Csx3 is a cyclic oligonucleotide phosphodiesterase associated with type III CRISPR-Cas that degrades the second messenger cA₄.

ABSTRACT: Cas10 is the signature gene for type III CRISPR-Cas surveillance complexes. Unlike type I and type II systems, type III systems do not require a protospacer adjacent motif and target nascent RNA associated with transcriptionally active DNA. Further, target RNA recognition activates the cyclase domain of Cas10, resulting in the synthesis of cyclic oligoadenylate second messengers. These second messengers are recognized by ancillary Cas proteins harboring CRISPR-associated Rossmann fold (CARF) domains and regulate the activities of these proteins in response to invading nucleic acid. Csx3 is a distant member of the CARF domain superfamily previously characterized as a Mn²⁺-dependent deadenylation exoribonuclease. However, its specific role in CRISPR-Cas defense remains to be deter

SUBMITTER: Brown S 

PROVIDER: S-EPMC7606696 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature