Endoribonucleases / metabolism*
  • Escherichia coli / genetics
  • Escherichia coli / immunology
  • Escherichia coli / virology
  • Gene Knockdown Techniques
  • Genetic Loci
  • Leptotrichia / enzymology*
  • Leptotrichia / genetics
  • Leptotrichia / immunology
  • Levivirus / immunology
  • Molecular Sequence Data
  • Protein Structure, Tertiary
  • RNA Cleavage
  • RNA, Guide / metabolism*

Substances

  • Bacterial Proteins
  • RNA, Guide
  • Endoribonucleases