CRISPR system ring nuclease SSO1393

UniProtKB accession:  Q97YD2

Grouped By:  Matching UniProtKB accession

UniProtKB description:  CRISPR (clustered regularly interspaced short palindromic repeat) is an adaptive immune system that provides protection against mobile genetic elements (viruses, transposable elements and conjugative plasmids). CRISPR clusters contain spacers, sequences complementary to antecedent mobile elements, and target invading nucleic acids. CRISPR clusters are transcribed and processed into CRISPR RNA (crRNA) (Probable). A nuclease that degrades cyclic oligoadenylates (cOA), second messengers that induce an antiviral state important for defense against invading nucleic acids. Destruction of cOA deactivates the Csx1 ribonuclease, preventing uncontrolled degradation of cellular RNA. Slowly degrades cA4 (a tetraadenylate ring) into first a linear tetraadenylate product and secondly into a linear diadenylate product with 5'-OH and 2',3'-cyclic phosphate termini. Is 10-fold less active than SSO2081, suggesting it plays a minor role in cA4 degradation. There may be 2 active sites per homodimer (PubMed:30232454).