Name	CYP11A1 View Modifications
Full Name	Cholesterol side-chain cleavage enzyme, mitochondrial
Synonyms	CYPXIA1, Cholesterol desmolase, Cytochrome P450 11A1, Cytochrome P450(scc) \| CYP11A
Primary ID	P05108
Links	- -
Type	protein
Relations	7
Pathways	Sex Hormone Biosynthesis
Function	A cytochrome P450 monooxygenase that catalyzes the side-chain hydroxylation and cleavage of cholesterol to pregnenolone, the precursor of most steroid hormones (PubMed:21636783). Catalyzes three sequential oxidation reactions of cholesterol, namely the hydroxylation at C22 followed with the hydroxylation at C20 to yield 20R,22R-hydroxycholesterol that is further cleaved between C20 and C22 to yield the C21-steroid pregnenolone and 4-methylpentanal (PubMed:21636783). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate and reducing the second into a water molecule. Two electrons are provided by NADPH via a two-protein mitochondrial transfer system comprising flavoprotein FDXR (adrenodoxin/ferredoxin reductase) and nonheme iron-sulfur protein FDX1 or FDX2 (adrenodoxin/ferredoxin) (PubMed:21636783).