CP11A_HORSE
ID CP11A_HORSE Reviewed; 520 AA.
AC O46515;
DT 01-DEC-2000, integrated into UniProtKB/Swiss-Prot.
DT 01-JUN-1998, sequence version 1.
DT 03-AUG-2022, entry version 120.
DE RecName: Full=Cholesterol side-chain cleavage enzyme, mitochondrial {ECO:0000250|UniProtKB:P05108};
DE EC=1.14.15.6 {ECO:0000250|UniProtKB:P05108};
DE AltName: Full=CYPXIA1;
DE AltName: Full=Cholesterol desmolase;
DE AltName: Full=Cytochrome P450 11A1;
DE AltName: Full=Cytochrome P450(scc);
DE Flags: Precursor;
GN Name=CYP11A1;
OS Equus caballus (Horse).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Laurasiatheria; Perissodactyla; Equidae; Equus.
OX NCBI_TaxID=9796;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC TISSUE=Ovarian follicle membrane;
RX PubMed=11133676; DOI=10.1095/biolreprod64.1.206;
RA Boerboom D., Sirois J.;
RT "Equine P450 cholesterol side-chain cleavage and 3 beta-hydroxysteroid
RT dehydrogenase/delta(5)-delta(4) isomerase: molecular cloning and regulation
RT of their messenger ribonucleic acids in equine follicles during the
RT ovulatory process.";
RL Biol. Reprod. 64:206-215(2001).
CC -!- FUNCTION: A cytochrome P450 monooxygenase that catalyzes the side-chain
CC hydroxylation and cleavage of cholesterol to pregnenolone, the
CC precursor of most steroid hormones. Catalyzes three sequential
CC oxidation reactions of cholesterol, namely the hydroxylation at C22
CC followed with the hydroxylation at C20 to yield 20R,22R-
CC hydroxycholesterol that is further cleaved between C20 and C22 to yield
CC the C21-steroid pregnenolone and 4-methylpentanal. Mechanistically,
CC uses molecular oxygen inserting one oxygen atom into a substrate and
CC reducing the second into a water molecule. Two electrons are provided
CC by NADPH via a two-protein mitochondrial transfer system comprising
CC flavoprotein FDXR (adrenodoxin/ferredoxin reductase) and nonheme iron-
CC sulfur protein FDX1 or FDX2 (adrenodoxin/ferredoxin).
CC {ECO:0000250|UniProtKB:P05108}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=cholesterol + 6 H(+) + 3 O2 + 6 reduced [adrenodoxin] = 4-
CC methylpentanal + 4 H2O + 6 oxidized [adrenodoxin] + pregnenolone;
CC Xref=Rhea:RHEA:35739, Rhea:RHEA-COMP:9998, Rhea:RHEA-COMP:9999,
CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:15379,
CC ChEBI:CHEBI:16113, ChEBI:CHEBI:16581, ChEBI:CHEBI:17998,
CC ChEBI:CHEBI:33737, ChEBI:CHEBI:33738; EC=1.14.15.6;
CC Evidence={ECO:0000250|UniProtKB:P05108};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:35740;
CC Evidence={ECO:0000250|UniProtKB:P05108};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=cholesterol + 2 H(+) + O2 + 2 reduced [adrenodoxin] = (22R)-
CC hydroxycholesterol + H2O + 2 oxidized [adrenodoxin];
CC Xref=Rhea:RHEA:34335, Rhea:RHEA-COMP:9998, Rhea:RHEA-COMP:9999,
CC ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:15379,
CC ChEBI:CHEBI:16113, ChEBI:CHEBI:33737, ChEBI:CHEBI:33738,
CC ChEBI:CHEBI:67237; Evidence={ECO:0000250|UniProtKB:P05108};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:34336;
CC Evidence={ECO:0000250|UniProtKB:P05108};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=(22R)-hydroxycholesterol + 2 H(+) + O2 + 2 reduced
CC [adrenodoxin] = (20R,22R)-20,22-dihydroxycholesterol + H2O + 2
CC oxidized [adrenodoxin]; Xref=Rhea:RHEA:34339, Rhea:RHEA-COMP:9998,
CC Rhea:RHEA-COMP:9999, ChEBI:CHEBI:1294, ChEBI:CHEBI:15377,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:15379, ChEBI:CHEBI:33737,
CC ChEBI:CHEBI:33738, ChEBI:CHEBI:67237;
CC Evidence={ECO:0000250|UniProtKB:P05108};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:34340;
CC Evidence={ECO:0000250|UniProtKB:P05108};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=(20R,22R)-20,22-dihydroxycholesterol + 2 H(+) + O2 + 2 reduced
CC [adrenodoxin] = 4-methylpentanal + 2 H2O + 2 oxidized [adrenodoxin] +
CC pregnenolone; Xref=Rhea:RHEA:34343, Rhea:RHEA-COMP:9998, Rhea:RHEA-
CC COMP:9999, ChEBI:CHEBI:1294, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378,
CC ChEBI:CHEBI:15379, ChEBI:CHEBI:16581, ChEBI:CHEBI:17998,
CC ChEBI:CHEBI:33737, ChEBI:CHEBI:33738;
CC Evidence={ECO:0000250|UniProtKB:P05108};
CC PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:34344;
CC Evidence={ECO:0000250|UniProtKB:P05108};
CC -!- COFACTOR:
CC Name=heme; Xref=ChEBI:CHEBI:30413;
CC Evidence={ECO:0000250|UniProtKB:P05108};
CC -!- PATHWAY: Lipid metabolism; C21-steroid hormone metabolism.
