A Conserved Structural Chassis for Mounting Versatile CRISPR RNA-Guided Immune Responses.

ABSTRACT: Bacteria and archaea rely on CRISPR (clustered regularly interspaced short palindromic repeats) RNA-guided adaptive immune systems for targeted elimination of foreign nucleic acids. These immune systems have been divided into three main types, and the first atomic-resolution structure of a type III RNA-guided immune complex provides new insights into the mechanisms of nucleic acid degradation. Here we compare the crystal structure of a type III complex to recently determined structures of DNA-targeting type I CRISPR complexes. Structural comparisons support previous assertions that type I and type III systems share a common ancestor and reveal how a conserved structural chassis is used to support RNA-, DNA-, or both RNA- and DNA-targeting mechanisms.

SUBMITTER: Jackson RN 

PROVIDER: S-EPMC4465340 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature