KEGG   PATHWAY: tam00020
Entry
tam00020                    Pathway                                
Name
Citrate cycle (TCA cycle) - Thermovibrio ammonificans
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
tam00020  Citrate cycle (TCA cycle)
tam00020

Module
tam_M00011  Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:tam00020]
tam_M00307  Pyruvate oxidation, pyruvate => acetyl-CoA [PATH:tam00020]
Other DBs
GO: 0006099
Organism
Thermovibrio ammonificans [GN:tam]
Gene
Theam_1021  ATP-citrate lyase/succinyl-CoA ligase [KO:K15230] [EC:2.3.3.8]
Theam_1022  ATP-citrate synthase (ATP-citrate (pro-S-)-lyase)(citrate cleavage enzyme) [KO:K15231] [EC:2.3.3.8]
Theam_1023  isocitrate dehydrogenase, NADP-dependent [KO:K00031] [EC:1.1.1.42]
Theam_1411  pyruvate flavodoxin/ferredoxin oxidoreductase domain protein [KO:K00174] [EC:1.2.7.3 1.2.7.11]
Theam_1378  pyruvate flavodoxin/ferredoxin oxidoreductase domain protein [KO:K00174] [EC:1.2.7.3 1.2.7.11]
Theam_1412  thiamine pyrophosphate TPP-binding domain-containing protein [KO:K00175] [EC:1.2.7.3 1.2.7.11]
Theam_1379  pyruvate ferredoxin/flavodoxin oxidoreductase, beta subunit [KO:K00175] [EC:1.2.7.3 1.2.7.11]
Theam_1413  Pyruvate/ketoisovalerate oxidoreductase, catalytic domain protein [KO:K00177] [EC:1.2.7.3]
Theam_1410  4Fe-4S ferredoxin iron-sulfur binding domain protein [KO:K00176] [EC:1.2.7.3]
Theam_1409  succinyl-CoA synthetase, alpha subunit [KO:K01902] [EC:6.2.1.5]
Theam_1408  succinyl-CoA synthetase, beta subunit [KO:K01903] [EC:6.2.1.5]
Theam_1272  succinate dehydrogenase or fumarate reductase, flavoprotein subunit [KO:K00239] [EC:1.3.5.1]
Theam_1271  succinate dehydrogenase and fumarate reductase iron-sulfur protein [KO:K00240] [EC:1.3.5.1]
Theam_1270  CoB--CoM heterodisulfide reductase [KO:K00241]
Theam_1275  CoB--CoM heterodisulfide reductase [KO:K00241]
Theam_0603  hydro-lyase, Fe-S type, tartrate/fumarate subfamily, alpha subunit [KO:K01677] [EC:4.2.1.2]
Theam_0730  hydro-lyase, Fe-S type, tartrate/fumarate subfamily, beta subunit [KO:K01678] [EC:4.2.1.2]
Theam_0602  malate dehydrogenase, NAD-dependent [KO:K00024] [EC:1.1.1.37]
Theam_1539  acetyl-CoA carboxylase, biotin carboxylase [KO:K01959] [EC:6.4.1.1]
Theam_1540  oxaloacetate decarboxylase alpha subunit [KO:K01960] [EC:6.4.1.1]
Theam_1393  pyruvate flavodoxin/ferredoxin oxidoreductase domain protein [KO:K00169] [EC:1.2.7.1]
Theam_1392  thiamine pyrophosphate TPP-binding domain-containing protein [KO:K00170] [EC:1.2.7.1]
Theam_1395  pyruvate/ketoisovalerate oxidoreductase, gamma subunit [KO:K00172] [EC:1.2.7.1]
Theam_1394  pyruvate ferredoxin/flavodoxin oxidoreductase, delta subunit [KO:K00171] [EC:1.2.7.1]
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
tam00010  Glycolysis / Gluconeogenesis
tam00061  Fatty acid biosynthesis
tam00190  Oxidative phosphorylation
tam00220  Arginine biosynthesis
tam00250  Alanine, aspartate and glutamate metabolism
tam00280  Valine, leucine and isoleucine degradation
tam00350  Tyrosine metabolism
tam00470  D-Amino acid metabolism
tam00630  Glyoxylate and dicarboxylate metabolism
KO pathway
ko00020   
LinkDB

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