KEGG   ENZYME: 1.14.13.97Help
Entry
EC 1.14.13.97               Enzyme                                 

Name
taurochenodeoxycholate 6alpha-hydroxylase;
CYP3A4;
CYP4A21;
taurochenodeoxycholate 6alpha-monooxygenase
Class
Oxidoreductases;
Acting on paired donors, with incorporation or reduction of molecular oxygen;
With NADH or NADPH as one donor, and incorporation of one atom of oxygen into the other donor
BRITE hierarchy
Sysname
taurochenodeoxycholate,NADPH:oxygen oxidoreductase (6alpha-hydroxylating)
Reaction(IUBMB)
(1) taurochenodeoxycholate + NADPH + H+ + O2 = taurohyocholate + NADP+ + H2O [RN:R07205];
(2) lithocholate + NADPH + H+ + O2 = hyodeoxycholate + NADP+ + H2O [RN:R07206]
Reaction(KEGG)
Substrate
taurochenodeoxycholate [CPD:C05465];
NADPH [CPD:C00005];
H+ [CPD:C00080];
O2 [CPD:C00007];
lithocholate [CPD:C03990]
Product
taurohyocholate [CPD:C15516];
NADP+ [CPD:C00006];
H2O [CPD:C00001];
hyodeoxycholate [CPD:C15517]
Comment
A heme-thiolate protein (P-450). Requires cytochrome b5 for maximal activity. Acts on taurochenodeoxycholate, taurodeoxycholate and less readily on lithocholate and chenodeoxycholate. In adult pig (Sus scrofa), hyocholic acid replaces cholic acid as a primary bile acid [5].
History
EC 1.14.13.97 created 2005
Orthology
K17689  
cytochrome P450, family 3, subfamily A, polypeptide 4
K18228  
taurochenodeoxycholate 6alpha-hydroxylase
Genes
HSA: 
1576(CYP3A4)
PTR: 
463582(CYP3A4)
PPS: 
GGO: 
PON: 
NLE: 
MCC: 
678670(CYP3A4)
MCF: 
102144258(CYP3A8)
CSAB: 
RRO: 
TUP: 
CFA: 
479740(CYP3A4)
SSC: 
403327(CYP4A21)
 » show all
Taxonomy
Reference
1  [PMID:10216279]
  Authors
Araya Z, Wikvall K.
  Title
6alpha-hydroxylation of taurochenodeoxycholic acid and lithocholic acid by CYP3A4 in human liver microsomes.
  Journal
Biochim. Biophys. Acta. 1438 (1999) 47-54.
  Sequence
[hsa:1576]
Reference
2  [PMID:7649186]
  Authors
Araya Z, Hellman U, Hansson R.
  Title
Characterisation of taurochenodeoxycholic acid 6 alpha-hydroxylase from pig liver microsomes.
  Journal
Eur. J. Biochem. 231 (1995) 855-61.
  Sequence
[ssc:403327]
Reference
3  [PMID:11069906]
  Authors
Kramer W, Sauber K, Baringhaus KH, Kurz M, Stengelin S, Lange G, Corsiero D, Girbig F, Konig W, Weyland C.
  Title
Identification of the bile acid-binding site of the ileal lipid-binding protein by photoaffinity labeling, matrix-assisted laser desorption ionization-mass spectrometry, and NMR structure.
  Journal
J. Biol. Chem. 276 (2001) 7291-301.
Reference
4  [PMID:11113117]
  Authors
Lundell K, Hansson R, Wikvall K.
  Title
Cloning and expression of a pig liver taurochenodeoxycholic acid 6alpha-hydroxylase (CYP4A21): a novel member of the CYP4A subfamily.
  Journal
J. Biol. Chem. 276 (2001) 9606-12.
  Sequence
[ssc:403327]
Reference
5  [PMID:14643796]
  Authors
Lundell K, Wikvall K.
  Title
Gene structure of pig sterol 12alpha-hydroxylase (CYP8B1) and expression in fetal liver: comparison with expression of taurochenodeoxycholic acid 6alpha-hydroxylase (CYP4A21).
  Journal
Biochim. Biophys. Acta. 1634 (2003) 86-96.
Reference
6  [PMID:12543708]
  Authors
Russell DW.
  Title
The enzymes, regulation, and genetics of bile acid synthesis.
  Journal
Annu. Rev. Biochem. 72 (2003) 137-74.
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 
CAS: 
105669-85-0

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