KEGG   PATHWAY: hds00020
Entry
hds00020                    Pathway                                
Name
Citrate cycle (TCA cycle) - Halapricum desulfuricans
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
hds00020  Citrate cycle (TCA cycle)
hds00020

Module
hds_M00010  Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:hds00020]
hds_M00307  Pyruvate oxidation, pyruvate => acetyl-CoA [PATH:hds00020]
Other DBs
GO: 0006099
Organism
Halapricum desulfuricans [GN:hds]
Gene
HSR122_0280  gltA; Citrate synthase [KO:K01647] [EC:2.3.3.1]
HSR122_1961  gltA2; Citrate synthase [KO:K01647] [EC:2.3.3.1]
HSR122_2516  acnA; Aconitase A [KO:K01681] [EC:4.2.1.3]
HSR122_2035  icd; Isocitrate dehydrogenase [KO:K00031] [EC:1.1.1.42]
HSR122_0531  aceF; Pyruvate/2-oxoglutarate dehydrogenase complex, dihydrolipoamide acyltransferase (E2) component or related enzyme [KO:K00382] [EC:1.8.1.4]
HSR122_2700  porA3; Pyruvate:ferredoxin oxidoreductase or related 2-oxoacid:ferredoxin oxidoreductase, alpha subunit and gamma [KO:K00174] [EC:1.2.7.3 1.2.7.11]
HSR122_2701  porB3; Pyruvate:ferredoxin oxidoreductase or related 2-oxoacid:ferredoxin oxidoreductase, beta subunit [KO:K00175] [EC:1.2.7.3 1.2.7.11]
HSR122_0487  sucD; Succinyl-CoA synthetase, alpha subunit [KO:K01902] [EC:6.2.1.5]
HSR122_0486  sucC; Succinyl-CoA synthetase, beta subunit [KO:K01903] [EC:6.2.1.5]
HSR122_1221  sdhA; Succinate dehydrogenase/fumarate reductase, flavoprotein subunit [KO:K00239] [EC:1.3.5.1]
HSR122_1218  sdhB; Succinate dehydrogenase/fumarate reductase, Fe-Sprotein subunit [KO:K00240] [EC:1.3.5.1]
HSR122_1216  sdhC; Succinate dehydrogenase/fumarate reductase, cytochrome b subunit [KO:K00241]
HSR122_1217  sdhD; Succinate dehydrogenase, hydrophobic anchor subunit [KO:K00242]
HSR122_1997  fumC; Fumarase [KO:K01679] [EC:4.2.1.2]
HSR122_0854  porA; Pyruvate:ferredoxin oxidoreductase or related 2-oxoacid:ferredoxin oxidoreductase, alpha subunit [KO:K00169] [EC:1.2.7.1]
HSR122_2320  porA2; Pyruvate:ferredoxin oxidoreductase or related 2-oxoacid:ferredoxin oxidoreductase, alpha subunit and gamma [KO:K00169] [EC:1.2.7.1]
HSR122_0853  porB; Pyruvate:ferredoxin oxidoreductase or related 2-oxoacid:ferredoxin oxidoreductase, beta subunit [KO:K00170] [EC:1.2.7.1]
HSR122_2319  porB2; Pyruvate:ferredoxin oxidoreductase or related 2-oxoacid:ferredoxin oxidoreductase, beta subunit [KO:K00170] [EC:1.2.7.1]
HSR122_0856  porG; Pyruvate:ferredoxin oxidoreductase or related 2-oxoacid:ferredoxin oxidoreductase, gamma subunit [KO:K00172] [EC:1.2.7.1]
HSR122_0855  porD; Pyruvate:ferredoxin oxidoreductase or related 2-oxoacid:ferredoxin 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
hds00010  Glycolysis / Gluconeogenesis
hds00061  Fatty acid biosynthesis
hds00071  Fatty acid degradation
hds00190  Oxidative phosphorylation
hds00220  Arginine biosynthesis
hds00250  Alanine, aspartate and glutamate metabolism
hds00280  Valine, leucine and isoleucine degradation
hds00350  Tyrosine metabolism
hds00470  D-Amino acid metabolism
hds00630  Glyoxylate and dicarboxylate metabolism
KO pathway
ko00020   
LinkDB

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