TitleRNA-guided RNA cleavage by a CRISPR RNA-Cas protein complex.
Publication TypeJournal Article
Year of Publication2009
AuthorsHale CR, Zhao P, Olson S, Duff MO, Graveley BR, Wells L, Terns RM, Terns MP
Date Published2009 Nov 25
KeywordsArchaeal Proteins, Base Sequence, Pyrococcus furiosus, RNA Interference, RNA, Archaeal, RNA, Guide, RNA, Viral
AbstractCompelling evidence indicates that the CRISPR-Cas system protects prokaryotes from viruses and other potential genome invaders. This adaptive prokaryotic immune system arises from the clustered regularly interspaced short palindromic repeats (CRISPRs) found in prokaryotic genomes, which harbor short invader-derived sequences, and the CRISPR-associated (Cas) protein-coding genes. Here, we have identified a CRISPR-Cas effector complex that is comprised of small invader-targeting RNAs from the CRISPR loci (termed prokaryotic silencing (psi)RNAs) and the RAMP module (or Cmr) Cas proteins. The psiRNA-Cmr protein complexes cleave complementary target RNAs at a fixed distance from the 3' end of the integral psiRNAs. In Pyrococcus furiosus, psiRNAs occur in two size forms that share a common 5' sequence tag but have distinct 3' ends that direct cleavage of a given target RNA at two distinct sites. Our results indicate that prokaryotes possess a unique RNA silencing system that functions by homology-dependent cleavage of invader RNAs.
Alternate JournalCell
PubMed ID19945378