KEGG   PATHWAY: thel00020
Entry
thel00020                   Pathway                                
Name
Citrate cycle (TCA cycle) - Infirmifilum lucidum
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
thel00020  Citrate cycle (TCA cycle)
thel00020

Module
thel_M00003  Gluconeogenesis, oxaloacetate => fructose-6P [PATH:thel00020]
thel_M00307  Pyruvate oxidation, pyruvate => acetyl-CoA [PATH:thel00020]
Other DBs
GO: 0006099
Organism
Infirmifilum lucidum [GN:thel]
Gene
IG193_03005  2-oxoacid:acceptor oxidoreductase subunit alpha [KO:K00174] [EC:1.2.7.3 1.2.7.11]
IG193_03000  2-oxoacid:ferredoxin oxidoreductase subunit beta [KO:K00175] [EC:1.2.7.3 1.2.7.11]
IG193_05130  sucD; succinate--CoA ligase subunit alpha [KO:K01902] [EC:6.2.1.5]
IG193_05135  succinate--CoA ligase subunit beta [KO:K01903] [EC:6.2.1.5]
IG193_01760  succinate dehydrogenase/fumarate reductase iron-sulfur subunit [KO:K00240] [EC:1.3.5.1]
IG193_01765  succinate dehydrogenase [KO:K00241]
IG193_01770  hypothetical protein [KO:K00242]
IG193_08250  phosphoenolpyruvate carboxykinase (ATP) [KO:K01610] [EC:4.1.1.49]
IG193_04995  porA; pyruvate ferredoxin oxidoreductase [KO:K00169] [EC:1.2.7.1]
IG193_04825  pyruvate synthase subunit beta [KO:K00170] [EC:1.2.7.1]
IG193_04990  pyruvate ferredoxin oxidoreductase [KO:K00170] [EC:1.2.7.1]
IG193_04810  2-oxoacid:acceptor oxidoreductase family protein [KO:K00172] [EC:1.2.7.1]
IG193_05005  2-oxoacid:acceptor oxidoreductase family protein [KO:K00172] [EC:1.2.7.1]
IG193_04815  4Fe-4S binding protein [KO:K00171] [EC:1.2.7.1]
IG193_05000  4Fe-4S binding protein [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
thel00010  Glycolysis / Gluconeogenesis
thel00053  Ascorbate and aldarate metabolism
thel00061  Fatty acid biosynthesis
thel00071  Fatty acid degradation
thel00190  Oxidative phosphorylation
thel00220  Arginine biosynthesis
thel00250  Alanine, aspartate and glutamate metabolism
thel00280  Valine, leucine and isoleucine degradation
thel00630  Glyoxylate and dicarboxylate metabolism
KO pathway
ko00020   
LinkDB

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