KEGG   PATHWAY: baq00020Help
baq00020                    Pathway                                

Citrate cycle (TCA cycle) - Bacillus velezensis CAU B946
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
baq00020  Citrate cycle (TCA cycle)

Ortholog table
baq_M00003  Gluconeogenesis, oxaloacetate => fructose-6P [PATH:baq00020]
baq_M00009  Citrate cycle (TCA cycle, Krebs cycle) [PATH:baq00020]
baq_M00010  Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:baq00020]
baq_M00011  Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:baq00020]
baq_M00307  Pyruvate oxidation, pyruvate => acetyl-CoA [PATH:baq00020]
Other DBs
BSID: 553224
GO: 0006099
Bacillus velezensis CAU B946 [GN:baq]
BACAU_0930  citA; citrate synthase I [KO:K01647] [EC:]
BACAU_2635  citZ; citrate synthase [KO:K01647] [EC:]
BACAU_2255  mmgD; citrate synthase 3 [KO:K01647] [EC:]
BACAU_1739  acnA; aconitate hydratase 1 [KO:K01681] [EC:]
BACAU_2634  icd; isocitrate dehydrogenase [KO:K00031] [EC:]
BACAU_1913  sucA; 2-oxoglutarate dehydrogenase E1 component [KO:K00164] [EC:]
BACAU_1912  odhB; dihydrolipoamide succinyltransferase [KO:K00658] [EC:]
BACAU_1419  pdhD; dihydrolipoamide dehydrogenase [KO:K00382] [EC:]
BACAU_2247  dld; dihydrolipoamide dehydrogenase [KO:K00382] [EC:]
BACAU_0809  acoL; dihydrolipoamide dehydrogenase [KO:K00382] [EC:]
BACAU_1564  sucD; succinyl-CoA synthetase subunit alpha [KO:K01902] [EC:]
BACAU_1563  sucC; succinyl-CoA synthetase subunit beta [KO:K01903] [EC:]
BACAU_2567  sdhA; succinate dehydrogenase flavoprotein subunit [KO:K00239] [EC:]
BACAU_2566  sdhB; succinate dehydrogenase iron-sulfur subunit [KO:K00240] [EC:]
BACAU_2568  sdhC; succinate dehydrogenase cytochrome b-556 subunit [KO:K00241]
BACAU_3040  fumC; fumarate hydratase [KO:K01679] [EC:]
BACAU_2633  mdh; malate dehydrogenase [KO:K00024] [EC:]
BACAU_1443  pyc; pyruvate carboxylase subunit A [KO:K01958] [EC:]
BACAU_2770  pckA; phosphoenolpyruvate carboxykinase [KO:K01610] [EC:]
BACAU_1416  pdhA; pyruvate dehydrogenase E1 component subunit alpha [KO:K00161] [EC:]
BACAU_1417  pdhB; pyruvate dehydrogenase E1 component subunit beta [KO:K00162] [EC:]
BACAU_1418  pdhC; branched-chain alpha-keto acid dehydrogenase subunit E2 [KO:K00627] [EC:]
BACAU_0808  acoC; branched-chain alpha-keto acid dehydrogenase subunit E2 [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)
KO pathway

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