cytochrome P450 family 76 and similar cytochrome P450s
Characterized members of the plant cytochrome P450 family 76 (CYP76 or Cyp76) include: Catharanthus roseus CYP76B6, a multifunctional enzyme catalyzing two sequential oxidation steps leading to the formation of 8-oxogeraniol from geraniol; the Brassicaceae-specific CYP76C subfamily of enzymes that are involved in the metabolism of monoterpenols and phenylurea herbicides; and two P450s from Lamiaceae, CYP76AH and CYP76AK, that are involved in the oxidation of abietane diterpenes. CYP76AH produces ferruginol and 11-hydroxyferruginol, while CYP76AK catalyzes oxidations at the C20 position. Also included in this group is Berberis stolonifera Cyp80, also called berbamunine synthase or (S)-N-methylcoclaurine oxidase [C-O phenol-coupling], that catalyzes the phenol oxidation of N-methylcoclaurine to form the bisbenzylisoquinoline alkaloid berbamunine. The CYP76-like family belongs to the large cytochrome P450 (P450, CYP) superfamily of heme-containing proteins that catalyze a variety of oxidative reactions of a large number of structurally different endogenous and exogenous compounds in organisms from all major domains of life. CYPs bind their diverse ligands in a buried, hydrophobic active site, which is accessed through a substrate access channel formed by two flexible helices and their connecting loop.