KEGG   ENZYME: 1.14.99.9Help
Entry
EC 1.14.99.9                Enzyme                                 
Name
steroid 17alpha-monooxygenase;
steroid 17alpha-hydroxylase;
cytochrome P-45017alpha;
cytochrome P-450 (P-45017alpha,lyase);
17alpha-hydroxylase-C17,20 lyase;
CYP17;
CYP17A1 (gene name)
Class
Oxidoreductases;
Acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2;
Miscellaneous
BRITE hierarchy
Sysname
steroid,NADPH---hemoprotein reductase:oxygen oxidoreductase (17alpha-hydroxylating)
Reaction(IUBMB)
a C21-steroid + [reduced NADPH---hemoprotein reductase] + O2 = a 17alpha-hydroxy-C21-steroid + [oxidized NADPH---hemoprotein reductase] + H2O [RN:R02131]
Reaction(KEGG)
Substrate
C21-steroid;
[reduced NADPH---hemoprotein reductase];
O2 [CPD:C00007]
Product
17alpha-hydroxy-C21-steroid;
[oxidized NADPH---hemoprotein reductase];
H2O [CPD:C00001]
Comment
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 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 4.1.2.30, 7alpha-hydroxyprogesterone aldolase). The ratio of the 17alpha-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.
Pathway
Steroid hormone biosynthesis
Metabolic pathways
Orthology
K00512  
cytochrome P450, family 17, subfamily A (steroid 17alpha-monooxygenase)
Genes
HSA: 
1586(CYP17A1)
PTR: 
450141(CYP17A1)
PPS: 
GGO: 
PON: 
MCC: 
678693(CYP17A1)
MMU: 
13074(Cyp17a1)
RNO: 
25146(Cyp17a1)
CFA: 
477807(CYP17A1)
AML: 
FCA: 
493967(CYP17A1)
BTA: 
281739(CYP17A1) 782561(CYP17A1) 784256
SSC: 
403330(CYP17A1)
ECB: 
100034232(CYP17A1)
SHR: 
100915970
OAA: 
100080906
GGA: 
425056(CYP17A1)
MGP: 
100540331
ACS: 
100553634 100553834
XLA: 
100036774(cyp17a1)
XTR: 
100145650(cyp17a1)
DRE: 
399692(cyp17a1)
TRU: 
100125798(cyp17a1)
OLA: 
100125816(cyp17)
BFO: 
BRAFLDRAFT_94132
 » show all
Taxonomy
Reference
1  [PMID:13549484]
  Authors
LYNN WS Jr, BROWN RH.
  Title
The conversion of progesterone to androgens by testes.
  Journal
J. Biol. Chem. 232 (1958) 1015-30.
  Organism
Rattus norvegicus [GN:rno], Cavia porcellus
Reference
2  [PMID:6966286]
  Authors
Yoshida KI, Oshima H, Troen P.
  Title
Studies of the human testis. XIII. Properties of nicotinamide adenine dinucleotide (reduced form)-linked 17 alpha-hydroxylation.
  Journal
J. Clin. Endocrinol. Metab. 50 (1980) 895-9.
  Organism
Homo sapiens [GN:hsa]
Reference
3  [PMID:12693981]
  Authors
Gilep AA, Estabrook RW, Usanov SA
  Title
Molecular cloning and heterologous expression in E. coli of cytochrome P45017alpha. Comparison of structural and functional properties of substrate-specific cytochromes P450 from different species.
  Journal
Biochemistry. (Mosc). 68 (2003) 86-98.
Reference
4  [PMID:17386955]
  Authors
Kolar NW, Swart AC, Mason JI, Swart P
  Title
Functional expression and characterisation of human cytochrome P45017alpha in Pichia pastoris.
  Journal
J. Biotechnol. 129 (2007) 635-44.
Reference
5  [PMID:18707589]
  Authors
Pechurskaya TA, Lukashevich OP, Gilep AA, Usanov SA
  Title
Engineering, expression, and purification of "soluble" human cytochrome P45017alpha and its functional characterization.
  Journal
Biochemistry. (Mosc). 73 (2008) 806-11.
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 
CAS: 
9029-67-8
DBGET integrated database retrieval system