KEGG   PATHWAY: aav00020Help
aav00020                    Pathway                                

Citrate cycle (TCA cycle) - Acidovorax citrulli
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].
Metabolism; Carbohydrate metabolism
BRITE hierarchy
Pathway map
aav00020  Citrate cycle (TCA cycle)

Ortholog table
aav_M00003  Gluconeogenesis, oxaloacetate => fructose-6P [PATH:aav00020]
aav_M00009  Citrate cycle (TCA cycle, Krebs cycle) [PATH:aav00020]
aav_M00010  Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:aav00020]
aav_M00011  Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:aav00020]
aav_M00307  Pyruvate oxidation, pyruvate => acetyl-CoA [PATH:aav00020]
Other DBs
GO: 0006099
Acidovorax citrulli [GN:aav]
Aave_2199  citrate synthase [KO:K01647] [EC:]
Aave_1151  aconitase [KO:K01681] [EC:]
Aave_2210  aconitase [KO:K01682] [EC:]
Aave_2572  isocitrate dehydrogenase (NADP) [KO:K00031] [EC:]
Aave_3248  2-oxoglutarate dehydrogenase E1 component [KO:K00164] [EC:]
Aave_3247  2-oxoglutarate dehydrogenase E2 component [KO:K00658] [EC:]
Aave_2433  pyridine nucleotide-disulfide oxidoreductase dimerization region [KO:K00382] [EC:]
Aave_2464  dihydrolipoamide dehydrogenase [KO:K00382] [EC:]
Aave_3246  dihydrolipoamide dehydrogenase [KO:K00382] [EC:]
Aave_4683  succinyl-CoA synthetase (ADP-forming) alpha subunit [KO:K01902] [EC:]
Aave_4684  succinyl-CoA synthetase (ADP-forming) beta subunit [KO:K01903] [EC:]
Aave_0100  Acetyl-CoA hydrolase [KO:K18118] [EC:]
Aave_2202  succinate dehydrogenase subunit A [KO:K00239] [EC:]
Aave_2201  succinate dehydrogenase subunit B [KO:K00240] [EC:]
Aave_2204  succinate dehydrogenase subunit C [KO:K00241]
Aave_2203  succinate dehydrogenase subunit D [KO:K00242]
Aave_1489  fumarase [KO:K01676] [EC:]
Aave_1491  fumarase [KO:K01679] [EC:]
Aave_2206  malate dehydrogenase (NAD) [KO:K00024] [EC:]
Aave_1166  malate--quinone oxidoreductase [KO:K00116] [EC:]
Aave_0138  Phosphoenolpyruvate carboxykinase (GTP) [KO:K01596] [EC:]
Aave_2462  2-oxo-acid dehydrogenase E1 subunit, homodimeric type [KO:K00163] [EC:]
Aave_2463  pyruvate dehydrogenase complex dihydrolipoamide acetyltransferase [KO:K00627] [EC:]
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
(map 2)
Nishizuka Y (ed).
[Metabolic Maps] (In Japanese)
Tokyo Kagaku Dojin (1980)
(map 3)
Nishizuka Y, Seyama Y, Ikai A, Ishimura Y, Kawaguchi A (eds).
[Cellular Functions and Metabolic Maps] (In Japanese)
Tokyo Kagaku Dojin (1997)
Michal G.
Biochemical Pathways
Wiley (1999)
aav00010  Glycolysis / Gluconeogenesis
aav00053  Ascorbate and aldarate metabolism
aav00061  Fatty acid biosynthesis
aav00071  Fatty acid degradation
aav00220  Arginine biosynthesis
aav00250  Alanine, aspartate and glutamate metabolism
aav00280  Valine, leucine and isoleucine degradation
aav00350  Tyrosine metabolism
aav00471  D-Glutamine and D-glutamate metabolism
aav00630  Glyoxylate and dicarboxylate metabolism
KO pathway

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