CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) and associated Cas proteins comprise a system for heritable host defense by prokaryotic cells against phage and other foreign DNA; Small protein often seen in proximity to Csx1 (COG1517) family; also known as VVA1548 family
Jiyao W et al.(2023). "The conserved domain database in 2023.",