Protein: Cholesterol side-chain cleavage enzyme, mitochondrial (EC 1.14.15.6) (CYPXIA1) (Cholesterol desmolase) (Cytochrome P450 11A1) (Cytochrome P450(scc)) (Q9QZ82)
Organism: Mus musculus (Mouse)
Function: A cytochrome P450 monooxygenase that catalyzes the side-chain hydroxylation and cleavage of cholesterol to pregnenolone, the precursor of most steroid hormones. 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. 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).
Subcellular location: Mitochondrion inner membrane {ECO:0000250|UniProtKB:P14137}; Peripheral membrane protein {ECO:0000305}. Note=Localizes to the matrix side of the mitochondrion inner membrane. {ECO:0000250|UniProtKB:P14137}.
Sequence: MLAKGLSLRSVLVKGCQPFLSPTWQGPVLSTGKGAGTSTSSPRSFNEIPSPGDNGWLNLYHFWRESGTQKIHYHQMQSFQKYGPIYREKLGTLESVYIVDPKDASILFSCEGPNPERFLVPPWVAYHQYYQRPIGVLFKSSDAWKKDRIVLNQEVMAPGAIKNFVPLLEGVAQDFIKVLHRRIKQQNSGNFSGVISDDLFRFSFESISSVIFGERMGMLEEIVDPEAQRFINAVYQMFHTSVPMLNLPPDFFRLLRTKTWKDHAAAWDVIFNKADEYTQNFYWDLRQKRDFSQYPGVLYSLLGGNKLPFKNIQANITEMLAGGVDTTSMTLQWNLYEMAHNLKVQEMLRAEVLAARRQAQGDMAKMVQLVPLLKASIKETLRLHPISVTLQRYTVNDLVLRNYKIPAKTLVQVASFAMGRDPGFFPNPNKFDPTRWLEKSQNTTHFRYLGFGWGVRQCLGRRIAELEMTILLINLLENFRIEVQNLRDVGTKFSLILMPENPILFNFQPLKQDLGPAVTRKDNTVN
InterPro domains: - IPR036396: Cytochrome P450 superfamily (homologous_superfamily) [39-521]
- IPR017972: Cytochrome P450, conserved site (conserved_site) [451-460]
- IPR001128: Cytochrome P450 (family) [49-506]
- IPR002401: Cytochrome P450, E-class, group I (family) [79-481]
- IPR050479: Cytochrome P450, families 11 and 27 (family) [34-510]
Interaction partners: - 3 beta-hydroxysteroid dehydrogenase/Delta 5-->4-isomerase type 1
- Adrenodoxin, mitochondrial
- 3 beta-hydroxysteroid dehydrogenase/Delta 5-->4-isomerase type 2
- 3 beta-hydroxysteroid dehydrogenase/Delta 5-->4-isomerase type 6
- Steroidogenic acute regulatory protein, mitochondrial
- NADPH:adrenodoxin oxidoreductase, mitochondrial
- Steroid 21-hydroxylase
- Steroid 17-alpha-hydroxylase/17,20 lyase
- Cytochrome P450 7B1
- 3 beta-hydroxysteroid dehydrogenase/Delta 5-->4-isomerase type 3
Gene Ontology annotations:
Molecular Function (MF): GO:0003674 (molecular function), GO:0003824 (catalytic activity), GO:0016491 (oxidoreductase activity), GO:0016705 (oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen), GO:0004497 (monooxygenase activity), GO:0016713 (oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced iron-sulfur protein as one donor, and incorporation of one atom of oxygen)
Biological Process (BP): GO:0008150 (biological process), GO:0008152 (metabolic process), GO:0065007 (biological regulation), GO:0009987 (cellular process), GO:0065008 (regulation of biological quality), GO:0009058 (biosynthetic process), GO:0044237 (cellular metabolic process), GO:0008207 (C21-steroid hormone metabolic process), GO:0044281 (small molecule metabolic process), GO:0042445 (hormone metabolic process), GO:0071704 (organic substance metabolic process), GO:0044238 (primary metabolic process), GO:1901615 (organic hydroxy compound metabolic process), GO:1901360 (organic cyclic compound metabolic process), GO:1901576 (organic substance biosynthetic process), GO:0006629 (lipid metabolic process), GO:0044249 (cellular biosynthetic process), GO:0006700 (C21-steroid hormone biosynthetic process), GO:0006066 (alcohol metabolic process), GO:0010817 (regulation of hormone levels), GO:0042446 (hormone biosynthetic process), GO:0016125 (sterol metabolic process), GO:1902652 (secondary alcohol metabolic process), GO:1901362 (organic cyclic compound biosynthetic process), GO:0008202 (steroid metabolic process), GO:0008610 (lipid biosynthetic process), GO:0006694 (steroid biosynthetic process), GO:0008203 (cholesterol metabolic process), GO:0120178 (steroid hormone biosynthetic process)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0005622 (intracellular anatomical structure), GO:0043226 (organelle), GO:0005737 (cytoplasm), GO:0043229 (intracellular organelle), GO:0005739 (mitochondrion), GO:0043227 (membrane-bounded organelle), GO:0043231 (intracellular membrane-bounded organelle)