cytochrome P450 family 170, subfamily A, polypeptide 1-like actinobacterial cytochrome P450s
This subfamily is composed of Streptomyces coelicolor cytochrome P450 170A1 (CYP170A1), Streptomyces avermitilis pentalenene oxygenase, and similar actinobacterial cytochrome P450s. CYP170A1, also called epi-isozizaene 5-monooxygenase (EC 18.104.22.168)/(E)-beta-farnesene synthase (EC 22.214.171.124), catalyzes the two-step allylic oxidation of epi-isozizaene to albaflavenone, which is a sesquiterpenoid antibiotic. Pentalenene oxygenase (EC 126.96.36.199) catalyzes the conversion of pentalenene to pentalen-13-al by stepwise oxidation via pentalen-13-ol, a precursor of the neopentalenolactone antibiotic. The CYP170A1-like subfamily 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.