Cytochrome P450 27A1 (CYP27A1)

CYP27A1 is a member of the cytochrome P450 superfamily of enzymes. This mitochondrial protein oxidizes cholesterol intermediates as part of the bile synthesis pathway. Since the conversion of cholesterol to bile acids is the major route for removing cholesterol from the body, this protein is important for overall cholesterol homeostasis. Mutations in this gene cause cerebrotendinous xanthomatosis, a rare autosomal recessive lipid storage disease.

CYP27A1 participates in the degradation of cholesterol to bile acids in both the classic and acidic pathways. It is the initiating enzyme in the acidic pathway to bile acids, yielding oxysterols by introducing a hydroxyl group to the carbon at the 27 position in cholesterol.