ENZYME entry: EC 1.14.14.19

Accepted Name

steroid 17alpha-monooxygenase

Alternative Name(s)

CYP17

CYP17A1

cytochrome p450 XVIIA1

steroid 17alpha-hydroxylase

steroid 17alpha-hydroxylase/17,20 lyase

Reaction catalysed

a C21-steroid + O2 + reduced [NADPH--hemoprotein reductase] = a 17alpha-hydroxy-C21-steroid + H(+) + H2O + oxidized [NADPH--hemoprotein reductase]

Comment(s)

Requires NADPH and EC 1.6.2.4.
Catalyzes two independent reactions at the same active site - the 17alpha-hydroxylation of pregnenolone and progesterone, which is part of glucocorticoid hormones biosynthesis, and the conversion of the 17alpha-hydroxylated products via a 17,20-lyase reaction to form androstenedione and dehydroepiandrosterone, leading to sex hormone biosynthesis (EC 1.14.14.32).
The ratio of the 17alpha-hydroxylase and 17,20-lyase activities is an important factor in determining the directions of steroid hormone biosynthesis toward biosynthesis of glucocorticoid or sex hormones.
Formerly EC 1.14.1.7, EC 1.14.99.9 and EC 1.99.1.9.

Cross-references

BRENDA

EC2PDB

ExplorEnz

PRIAM enzyme-specific profiles

KEGG Ligand Database for Enzyme Nomenclature

IUBMB Enzyme Nomenclature

IntEnz

MEDLINE

MetaCyc

Rhea expert-curated reactions

UniProtKB/Swiss-Prot

All UniProtKB/Swiss-Prot entries referenced in this entry, with possibility to download in different formats, align etc.

All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 1.14.14.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 1.14.-.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 1.-.-.-