CRISPR system subtype II-B RNA-guided endonuclease Cas9/Csx12
Members of this family of CRISPR-associated (cas) protein are found, so far, in CRISPR/cas loci in Wolinella succinogenes DSM 1740, Legionella pneumophila str. Paris, and Francisella tularensis, where the last probably is an example of a degenerate CRISPR locus, having neither repeats nor a functional Cas1. The characteristic repeat length is 37 base pairs and period is about 72. One region of this large protein shows sequence similarity to pfam01844, HNH endonuclease.
Jiyao W et al.(2023). "The conserved domain database in 2023.",