cas9

Has a bilobed architecture with a recognition lobe (REC, residues 41-425) and a discontinuous nuclease lobe (NUC, residues 1-40 and 453-1053); the crRNA-target DNA lies in a channel between the 2 lobes (PubMed:26317473). The NUC lobe has 2 endonuclease domains. The discontinuous RuvC-like domain in NUC cleaves the target DNA noncomplementary to crRNA while the HNH nuclease domain cleaves the target DNA complementary to crRNA (PubMed:26317473).

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). In type II CRISPR systems correct processing of pre-crRNA requires a trans-encoded small RNA (tracrRNA), endogenous ribonuclease 3 (rnc) and this protein. The tracrRNA serves as a guide for ribonuclease 3-aided processing of pre-crRNA. Subsequently Cas9/crRNA/tracrRNA endonucleolytically cleaves linear or circular dsDNA target complementary to the spacer; Cas9 is inactive in the absence of the 2 guide RNAs (gRNA). Cas9 recognizes the protospacer adjacent motif (PAM) in the CRISPR repeat sequences to help distinguish self versus nonself, as targets within the bacterial CRISPR locus do not have PAMs. PAM recognition is also required for catalytic activity.

Belongs to the CRISPR-associated Cas9 family. Subtype II-A subfamily.

CRISPR-associated endonuclease Cas9, SaCas9, cas9

• swissprot:J7RUA5

Proteins

Immuno-oncology

123949Da