AcrIIIA1 is a protein-RNA anti-CRISPR complex that targets core Cas and accessory nucleases.

ABSTRACT: Clustered regularly-interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) proteins protect bacteria and archaea from their viruses, and anti-CRISPRs (Acrs) are small virus-encoded proteins that inhibit CRISPR-Cas immunity. Over 80 families of Acrs have been described to date; however, only three of these subvert Type III CRISPR-Cas immunity. Type III systems employ a complex network of Cas and accessory nucleases to degrade viral nucleic acids. Here, we discover and characterize AcrIIIA1, the first Type III-A specific anti-CRISPR protein. We demonstrate that AcrIIIA1 binds to Csm2 within the Cas10-Csm effector complex and attenuates Cas10's DNase activity and second messenger production. Additionally, AcrIIIA1 associates with fragmented t(m)RNAs (acrIIIA1-RNAs), and w

SUBMITTER: Chou-Zheng L 

PROVIDER: S-EPMC11662646 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature