Protein: 7-alpha-hydroxycholest-4-en-3-one 12-alpha-hydroxylase (EC 1.14.14.139) (7-alpha-hydroxy-4-cholesten-3-one 12-alpha-hydroxylase) (CYPVIIIB1) (Cytochrome P450 8B1) (Sterol 12-alpha-hydroxylase) (Q9UNU6)
Organism: Homo sapiens (Human)
Function: A cytochrome P450 monooxygenase involved in primary bile acid biosynthesis. Catalyzes the 12alpha-hydroxylation of 7alpha-hydroxy-4-cholesten-3-one, an intermediate metabolite in cholic acid biosynthesis. Controls biliary balance of cholic acid and chenodeoxycholic acid, ultimately regulating the intestinal absorption of dietary lipids (By similarity). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (CPR; NADPH--hemoprotein reductase) (By similarity).
Subcellular location: Endoplasmic reticulum membrane {ECO:0000250|UniProtKB:O02766}; Single-pass membrane protein {ECO:0000255}. Microsome membrane {ECO:0000250|UniProtKB:O02766}; Single-pass membrane protein {ECO:0000255}.
Sequence: MVLWGPVLGALLVVIAGYLCLPGMLRQRRPWEPPLDKGTVPWLGHAMAFRKNMFEFLKRMRTKHGDVFTVQLGGQYFTFVMDPLSFGSILKDTQRKLDFGQYAKKLVLKVFGYRSVQGDHEMIHSASTKHLRGDGLKDLNETMLDSLSFVMLTSKGWSLDASCWHEDSLFRFCYYILFTAGYLSLFGYTKDKEQDLLQAGELFMEFRKFDLLFPRFVYSLLWPREWLEVGRLQRLFHKMLSVSHSQEKEGISNWLGNMLQFLREQGVPSAMQDKFNFMMLWASQGNTGPTSFWALLYLLKHPEAIRAVREEATQVLGEARLETKQSFAFKLGALQHTPVLDSVVEETLRLRAAPTLLRLVHEDYTLKMSSGQEYLFRHGDILALFPYLSVHMDPDIHPEPTVFKYDRFLNPNGSRKVDFFKTGKKIHHYTMPWGSGVSICPGRFFALSEVKLFILLMVTHFDLELVDPDTPLPHVDPQRWGFGTMQPSHDVRFRYRLHPTE
InterPro domains: - IPR036396: Cytochrome P450 superfamily (homologous_superfamily) [21-498]
- IPR001128: Cytochrome P450 (family) [37-491]
- IPR024204: Cytochrome P450, cholesterol 7-alpha-monooxygenase-type (family) [1-500]
- IPR030686: Cytochrome P450 8B1 (family) [1-501]
- IPR002403: Cytochrome P450, E-class, group IV (family) [33-458]
Interaction partners: - 3 beta-hydroxysteroid dehydrogenase type 7
- Aldo-keto reductase family 1 member D1
- Nuclear receptor subfamily 0 group B member 2
- Sterol 26-hydroxylase, mitochondrial
- Aldo-keto reductase family 1 member C4
- Nuclear receptor subfamily 5 group A member 2
- Bile acid receptor
- Beta-klotho
- Bile salt export pump
- Hepatic sodium/bile acid cotransporter
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:0008395 (steroid hydroxylase activity)
Biological Process (BP): GO:0008150 (biological process), GO:0008152 (metabolic process), GO:0009987 (cellular process), GO:0009058 (biosynthetic process), GO:0044237 (cellular metabolic process), GO:0071704 (organic substance metabolic process), GO:0044281 (small molecule metabolic process), GO:0044238 (primary metabolic process), GO:1901615 (organic hydroxy compound metabolic process), GO:0044249 (cellular biosynthetic process), GO:1901360 (organic cyclic compound metabolic process), GO:1901576 (organic substance biosynthetic process), GO:0006629 (lipid metabolic process), GO:0044283 (small molecule biosynthetic process), GO:0006082 (organic acid metabolic process), GO:1901617 (organic hydroxy compound biosynthetic process), GO:1901362 (organic cyclic compound biosynthetic process), GO:0043436 (oxoacid metabolic process), GO:0016053 (organic acid biosynthetic process), GO:0008206 (bile acid metabolic process), GO:0008202 (steroid metabolic process), GO:0008610 (lipid biosynthetic process), GO:0019752 (carboxylic acid metabolic process), GO:0046394 (carboxylic acid biosynthetic process), GO:0006699 (bile acid biosynthetic process), GO:0006694 (steroid biosynthetic process), GO:0072330 (monocarboxylic acid biosynthetic process), GO:0032787 (monocarboxylic acid metabolic process)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0005622 (intracellular anatomical structure), GO:0043226 (organelle), GO:0016020 (membrane), GO:0005737 (cytoplasm), GO:0012505 (endomembrane system), GO:0031984 (organelle subcompartment), GO:0042175 (nuclear outer membrane-endoplasmic reticulum membrane network), GO:0031090 (organelle membrane), GO:0005783 (endoplasmic reticulum), GO:0043229 (intracellular organelle), GO:0043227 (membrane-bounded organelle), GO:0098827 (endoplasmic reticulum subcompartment), GO:0043231 (intracellular membrane-bounded organelle), GO:0005789 (endoplasmic reticulum membrane)