KEGG   PATHWAY: pecq00020
Entry
pecq00020                   Pathway                                
Name
Citrate cycle (TCA cycle) - Pseudonocardia sp. EC080619-01
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
pecq00020  Citrate cycle (TCA cycle)
pecq00020

Module
pecq_M00003  Gluconeogenesis, oxaloacetate => fructose-6P [PATH:pecq00020]
pecq_M00009  Citrate cycle (TCA cycle, Krebs cycle) [PATH:pecq00020]
pecq_M00010  Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:pecq00020]
pecq_M00011  Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:pecq00020]
pecq_M00307  Pyruvate oxidation, pyruvate => acetyl-CoA [PATH:pecq00020]
Other DBs
GO: 0006099
Organism
Pseudonocardia sp. EC080619-01 [GN:pecq]
Gene
AD017_16000  citrate synthase [KO:K01647] [EC:2.3.3.1]
AD017_16020  citrate synthase [KO:K01647] [EC:2.3.3.1]
AD017_06975  citrate (Si)-synthase [KO:K01647] [EC:2.3.3.1]
AD017_10505  hypothetical protein [KO:K01647] [EC:2.3.3.1]
AD017_10520  citrate synthase 2 [KO:K01647] [EC:2.3.3.1]
AD017_27460  hypothetical protein [KO:K01647] [EC:2.3.3.1]
AD017_25090  acnA; aconitate hydratase [KO:K01681] [EC:4.2.1.3]
AD017_17750  isocitrate dehydrogenase [KO:K00031] [EC:1.1.1.42]
AD017_18515  kgd; alpha-ketoglutarate decarboxylase [KO:K01616] [EC:2.2.1.5 4.1.1.71 1.2.4.2 2.3.1.61]
AD017_22725  dihydrolipoamide dehydrogenase [KO:K00382] [EC:1.8.1.4]
AD017_26600  dihydrolipoyl dehydrogenase [KO:K00382] [EC:1.8.1.4]
AD017_16820  2-oxoglutarate ferredoxin oxidoreductase subunit alpha [KO:K00174] [EC:1.2.7.3 1.2.7.11]
AD017_16815  2-oxoacid:ferredoxin oxidoreductase subunit beta [KO:K00175] [EC:1.2.7.3 1.2.7.11]
AD017_17685  succinyl-CoA synthetase subunit alpha [KO:K01902] [EC:6.2.1.5]
AD017_17680  succinyl-CoA synthetase subunit beta [KO:K01903] [EC:6.2.1.5]
AD017_05175  sdhA; succinate dehydrogenase [KO:K00239] [EC:1.3.5.1]
AD017_05190  sdhA; succinate dehydrogenase [KO:K00239] [EC:1.3.5.1]
AD017_05170  fumarate reductase [KO:K00240] [EC:1.3.5.1]
AD017_05185  succinate dehydrogenase [KO:K00240] [EC:1.3.5.1]
AD017_05195  succinate dehydrogenase [KO:K00241]
AD017_03095  fumarate hydratase [KO:K01676] [EC:4.2.1.2]
AD017_09365  aspA; aspartate ammonia-lyase [KO:K01679] [EC:4.2.1.2]
AD017_02390  malate dehydrogenase [KO:K00024] [EC:1.1.1.37]
AD017_06000  pyruvate carboxylase [KO:K01958] [EC:6.4.1.1]
AD017_08090  pyruvate carboxylase [KO:K01958] [EC:6.4.1.1]
AD017_13710  phosphoenolpyruvate carboxykinase [KO:K01596] [EC:4.1.1.32]
AD017_03235  pyruvate dehydrogenase [KO:K00163] [EC:1.2.4.1]
AD017_04945  pyruvate dehydrogenase [KO:K00163] [EC:1.2.4.1]
AD017_22720  dihydrolipoamide acetyltransferase [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
pecq00010  Glycolysis / Gluconeogenesis
pecq00053  Ascorbate and aldarate metabolism
pecq00061  Fatty acid biosynthesis
pecq00071  Fatty acid degradation
pecq00190  Oxidative phosphorylation
pecq00220  Arginine biosynthesis
pecq00250  Alanine, aspartate and glutamate metabolism
pecq00280  Valine, leucine and isoleucine degradation
pecq00350  Tyrosine metabolism
pecq00470  D-Amino acid metabolism
pecq00630  Glyoxylate and dicarboxylate metabolism
KO pathway
ko00020   
LinkDB

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