7-alpha-hydroxycholest-4-en-3-one 12-alpha-hydroxylase (CYP8B1)

Involved in bile acid synthesis and is responsible for the conversion of 7 alpha-hydroxy-4-cholesten-3-one into 7 alpha, 12 alpha-dihydroxy-4-cholesten-3-one. Responsible for the balance between formation of cholic acid and chenodeoxycholic acid.

Has a rather broad substrate specificity including a number of 7-alpha- hydroxylated C27 steroids. .