KEGG   PATHWAY: mye00020
Entry
mye00020                    Pathway                                
Name
Citrate cycle (TCA cycle) - Mycobacterium sp. EPa45
Description
The citrate cycle (TCA cycle, Krebs cycle) is an important aerobic pathway for the final steps of the oxidation of carbohydrates and fatty acids. The cycle starts with acetyl-CoA, the activated form of acetate, derived from glycolysis and pyruvate oxidation for carbohydrates and from beta oxidation of fatty acids. The two-carbon acetyl group in acetyl-CoA is transferred to the four-carbon compound of oxaloacetate to form the six-carbon compound of citrate. In a series of reactions two carbons in citrate are oxidized to CO2 and the reaction pathway supplies NADH for use in the oxidative phosphorylation and other metabolic processes. The pathway also supplies important precursor metabolites including 2-oxoglutarate. At the end of the cycle the remaining four-carbon part is transformed back to oxaloacetate. According to the genome sequence data, many organisms seem to lack genes for the full cycle [MD:M00009], but contain genes for specific segments [MD:M00010 M00011].
Class
Metabolism; Carbohydrate metabolism
Pathway map
mye00020  Citrate cycle (TCA cycle)
mye00020

Module
mye_M00003  Gluconeogenesis, oxaloacetate => fructose-6P [PATH:mye00020]
mye_M00009  Citrate cycle (TCA cycle, Krebs cycle) [PATH:mye00020]
mye_M00010  Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:mye00020]
mye_M00011  Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:mye00020]
mye_M00307  Pyruvate oxidation, pyruvate => acetyl-CoA [PATH:mye00020]
Other DBs
GO: 0006099
Organism
Mycobacterium sp. EPa45 [GN:mye]
Gene
AB431_24545  hypothetical protein [KO:K01647] [EC:2.3.3.1]
AB431_13580  acnA; aconitate hydratase [KO:K27802] [EC:4.2.1.3 4.2.1.99]
AB431_07270  isocitrate dehydrogenase [KO:K00031] [EC:1.1.1.42]
AB431_22955  kgd; alpha-ketoglutarate decarboxylase [KO:K01616] [EC:2.2.1.5 4.1.1.71 1.2.4.2 2.3.1.61]
AB431_03635  dihydrolipoyl dehydrogenase [KO:K00382] [EC:1.8.1.4]
AB431_20320  2-oxoglutarate ferredoxin oxidoreductase subunit alpha [KO:K00174] [EC:1.2.7.3 1.2.7.11]
AB431_20315  2-oxoacid:ferredoxin oxidoreductase subunit beta [KO:K00175] [EC:1.2.7.3 1.2.7.11]
AB431_24080  succinyl-CoA synthetase subunit alpha [KO:K01902] [EC:6.2.1.5]
AB431_24085  succinyl-CoA synthetase subunit beta [KO:K01903] [EC:6.2.1.5]
AB431_02045  sdhA; succinate dehydrogenase [KO:K00239] [EC:1.3.5.1]
AB431_07385  fumarate reductase [KO:K00239] [EC:1.3.5.1]
AB431_15615  fumarate reductase [KO:K00239] [EC:1.3.5.1]
AB431_02040  fumarate reductase [KO:K00240] [EC:1.3.5.1]
AB431_07380  succinate dehydrogenase [KO:K00240] [EC:1.3.5.1]
AB431_07395  succinate dehydrogenase [KO:K00241]
AB431_07390  succinate dehydrogenase [KO:K00242]
AB431_06375  aspA; aspartate ammonia-lyase [KO:K01679] [EC:4.2.1.2]
AB431_11255  malate:quinone oxidoreductase [KO:K00116] [EC:1.1.5.4]
AB431_10590  pyruvate carboxylase [KO:K01958] [EC:6.4.1.1]
AB431_01750  phosphoenolpyruvate carboxykinase [KO:K01596] [EC:4.1.1.32]
AB431_19240  pyruvate dehydrogenase [KO:K00163] [EC:1.2.4.1]
AB431_12215  pyruvate dehydrogenase [KO:K00161] [EC:1.2.4.1]
AB431_12210  pyruvate dehydrogenase [KO:K00162] [EC:1.2.4.1]
AB431_12205  branched-chain alpha-keto acid dehydrogenase subunit E2 [KO:K00627] [EC:2.3.1.12]
AB431_18905  hypothetical protein [KO:K00627] [EC:2.3.1.12]
Compound
C00022  Pyruvate
C00024  Acetyl-CoA
C00026  2-Oxoglutarate
C00036  Oxaloacetate
C00042  Succinate
C00068  Thiamin diphosphate
C00074  Phosphoenolpyruvate
C00091  Succinyl-CoA
C00122  Fumarate
C00149  (S)-Malate
C00158  Citrate
C00311  Isocitrate
C00417  cis-Aconitate
C05125  2-(alpha-Hydroxyethyl)thiamine diphosphate
C05379  Oxalosuccinate
C05381  3-Carboxy-1-hydroxypropyl-ThPP
C15972  Enzyme N6-(lipoyl)lysine
C15973  Enzyme N6-(dihydrolipoyl)lysine
C16254  [Dihydrolipoyllysine-residue succinyltransferase] S-succinyldihydrolipoyllysine
C16255  [Dihydrolipoyllysine-residue acetyltransferase] S-acetyldihydrolipoyllysine
Reference
  Authors
Nishizuka Y (ed).
  Title
[Metabolic Maps] (In Japanese)
  Journal
Tokyo Kagaku Dojin (1980)
Reference
  Authors
Nishizuka Y, Seyama Y, Ikai A, Ishimura Y, Kawaguchi A (eds).
  Title
[Cellular Functions and Metabolic Maps] (In Japanese)
  Journal
Tokyo Kagaku Dojin (1997)
Reference
  Authors
Michal G.
  Title
Biochemical Pathways
  Journal
Wiley (1999)
Related
pathway
mye00010  Glycolysis / Gluconeogenesis
mye00053  Ascorbate and aldarate metabolism
mye00061  Fatty acid biosynthesis
mye00071  Fatty acid degradation
mye00190  Oxidative phosphorylation
mye00220  Arginine biosynthesis
mye00250  Alanine, aspartate and glutamate metabolism
mye00280  Valine, leucine and isoleucine degradation
mye00350  Tyrosine metabolism
mye00470  D-Amino acid metabolism
mye00630  Glyoxylate and dicarboxylate metabolism
KO pathway
ko00020   
LinkDB

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