| EC |
1.14.14.19 |
| Accepted name: |
steroid 17α-monooxygenase |
| Reaction: |
a C21-steroid + [reduced NADPH—hemoprotein reductase] + O2 = a 17α-hydroxy-C21-steroid + [oxidized NADPH—hemoprotein reductase] + H2O
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| Other name(s): |
steroid 17α-hydroxylase; cytochrome P-450 17α; cytochrome P-450 (P-450 17α,lyase); 17α-hydroxylase-C17,20 lyase; CYP17; CYP17A1 (gene name) |
| Systematic name: |
steroid,NADPH—hemoprotein reductase:oxygen oxidoreductase (17α-hydroxylating) |
| Comments: |
Requires NADPH and EC 1.6.2.4, NADPH—hemoprotein reductase. A microsomal hemeprotein that catalyses two independent reactions at the same active site - the 17α-hydroxylation of pregnenolone and progesterone, which is part of glucocorticoid hormones biosynthesis, and the conversion of the 17α-hydroxylated products via a 17,20-lyase reaction to form androstenedione and dehydroepiandrosterone, leading to sex hormone biosynthesis (EC 1.14.14.32, 17α-hydroxyprogesterone deacetylase). The ratio of the 17α-hydroxylase and 17,20-lyase activities is an important factor in determining the directions of steroid hormone biosynthesis towards biosynthesis of glucocorticoid or sex hormones. |
| Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9029-67-8 |
| References: |
| 1. |
Lynn, W.S. and Brown, R.H. The conversion of progesterone to androgens by testes. J. Biol. Chem. 232 (1958) 1015–1030. [PMID: 13549484] |
| 2. |
Yoshida, K.-I., Oshima, H. and Troen, P. Studies of the human testis. XIII. Properties of nicotinamide adenine dinucleotide (reduced form)-linked 17α-hydroxylation. J. Clin. Endocrinol. Metab. 50 (1980) 895–899. [DOI] [PMID: 6966286] |
| 3. |
Gilep, A.A., Estabrook, R.W. and Usanov, S.A. Molecular cloning and heterologous expression in E. coli of cytochrome P45017α. Comparison of structural and functional properties of substrate-specific cytochromes P450 from different species. Biochemistry (Mosc.) 68 (2003) 86–98. [PMID: 12693981] |
| 4. |
Kolar, N.W., Swart, A.C., Mason, J.I. and Swart, P. Functional expression and characterisation of human cytochrome P45017α in Pichia pastoris. J. Biotechnol. 129 (2007) 635–644. [DOI] [PMID: 17386955] |
| 5. |
Pechurskaya, T.A., Lukashevich, O.P., Gilep, A.A. and Usanov, S.A. Engineering, expression, and purification of "soluble" human cytochrome P45017α and its functional characterization. Biochemistry (Mosc.) 73 (2008) 806–811. [PMID: 18707589] |
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| [EC 1.14.14.19 created 1961 as EC 1.99.1.9, transferred 1965 to EC 1.14.1.7, transferred 1972 to EC 1.14.99.9, modified 2013, transferred 2015 to EC 1.14.14.19] |
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