title: At the crossroads of steroid hormone biosynthesis: the role, substrate specificity and evolutionary development of CYP17.
abstract: Cytochrome P450s play critical roles in the metabolism of various bioactive compounds. One of the crucial functions of cytochrome P450s in Chordata is in the biosynthesis of steroid hormones. Steroid 17alpha-hydroxylase/17,20-lyase (CYP17) is localized in endoplasmic reticulum membranes of steroidogenic cells. CYP17 catalyzes the 17alpha-hydroxylation reaction of delta4-C₂₁ steroids (progesterone derivatives) and delta5-C₂₁ steroids (pregnenolone derivatives) as well as the 17,20-lyase reaction producing C₁₉-steroids, a key branch point in steroid hormone biosynthesis. Depending on CYP17 activity, the steroid hormone biosynthesis pathway is directed to either the formation of mineralocorticoids and glucocorticoids or sex hormones. In the present review, the current information on CYP17 is analyzed and discussed.
authors.affiliation: Institute of Bioorganic Chemistry NASB, Kuprevich Str. 5/2, 220141 Minsk, Belarus.
authors.forename: Andrei A
authors.initials: AA
authors.lastname: Gilep
authors.forename: Tatyana A
authors.initials: TA
authors.lastname: Sushko
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Usanov
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019143:Evolution, Molecular; D006728:Hormones / Q000096:biosynthesis*; D006801:Humans; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics / Q000378:metabolism*; D013256:Steroids / Q000096:biosynthesis*; D013379:Substrate Specificity
chemical_list: D006728:Hormones; D013256:Steroids; D013254:Steroid 17-alpha-Hydroxylase