CC {ECO:0000250|UniProtKB:P05108}.
CC -!- PATHWAY: Steroid metabolism; cholesterol metabolism.
CC {ECO:0000250|UniProtKB:P05108}.
CC -!- SUBUNIT: Interacts with FDX1/adrenodoxin.
CC {ECO:0000250|UniProtKB:P05108}.
CC -!- SUBCELLULAR LOCATION: Mitochondrion inner membrane
CC {ECO:0000250|UniProtKB:P14137}; Peripheral membrane protein
CC {ECO:0000305}. Note=Localizes to the matrix side of the mitochondrion
CC inner membrane. {ECO:0000250|UniProtKB:P14137}.
CC -!- SIMILARITY: Belongs to the cytochrome P450 family. {ECO:0000305}.
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DR EMBL; AF031664; AAC04700.1; -; Genomic_DNA.
DR RefSeq; NP_001075990.1; NM_001082521.1.
DR AlphaFoldDB; O46515; -.
DR SMR; O46515; -.
DR STRING; 9796.ENSECAP00000015487; -.
DR PaxDb; O46515; -.
DR PRIDE; O46515; -.
DR GeneID; 100034229; -.
DR KEGG; ecb:100034229; -.
DR CTD; 1583; -.
DR InParanoid; O46515; -.
DR OrthoDB; 561463at2759; -.
DR UniPathway; UPA00229; -.
DR UniPathway; UPA00296; -.
DR Proteomes; UP000002281; Unplaced.
DR GO; GO:0005743; C:mitochondrial inner membrane; ISS:UniProtKB.
DR GO; GO:0008386; F:cholesterol monooxygenase (side-chain-cleaving) activity; ISS:UniProtKB.
DR GO; GO:0020037; F:heme binding; ISS:UniProtKB.
DR GO; GO:0005506; F:iron ion binding; IEA:InterPro.
DR GO; GO:0006700; P:C21-steroid hormone biosynthetic process; ISS:UniProtKB.
DR GO; GO:0071375; P:cellular response to peptide hormone stimulus; IBA:GO_Central.
DR GO; GO:0008203; P:cholesterol metabolic process; ISS:UniProtKB.
DR GO; GO:0034650; P:cortisol metabolic process; IBA:GO_Central.
DR GO; GO:0006704; P:glucocorticoid biosynthetic process; IBA:GO_Central.
DR Gene3D; 1.10.630.10; -; 1.
DR InterPro; IPR033283; CYP11A1.
DR InterPro; IPR001128; Cyt_P450.
DR InterPro; IPR017972; Cyt_P450_CS.
DR InterPro; IPR002401; Cyt_P450_E_grp-I.
DR InterPro; IPR036396; Cyt_P450_sf.
DR PANTHER; PTHR24279:SF3; PTHR24279:SF3; 1.
DR Pfam; PF00067; p450; 1.
DR PRINTS; PR00463; EP450I.
DR PRINTS; PR00385; P450.
DR SUPFAM; SSF48264; SSF48264; 1.
DR PROSITE; PS00086; CYTOCHROME_P450; 1.
PE 3: Inferred from homology;
KW Cholesterol metabolism; Heme; Iron; Lipid metabolism; Membrane;
KW Metal-binding; Mitochondrion; Mitochondrion inner membrane; Monooxygenase;
KW Oxidoreductase; Reference proteome; Steroid metabolism; Steroidogenesis;
KW Sterol metabolism; Transit peptide.
FT TRANSIT 1..39
FT /note="Mitochondrion"
FT /evidence="ECO:0000250|UniProtKB:P00189"
FT CHAIN 40..520
FT /note="Cholesterol side-chain cleavage enzyme,
FT mitochondrial"
FT /id="PRO_0000003584"
FT REGION 19..47
FT /note="Disordered"
FT /evidence="ECO:0000256|SAM:MobiDB-lite"
FT BINDING 461
FT /ligand="heme"
FT /ligand_id="ChEBI:CHEBI:30413"
FT /ligand_part="Fe"
FT /ligand_part_id="ChEBI:CHEBI:18248"
FT /note="axial binding residue"
FT /evidence="ECO:0000250|UniProtKB:P05108"
SQ SEQUENCE 520 AA; 60314 MW; B8420BF587850192 CRC64;
MLVRGLPLRS VLVKGCQPLL SAPREGPGHP RVPTGEGAGM SSHSPRPFKE IPSPGDNGWI
NLYHFWREKG PKKLHYHHFQ NFQKYGPIYR EKLGNVESVY IVDPEDVALL FKFEGPHPER
FLIPPWTAYH QYFQKPVGVL FKSSDAWKKD RLALNPEVMA LESIKNFIPL LDPVSQDFVS
LLHRRMEQQG SGKFSGPIIE DLFRFAFESI TNVIFGERQG MLDEIVDPEA QRFIDAVYKM
FHTSVPMLSL PPDLFRLFRT KTWRDHVAAW DTVFSKAEQY TEKFYQDLKQ KRHFDSYPGI
FYRLLASNKL PFKDIQANVT EMLAGGVDTT SMSLQWHLYE IARNLRVQEM LREEVLAARR
QAQGDTSTMV QMVPLLKASI KETLRLHPIA VTLQRYPQND LVIRDYMIPA KTLVQVSIYT
MGQDPTFFSN PRRFDPTRWL DKNKDLTHFR NLGFGWGVRQ CLGRRIAELE MTLFLIHILE
NFRVEIQHLN DVDSTFGLIL IPEKPISFTF WPITRAPPQA