KEGG ENZYME: 1.14.14.139

ENZYME: 1.14.14.139

Entry

EC 1.14.14.139 Enzyme

Name

5beta-cholestane-3alpha,7alpha-diol 12alpha-hydroxylase;
5beta-cholestane-3alpha,7alpha-diol 12alpha-monooxygenase;
sterol 12alpha-hydroxylase (ambiguous);
CYP8B1;
cytochrome P450 8B1

Class

Oxidoreductases;
Acting on paired donors, with incorporation or reduction of molecular oxygen;
With reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen into the other donor

Sysname

5beta-cholestane-3alpha,7alpha-diol,[reduced NADPH---hemoprotein reductase]:oxygen oxidoreductase (12alpha-hydroxylating)

Reaction(IUBMB)

5beta-cholestane-3alpha,7alpha-diol + [reduced NADPH---hemoprotein reductase] + O2 = 5beta-cholestane-3alpha,7alpha,12alpha-triol + [oxidized NADPH---hemoprotein reductase] + H2O [RN:R07204]

Reaction(KEGG)

R07204

Substrate

5beta-cholestane-3alpha,7alpha-diol [CPD:C05452];
[reduced NADPH---hemoprotein reductase] [CPD:C03024];
O2 [CPD:C00007]

Product

5beta-cholestane-3alpha,7alpha,12alpha-triol [CPD:C05454];
[oxidized NADPH---hemoprotein reductase] [CPD:C03161];
H2O [CPD:C00001]

Comment

A cytochrome P-450 (heme-thiolate) protein found in mammals. This is the key enzyme in the biosynthesis of the bile acid cholic acid (3alpha,7alpha,12alpha-trihydroxy-5beta-cholanoic acid). The activity of this enzyme determines the biosynthetic ratio between cholic acid and chenodeoxycholic acid [3]. The enzyme can also hydroxylate the substrate at the 25 and 26 position, but to a lesser extent [1].

History

EC 1.14.14.139 created 2005 as EC 1.14.13.96, transferred 2018 to EC 1.14.14.139

Pathway

ec00120

Primary bile acid biosynthesis

ec01100

Metabolic pathways

Orthology

K07431

sterol 12-alpha-hydroxylase

Genes

HSA:	1582(CYP8B1)

PTR:	736962(CYP8B1)

PPS:

GGO:

PON:

NLE:

MCC:

MCF:

CSAB:

103227471(CYP8B1)

RRO:

104670956

RBB:

108532333

CJC:	100402181(CYP8B1)

SBQ:

101037790

MMU:	13124(Cyp8b1)

MCAL:

110302470

MPAH:

110327161

RNO:	81924(Cyp8b1)

MUN:

CGE:

NGI:

CCAN:

OCU:	100009301(CYP8B1)

TUP:

CFA:

VVP:

AML:

UMR:

UAH:

ORO:

FCA:

PTG:

AJU:

BTA:	538964(CYP8B1)

BOM:

BIU:

BBUB:

PHD:

CHX:

OAS:

SSC:	403328(CYP8B1)

CFR:

CDK:

BACU:

LVE:

OOR:

DLE:

ECB:

EPZ:

EAI:

MYB:

MYD:

MNA:

HAI:

RSS:

DRO:

PALE:

LAV:

TMU:

MDO:	100026549(CYP8B)

SHR:	100918099 100918355 100918615 100919664 100926550 100926813 105749568 105749630

PCW:

110217059

OAA:

103166427

GGA:	425055(CYP8B1)

MGP:

CJO:

APLA:

ACYG:

TGU:

LSR:

SCAN:

GFR:

FAB:

PHI:

PMAJ:

CCAE:

CCW:

ETL:

FPG:

FCH:

CLV:

EGZ:

NNI:

ACUN:

ASN:

AMJ:	102573091(CYP8B1)

PSS:

102444673

CMY:

102934823

CPIC:

101950173

ACS:	100551676 100551876 100562756 100562953 100565509 100565705 100565905 100566106

PVT:	110091568 110091574 110091575

PBI:	103051222 103065731

PMUR:

107284342 107284343 107284344 107284346 107284348 107284362

GJA:	107106985 107106986 107110695 107112093 107125164

XLA:	108718630 108718631(cyp8b1.L) 379482(cyp8b1.S)

XTR:	100488015 100488168(cyp8b1)

NPR:

108788787

DRE:	445281(cyp8b1)

SRX:	107711691 107727542

SANH:

107661909 107671665

SGH:	107558014 107580338 107593879

CCAR:

109056773 109056779 109056788

IPU:	108261592 108268189 108268197

PHYP:

113524124 113524125

AMEX:

103039627

EEE:	113582944 113590803

TRU:	101070868 101071841 101080232

TNG:	GSTEN00016125G001 GSTEN00016134G001 GSTEN00016135G001

LCO:	104917693 104924020

NCC:	104940932 104941058

MZE:	101474730 106675939 106676194

OLA:

XMA:

XCO:

PRET:

NFU:

KMR:	108241650 108241654

CSEM:

103396384

LCF:	108883349 108893535

SDU:

111231161

HCQ:

109521313

BPEC:

110154953 110159864

SASA:

106569335 106599887 106599889

OTW:	112226785 112226786 112260644

SALP:

111956862

ELS:	105019795 105019804 106024913

SFM:	108919335 108937621

PKI:	111845862 111845867

LCM:	102357417 102361952

CMK:

103188298

PCAN:

112572139

MRR:	Moror_12575

UMA:	UMAG_04362

» show all

Reference

1 [PMID:6811268]

Authors

Hansson R, Wikvall K.

Title

Hydroxylations in biosynthesis of bile acids. Cytochrome P-450 LM4 and 12alpha-hydroxylation of 5beta-cholestane-3alpha, 7alpha-diol.

Journal

Eur J Biochem 125:423-9 (1982)
DOI:10.1111/j.1432-1033.1982.tb06700.x

Reference

2 [PMID:6766451]

Authors

Hansson R, Wikvall K.

Title

Hydroxylations in biosynthesis and metabolism of bile acids. Catalytic properties of different forms of cytochrome P-450.

Journal

J Biol Chem 255:1643-9 (1980)

Reference

3 [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 1634:86-96 (2003)
DOI:10.1016/j.bbalip.2003.09.002

Sequence

[ssc:403328]

Reference

4 [PMID:10747975]

Authors

del Castillo-Olivares A, Gil G.

Title

Alpha 1-fetoprotein transcription factor is required for the expression of sterol 12alpha -hydroxylase, the specific enzyme for cholic acid synthesis. Potential role in the bile acid-mediated regulation of gene transcription.

Journal

J Biol Chem 275:17793-9 (2000)
DOI:10.1074/jbc.M000996200

Reference

5 [PMID:12069850]

Authors

Yang Y, Zhang M, Eggertsen G, Chiang JY.

Title

On the mechanism of bile acid inhibition of rat sterol 12alpha-hydroxylase gene (CYP8B1) transcription: roles of alpha-fetoprotein transcription factor and hepatocyte nuclear factor 4alpha.

Journal

Biochim Biophys Acta 1583:63-73 (2002)
DOI:10.1016/S1388-1981(02)00186-5

Reference

6 [PMID:12543708]

Authors

Russell DW.

Title

The enzymes, regulation, and genetics of bile acid synthesis.

Journal

Annu Rev Biochem 72:137-74 (2003)
DOI:10.1146/annurev.biochem.72.121801.161712

Sequence

[hsa:1582] [mmu:13124]