KEGG   PATHWAY: mox00020
Entry
mox00020                    Pathway                                
Name
Citrate cycle (TCA cycle) - Candidatus Methylomirabilis oxygeniifera
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
mox00020  Citrate cycle (TCA cycle)
mox00020

Module
mox_M00003  Gluconeogenesis, oxaloacetate => fructose-6P [PATH:mox00020]
mox_M00010  Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:mox00020]
mox_M00307  Pyruvate oxidation, pyruvate => acetyl-CoA [PATH:mox00020]
Other DBs
GO: 0006099
Organism
Candidatus Methylomirabilis oxygeniifera [GN:mox]
Gene
DAMO_2812  gltA; citrate synthase [KO:K01647] [EC:2.3.3.1]
DAMO_0386  Aconitate hydratase [KO:K01681] [EC:4.2.1.3]
DAMO_1997  icd; Isocitrate dehydrogenase [NADP] (IDH) (Oxalosuccinate decarboxylase) (NADP(+)-specific ICDH) (IDP) [KO:K00031] [EC:1.1.1.42]
DAMO_1595  lpD; Dihydrolipoyl dehydrogenase (E3 component of pyruvate and 2-oxoglutarate dehydrogenases complexes) (Dihydrolipoamide dehydrogenase) [KO:K00382] [EC:1.8.1.4]
DAMO_1619  korA; 2-oxoglutarate ferredoxin oxidoreductase alpha subunit [KO:K00174] [EC:1.2.7.3 1.2.7.11]
DAMO_1620  2-oxoglutarate ferredoxin oxidoreductase subunit beta [KO:K00175] [EC:1.2.7.3 1.2.7.11]
DAMO_1442  sucD; succinyl-CoA synthetase, alpha subunit, NAD(P)-binding [KO:K01902] [EC:6.2.1.5]
DAMO_1443  sucC; succinyl-CoA synthetase, beta subunit [KO:K01903] [EC:6.2.1.5]
DAMO_1993  sdhA; Succinate dehydrogenase flavoprotein subunit [KO:K00239] [EC:1.3.5.1]
DAMO_1992  Succinate dehydrogenase subunit B [KO:K00240] [EC:1.3.5.1]
DAMO_1996  mdh; malate dehydrogenase [KO:K00024] [EC:1.1.1.37]
DAMO_2938  pckG; Phosphoenolpyruvate carboxykinase [GTP] (PEP carboxykinase) (Phosphoenolpyruvate carboxylase) (PEPCK) [KO:K01596] [EC:4.1.1.32]
DAMO_1598  pdhA; Pyruvate dehydrogenase E1 component, alpha subunit [KO:K00161] [EC:1.2.4.1]
DAMO_1597  pdhB; Pyruvate dehydrogenase E1 component subunit beta [KO:K00162] [EC:1.2.4.1]
DAMO_1596  pdhC; Dihydrolipoyllysine-residue acetyltransferase component of pyruvate dehydrogenase complex (E2) (Dihydrolipoamide acetyltransferase component of pyruvate dehydrogenase complex) [KO:K00627] [EC:2.3.1.12]
DAMO_0981  Thiamine pyrophosphate enzyme domain protein TPP-binding [KO:K00170] [EC:1.2.7.1]
DAMO_0980  Pyruvate flavodoxin/ferredoxin oxidoreductase domain protein [KO:K03737] [EC:1.2.7.1 1.2.7.-]
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
mox00010  Glycolysis / Gluconeogenesis
mox00053  Ascorbate and aldarate metabolism
mox00061  Fatty acid biosynthesis
mox00071  Fatty acid degradation
mox00190  Oxidative phosphorylation
mox00220  Arginine biosynthesis
mox00250  Alanine, aspartate and glutamate metabolism
mox00280  Valine, leucine and isoleucine degradation
mox00350  Tyrosine metabolism
mox00470  D-Amino acid metabolism
mox00630  Glyoxylate and dicarboxylate metabolism
KO pathway
ko00020   
LinkDB

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