C-terminal cytochrome P450 domain of linoleate diol synthase and similar cytochrome P450s
This family contains Gaeumannomyces graminis linoleate diol synthase (LDS) and similar proteins including Ssp1 from the phytopathogenic basidiomycete Ustilago maydis. LDS, also called linoleate (8R)-dioxygenase, catalyzes the dioxygenation of linoleic acid to (8R)-hydroperoxylinoleate and the isomerization of the resulting hydroperoxide to (7S,8S)-dihydroxylinoleate. Ssp1 is expressed in mature teliospores, which are produced by U. maydis only after infection of its host plant, maize. Ssp1 is localized on lipid bodies in germinating teliospores, suggesting a role in the mobilization of storage lipids. LDS and Ssp1 contain an N-terminal dioxygenase domain related to animal heme peroxidases, and a C-terminal cytochrome P450 domain. The LDS-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.