KEGG   PATHWAY: cfus00020
Entry
cfus00020                   Pathway                                
Name
Citrate cycle (TCA cycle) - Cystobacter fuscus
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
cfus00020  Citrate cycle (TCA cycle)
cfus00020

Module
cfus_M00009  Citrate cycle (TCA cycle, Krebs cycle) [PATH:cfus00020]
cfus_M00010  Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:cfus00020]
cfus_M00011  Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:cfus00020]
cfus_M00307  Pyruvate oxidation, pyruvate => acetyl-CoA [PATH:cfus00020]
Other DBs
GO: 0006099
Organism
Cystobacter fuscus [GN:cfus]
Gene
CYFUS_005273  hypothetical protein [KO:K01647] [EC:2.3.3.1]
CYFUS_000730  hypothetical protein [KO:K01647] [EC:2.3.3.1]
CYFUS_004539  citrate (Si)-synthase [KO:K01647] [EC:2.3.3.1]
CYFUS_004618  aconitate hydratase [KO:K01681] [EC:4.2.1.3]
CYFUS_001961  aconitate hydratase [KO:K01681] [EC:4.2.1.3]
CYFUS_004556  isocitrate dehydrogenase [KO:K00031] [EC:1.1.1.42]
CYFUS_008746  isocitrate dehydrogenase [KO:K00030] [EC:1.1.1.41]
CYFUS_008454  2-oxoglutarate dehydrogenase subunit E1 [KO:K00164] [EC:1.2.4.2]
CYFUS_008455  dihydrolipoamide succinyltransferase [KO:K00658] [EC:2.3.1.61]
CYFUS_003754  dihydrolipoamide dehydrogenase [KO:K00382] [EC:1.8.1.4]
CYFUS_004561  succinate--CoA ligase subunit alpha [KO:K01902] [EC:6.2.1.5]
CYFUS_004560  succinate--CoA ligase subunit beta [KO:K01903] [EC:6.2.1.5]
CYFUS_004558  succinate dehydrogenase flavoprotein subunit [KO:K00239] [EC:1.3.5.1]
CYFUS_004559  succinate dehydrogenase iron-sulfur protein [KO:K00240] [EC:1.3.5.1]
CYFUS_001427  succinate dehydrogenase [KO:K00241]
CYFUS_000684  fumarate hydratase class I [KO:K01676] [EC:4.2.1.2]
CYFUS_008849  class II fumarate hydratase [KO:K01679] [EC:4.2.1.2]
CYFUS_004557  malate dehydrogenase [KO:K00024] [EC:1.1.1.37]
CYFUS_001827  phosphoenolpyruvate carboxykinase [KO:K01596] [EC:4.1.1.32]
CYFUS_003011  Pyruvate dehydrogenase E1 component alpha subunit [KO:K00161] [EC:1.2.4.1]
CYFUS_003012  pyruvate dehydrogenase E1 component subunit beta [KO:K00162] [EC:1.2.4.1]
CYFUS_003013  dihydrolipoamide acetyltransferase component of pyruvate dehydrogenase complex [KO:K00627] [EC:2.3.1.12]
CYFUS_003756  dihydrolipoamide acyltransferase [KO:K00627] [EC:2.3.1.12]
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
cfus00010  Glycolysis / Gluconeogenesis
cfus00053  Ascorbate and aldarate metabolism
cfus00061  Fatty acid biosynthesis
cfus00071  Fatty acid degradation
cfus00190  Oxidative phosphorylation
cfus00220  Arginine biosynthesis
cfus00250  Alanine, aspartate and glutamate metabolism
cfus00280  Valine, leucine and isoleucine degradation
cfus00350  Tyrosine metabolism
cfus00470  D-Amino acid metabolism
cfus00630  Glyoxylate and dicarboxylate metabolism
KO pathway
ko00020   
LinkDB

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