Cryo-EM Structures Reveal Mechanism and Inhibition of DNA Targeting by a CRISPR-Cas Surveillance Complex.

ABSTRACT: Prokaryotic cells possess CRISPR-mediated adaptive immune systems that protect them from foreign genetic elements, such as invading viruses. A central element of this immune system is an RNA-guided surveillance complex capable of targeting non-self DNA or RNA for degradation in a sequence- and site-specific manner analogous to RNA interference. Although the complexes display considerable diversity in their composition and architecture, many basic mechanisms underlying target recognition and cleavage are highly conserved. Using cryoelectron microscopy (cryo-EM), we show that the binding of target double-stranded DNA (dsDNA) to a type I-F CRISPR system yersinia (Csy) surveillance complex leads to large quaternary and tertiary structural changes in the complex that are likely necessary in the

SUBMITTER: Guo TW 

PROVIDER: S-EPMC5683424 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature