Function
Cytochrome P450 monooxygenase; part of the gene cluster that mediates the biosynthesis of ochratoxin A (OTA), a mycotoxin demonstrated to have nephrotoxic, immunotoxic, genotoxic, neurotoxic, and teratogenic properties (PubMed:22341916, PubMed:27667988, PubMed:27959549). OTA is composed of a chlorinated type I polyketide dihydroisocoumarin moiety linked to L-phenyl-alanine (PubMed:27959549). The highly reducing polyketide synthase ota1 catalyzes the formation of the isocoumarin group during the initial stages of biosynthesis, starting from acetate and malonate, to originate the characteristic pentaketide skeleton 7-methylmellein (7-MM) of the OTA molecule (PubMed:27959549). 7-MM is then oxidized into 7-carboxymellein (also called ochratoxin beta) (By similarity). The NRPS ota2 is involved in the linking of phenylalanine to dihydroisocoumarin ring (By similarity). The reaction catalyzed by ota2 results in the production of ochratoxin B (OTB), which is the non-chlorinated analog of OTA and which subsequently serves as the substrate of the halogenase ota5 for chlorination activity to form the final molecular structure of OTA, containing a chlorine atom in the C-5 position of the molecule (By similarity). The role of the cytochrome P450 monoogygenae ota3 within the ochratoxin synthesis cluster has not been identified yet.
Sequence
MSIDTLLYTSLAVGAVYLASVALYELYWSPLAHIPGPKLAACTRLYEFFYDVVCGGQYTFKIADLHKQYGPIIRISPREIHIHDPNYYETLYATNSPRNKDPWFTAHFGVDESAFSTLDYRLHRSRRAMIAPFFAKARMDGAQPLIKANLAKLIRHLDAHASSQSVLKVEVAYNSFTGDVITGYTSYRSFEYLETTDMVPIWSETVRNLVESGMLSRHLPGFFPLLAWAGSRCIAAVYPKLLPVIAFRMKCAQEVNFMWTNSEEGKKEAIQSGCSEPALFPELVSRASSAPDITEERLLHEFITIVAAGTETTAHTMTVCTFHIAHNQSILDKLREELDNRFHSNADMDLQTLEQLPYLTGIIYEGLRLSYGLSHRLQRISPIDPLKYKDIAIPPNTPVGMSSALMHHDESIFPQSHEFIPERWTDPNDRRRLNKYMVSFSKGSRQCIGMNLAFAELYLGIATLFRRYDMKLHDTTLDDVQLHGDKMLPRAKNGSKGVRVTLRRAQSVG