C45 family autoproteolytic acyltransferase/hydolase
Members of this family include hydrolases and N-acyltransferases, and belong to the Ntn (N-terminal nucleophile) hydrolase family. Members have an invariant Cys residue (Cys-103 in XP_002569112.1) required both for autoproteolytic processing into alpha and beta chains and for activity. The family is described by MEROPs as a cysteine protease, family C45, because of its autoproteolytic activity. Characterized members include TAN from Drosophila, which removes beta-alanine from both carcinine and N-beta-alanyl dopamine, and isopenicillin-N N-acyltransferase from various fungi. The latter has been heavily studied because of its role in penicillin biosynthesis.