KEGG   PATHWAY: ko00120
Entry
ko00120                     Pathway                                
Name
Primary bile acid biosynthesis
Description
Bile acids are steroid carboxylic acids derived from cholesterol in vertebrates. The primary bile acids, cholic acid and chenodeoxycholic acid, are synthesized in the liver and conjugated with taurine or glycine before secretion via bile into the intestine. The conversion from cholesterol to cholic and chenodeoxycholic acids involves four steps: 1) the initiation of synthesis by 7alpha-hydroxylation of sterol precursors, 2) further modifications to the ring structures, 3) side-chain oxidation and shortening (cleavage) by three carbons, and 4) conjugation of the bile acid with taurine or glycine.
Class
Metabolism; Lipid metabolism
Pathway map
ko00120  Primary bile acid biosynthesis
ko00120

Module
M00104  Bile acid biosynthesis, cholesterol => cholate/chenodeoxycholate [PATH:ko00120]
M00106  Conjugated bile acid biosynthesis, cholate => taurocholate/glycocholate [PATH:ko00120]
M00862  beta-Oxidation, peroxisome, tri/dihydroxycholestanoyl-CoA => choloyl/chenodeoxycholoyl-CoA [PATH:ko00120]
Orthology
K07440  cholesterol 24-hydroxylase [EC:1.14.14.25]
K07439  24-hydroxycholesterol 7alpha-hydroxylase [EC:1.14.14.26]
K12408  cholest-5-ene-3beta,7alpha-diol 3beta-dehydrogenase [EC:1.1.1.181]
K10223  cholesterol 25-hydroxylase [EC:1.14.99.38]
K07430  25/26-hydroxycholesterol 7alpha-hydroxylase [EC:1.14.14.29]
K00489  cholesterol 7alpha-monooxygenase [EC:1.14.14.23]
K00488  cholestanetriol 26-monooxygenase [EC:1.14.15.15]
K07431  sterol 12-alpha-hydroxylase [EC:1.14.14.139]
K00251  3-oxo-5-beta-steroid 4-dehydrogenase [EC:1.3.1.3]
K00037  3alpha-hydroxysteroid 3-dehydrogenase / chlordecone reductase [EC:1.1.1.50 1.1.1.357 1.1.1.225]
K08748  solute carrier family 27 (fatty acid transporter), member 5 [EC:6.2.1.7]
K01796  alpha-methylacyl-CoA racemase [EC:5.1.99.4]
K10214  3alpha,7alpha,12alpha-trihydroxy-5beta-cholestanoyl-CoA 24-hydroxylase [EC:1.17.99.3]
K12405  (3R)-3-hydroxyacyl-CoA dehydrogenase / 3a,7a,12a-trihydroxy-5b-cholest-24-enoyl-CoA hydratase / enoyl-CoA hydratase 2 [EC:1.1.1.- 4.2.1.107 4.2.1.119]
K08764  sterol carrier protein 2 [EC:2.3.1.176]
K11992  acyl-CoA thioesterase 8 [EC:3.1.2.27]
K00659  bile acid-CoA:amino acid N-acyltransferase [EC:2.3.1.65 3.1.2.2]
K01442  choloylglycine hydrolase [EC:3.5.1.24]
Compound
C00037  Glycine
C00187  Cholesterol
C00245  Taurine
C00695  Cholic acid
C01301  3alpha,7alpha,12alpha-Trihydroxy-5beta-cholestan-26-al
C01794  Choloyl-CoA
C01921  Glycocholate
C02528  Chenodeoxycholate
C03594  7alpha-Hydroxycholesterol
C04554  3alpha,7alpha-Dihydroxy-5beta-cholestanate
C04722  3alpha,7alpha,12alpha-Trihydroxy-5beta-cholestanoate
C05122  Taurocholate
C05337  Chenodeoxycholoyl-CoA
C05444  3alpha,7alpha,26-Trihydroxy-5beta-cholestane
C05445  3alpha,7alpha-Dihydroxy-5beta-cholestan-26-al
C05446  3alpha,7alpha,12alpha,26-Tetrahydroxy-5beta-cholestane
C05447  (24E)-3alpha,7alpha-Dihydroxy-5beta-cholest-24-enoyl-CoA
C05448  (24R,25R)-3alpha,7alpha,24-Trihydroxy-5beta-cholestanoyl-CoA
C05449  3alpha,7alpha-Dihydroxy-5beta-24-oxocholestanoyl-CoA
