A0A0S2Z3R3 · A0A0S2Z3R3_HUMAN
- ProteinCholesterol side-chain cleavage enzyme, mitochondrial
- GeneCYP11A1
- StatusUniProtKB unreviewed (TrEMBL)
- Organism
- Amino acids521 (go to sequence)
- Protein existenceEvidence at transcript level
- Annotation score4/5
Function
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).
Catalytic activity
- (20R,22R)-20,22-dihydroxycholesterol + 2 H+ + O2 + 2 reduced [adrenodoxin] = 4-methylpentanal + 2 H2O + 2 oxidized [adrenodoxin] + pregnenoloneThis reaction proceeds in the forward direction.
- (22R)-hydroxycholesterol + 2 H+ + O2 + 2 reduced [adrenodoxin] = (20R,22R)-20,22-dihydroxycholesterol + H2O + 2 oxidized [adrenodoxin]This reaction proceeds in the forward direction.
- cholesterol + 2 H+ + O2 + 2 reduced [adrenodoxin] = (22R)-hydroxycholesterol + H2O + 2 oxidized [adrenodoxin]This reaction proceeds in the forward direction.
Cofactor
Pathway
Lipid metabolism; C21-steroid hormone metabolism.
Steroid metabolism; cholesterol metabolism.
Features
Showing features for binding site.
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | mitochondrial inner membrane | |
Molecular Function | cholesterol monooxygenase (side-chain-cleaving) activity | |
Molecular Function | heme binding | |
Molecular Function | iron ion binding | |
Biological Process | C21-steroid hormone biosynthetic process | |
Biological Process | cellular response to peptide hormone stimulus | |
Biological Process | cholesterol metabolic process | |
Biological Process | cortisol metabolic process | |
Biological Process | glucocorticoid biosynthetic process |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameCholesterol side-chain cleavage enzyme, mitochondrial
- EC number
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Homo
Accessions
- Primary accessionA0A0S2Z3R3
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Mitochondrion inner membrane ; Peripheral membrane protein
Note: Localizes to the matrix side of the mitochondrion inner membrane.
Keywords
- Cellular component
Disease & Variants
Organism-specific databases
Expression
Gene expression databases
Interaction
Subunit
Interacts with FDX1/adrenodoxin.
Structure
Sequence
- Sequence statusFragment
- Length521
- Mass (Da)60,102
- Last updated2016-02-17 v1
- ChecksumAB0501E7A5665D8B
Features
Showing features for non-terminal residue.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Non-terminal residue | 521 | |||||
Sequence: Q |
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
KU178011 EMBL· GenBank· DDBJ | ALQ33469.1 EMBL· GenBank· DDBJ | mRNA |