KEGG   PATHWAY: prj00020
Entry
prj00020                    Pathway                                
Name
Citrate cycle (TCA cycle) - Providencia rustigianii
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
prj00020  Citrate cycle (TCA cycle)
prj00020

Module
prj_M00003  Gluconeogenesis, oxaloacetate => fructose-6P [PATH:prj00020]
prj_M00009  Citrate cycle (TCA cycle, Krebs cycle) [PATH:prj00020]
prj_M00010  Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:prj00020]
prj_M00011  Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:prj00020]
prj_M00307  Pyruvate oxidation, pyruvate => acetyl-CoA [PATH:prj00020]
Other DBs
GO: 0006099
Organism
Providencia rustigianii [GN:prj]
Gene
NCTC6933_01101  gltA; Citrate synthase [KO:K01647] [EC:2.3.3.1]
NCTC6933_01986  acnA; Aconitate hydratase 1 [KO:K01681] [EC:4.2.1.3]
NCTC6933_02731  acnB; Aconitate hydratase 2 [KO:K01682] [EC:4.2.1.3 4.2.1.99]
NCTC6933_02169  icd; Isocitrate dehydrogenase [NADP] [KO:K00031] [EC:1.1.1.42]
NCTC6933_01106  sucA; 2-oxoglutarate dehydrogenase E1 component [KO:K00164] [EC:1.2.4.2]
NCTC6933_01107  sucB; Dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex [KO:K00658] [EC:2.3.1.61]
NCTC6933_02734  lpdA; Dihydrolipoyl dehydrogenase [KO:K00382] [EC:1.8.1.4]
NCTC6933_01109  sucD; Succinyl-CoA ligase [ADP-forming] subunit alpha [KO:K01902] [EC:6.2.1.5]
NCTC6933_01108  sucC; Succinyl-CoA ligase [ADP-forming] subunit beta [KO:K01903] [EC:6.2.1.5]
NCTC6933_01104  sdhA; Succinate dehydrogenase flavoprotein subunit [KO:K00239] [EC:1.3.5.1]
NCTC6933_01105  sdhB; Succinate dehydrogenase iron-sulfur subunit [KO:K00240] [EC:1.3.5.1]
NCTC6933_01103  sdhD; Succinate dehydrogenase hydrophobic membrane anchor subunit [KO:K00242]
NCTC6933_03418  frdA_1; Fumarate reductase flavoprotein subunit [KO:K00244] [EC:1.3.5.1]
NCTC6933_03420  frdB; Fumarate reductase iron-sulfur subunit [KO:K00245] [EC:1.3.5.1]
NCTC6933_03421  frdC; Fumarate reductase 15 kDa hydrophobic protein [KO:K00246]
NCTC6933_03422  frdD; Fumarate reductase 13 kDa hydrophobic protein [KO:K00247]
NCTC6933_03492  fumB; Fumarate hydratase class I, anaerobic [KO:K01676] [EC:4.2.1.2]
NCTC6933_01959  fumC; Fumarate hydratase class II [KO:K01679] [EC:4.2.1.2]
NCTC6933_03652  mdh; Malate dehydrogenase [KO:K00024] [EC:1.1.1.37]
NCTC6933_03676  mqo; Malate:quinone oxidoreductase [KO:K00116] [EC:1.1.5.4]
NCTC6933_00100  pckA; Phosphoenolpyruvate carboxykinase [ATP] [KO:K01610] [EC:4.1.1.49]
NCTC6933_02736  aceE; Pyruvate dehydrogenase E1 component [KO:K00163] [EC:1.2.4.1]
NCTC6933_02735  aceF; Dihydrolipoyllysine-residue acetyltransferase component of pyruvate dehydrogenase complex [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
prj00010  Glycolysis / Gluconeogenesis
prj00053  Ascorbate and aldarate metabolism
prj00061  Fatty acid biosynthesis
prj00071  Fatty acid degradation
prj00190  Oxidative phosphorylation
prj00220  Arginine biosynthesis
prj00250  Alanine, aspartate and glutamate metabolism
prj00280  Valine, leucine and isoleucine degradation
prj00350  Tyrosine metabolism
prj00470  D-Amino acid metabolism
prj00630  Glyoxylate and dicarboxylate metabolism
KO pathway
ko00020   
LinkDB

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