C05451  7alpha-Hydroxy-5beta-cholestan-3-one
C05452  3alpha,7alpha-Dihydroxy-5beta-cholestane
C05453  7alpha,12alpha-Dihydroxy-5beta-cholestan-3-one
C05454  3alpha,7alpha,12alpha-Trihydroxy-5beta-cholestane
C05455  7alpha-Hydroxycholest-4-en-3-one
C05460  (24E)-3alpha,7alpha,12alpha-Trihydroxy-5beta-cholest-24-enoyl-CoA
C05465  Taurochenodeoxycholate
C05466  Glycochenodeoxycholate
C05467  3alpha,7alpha,12alpha-Trihydroxy-5beta-24-oxocholestanoyl-CoA
C05468  5beta-Cyprinolsulfate
C06341  7alpha,27-Dihydroxycholesterol
C13550  Cerebrosterol
C15518  (24S)-Cholest-5-ene-3beta,7alpha,24-triol
C15519  25-Hydroxycholesterol
C15520  Cholest-5-ene-3beta,7alpha,25-triol
C15610  Cholest-5-ene-3beta,26-diol
C15613  (25R)-3alpha,7alpha,12alpha-Trihydroxy-5beta-cholestan-26-oyl-CoA
C15614  (24R,25R)-3alpha,7alpha,12alpha,24-Tetrahydroxy-5beta-cholestanoyl-CoA
C17331  7alpha,24-Dihydroxy-4-cholesten-3-one
C17332  7alpha,25-Dihydroxy-4-cholesten-3-one
C17333  3beta-Hydroxy-5-cholestenoate
C17335  3beta,7alpha-Dihydroxy-5-cholestenoate
C17336  7alpha,26-Dihydroxy-4-cholesten-3-one
C17337  7alpha-Hydroxy-3-oxo-4-cholestenoate
C17339  4-Cholesten-7alpha,12alpha-diol-3-one
C17343  (25S)-3alpha,7alpha,12alpha-Trihydroxy-5beta-cholestan-26-oyl-CoA
C17345  (25R)-3alpha,7alpha-Dihydroxy-5beta-cholestanoyl-CoA
C17346  (25S)-3alpha,7alpha-Dihydroxy-5beta-cholestanoyl-CoA
Reference
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
Reference
PMID:17346171
  Authors
Norlin M, Wikvall K
  Title
Enzymes in the conversion of cholesterol into bile acids.
  Journal
Curr Mol Med 7:199-218 (2007)
DOI:10.2174/156652407780059168
Reference
PMID:10198776
  Authors
Vlahcevic ZR, Pandak WM, Stravitz RT
  Title
Regulation of bile acid biosynthesis.
  Journal
Gastroenterol Clin North Am 28:1-25, v (1999)
DOI:10.1016/S0889-8553(05)70041-8
Reference
PMID:18081658
  Authors
Pellicoro A, Faber KN
  Title
Review article: The function and regulation of proteins involved in bile salt biosynthesis and transport.
  Journal
Aliment Pharmacol Ther 26 Suppl 2:149-60 (2007)
DOI:10.1111/j.1365-2036.2007.03522.x
Reference
PMID:18488143
  Authors
Hofmann AF, Hagey LR
  Title
Bile acids: chemistry, pathochemistry, biology, pathobiology, and therapeutics.
  Journal
Cell Mol Life Sci 65:2461-83 (2008)
DOI:10.1007/s00018-008-7568-6
Reference
PMID:11067870
  Authors
Schwarz M, Wright AC, Davis DL, Nazer H, Bjorkhem I, Russell DW
  Title
The bile acid synthetic gene 3beta-hydroxy-Delta(5)-C(27)-steroid oxidoreductase is mutated in progressive intrahepatic cholestasis.
  Journal
J Clin Invest 106:1175-84 (2000)
DOI:10.1172/JCI10902
Reference
PMID:16299351
  Authors
Ridlon JM, Kang DJ, Hylemon PB
  Title
Bile salt biotransformations by human intestinal bacteria.
  Journal
J Lipid Res 47:241-59 (2006)
DOI:10.1194/jlr.R500013-JLR200
Reference
PMID:9292932
  Authors
Bortolini O, Medici A, Poli S
  Title
Biotransformations on steroid nucleus of bile acids.
  Journal
Steroids 62:564-77 (1997)
DOI:10.1016/S0039-128X(97)00043-3
Related
pathway
ko00100  Steroid biosynthesis
ko00121  Secondary bile acid biosynthesis
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