KEGG   PATHWAY: fca00020
Entry
fca00020                    Pathway                                
Name
Citrate cycle (TCA cycle) - Felis catus (domestic cat)
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
fca00020  Citrate cycle (TCA cycle)
fca00020

Module
fca_M00003  Gluconeogenesis, oxaloacetate => fructose-6P [PATH:fca00020]
fca_M00009  Citrate cycle (TCA cycle, Krebs cycle) [PATH:fca00020]
fca_M00010  Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:fca00020]
fca_M00011  Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:fca00020]
fca_M00307  Pyruvate oxidation, pyruvate => acetyl-CoA [PATH:fca00020]
Other DBs
GO: 0006099
Organism
Felis catus (domestic cat) [GN:fca]
Gene
751515  CS; citrate synthase, mitochondrial isoform X1 [KO:K01647] [EC:2.3.3.1]
100422779  ACLY; ATP-citrate synthase isoform X3 [KO:K01648] [EC:2.3.3.8]
101101395  ACO2; aconitate hydratase, mitochondrial isoform X1 [KO:K01681] [EC:4.2.1.3]
101095526  ACO1; cytoplasmic aconitate hydratase [KO:K01681] [EC:4.2.1.3]
751618  IDH1; isocitrate dehydrogenase [NADP] cytoplasmic [KO:K00031] [EC:1.1.1.42]
101082315  IDH2; isocitrate dehydrogenase [NADP], mitochondrial isoform X1 [KO:K00031] [EC:1.1.1.42]
101099035  IDH3B; isocitrate dehydrogenase [NAD] subunit beta, mitochondrial isoform X1 [KO:K00030] [EC:1.1.1.41]
101085721  IDH3A; isocitrate dehydrogenase [NAD] subunit alpha, mitochondrial isoform X1 [KO:K00030] [EC:1.1.1.41]
102902308  IDH3G; LOW QUALITY PROTEIN: isocitrate dehydrogenase [NAD] subunit gamma, mitochondrial [KO:K00030] [EC:1.1.1.41]
101086177  isocitrate dehydrogenase [NAD] subunit gamma, mitochondrial-like [KO:K00030] [EC:1.1.1.41]
101096048  OGDH; 2-oxoglutarate dehydrogenase, mitochondrial isoform X3 [KO:K00164] [EC:1.2.4.2]
101093146  OGDHL; 2-oxoglutarate dehydrogenase-like, mitochondrial [KO:K00164] [EC:1.2.4.2]
101095266  DLST; dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex, mitochondrial [KO:K00658] [EC:2.3.1.61]
101094004  DLD; dihydrolipoyl dehydrogenase, mitochondrial [KO:K00382] [EC:1.8.1.4]
101084188  SUCLG1; succinate--CoA ligase [ADP/GDP-forming] subunit alpha, mitochondrial isoform X2 [KO:K01899] [EC:6.2.1.4 6.2.1.5]
101096373  SUCLA2; succinate--CoA ligase [ADP-forming] subunit beta, mitochondrial isoform X1 [KO:K01900] [EC:6.2.1.4 6.2.1.5]
101088732  SUCLG2; succinate--CoA ligase [GDP-forming] subunit beta, mitochondrial isoform X1 [KO:K01900] [EC:6.2.1.4 6.2.1.5]
751619  SDHA; succinate dehydrogenase [ubiquinone] flavoprotein subunit, mitochondrial isoform X1 [KO:K00234] [EC:1.3.5.1]
751617  SDHB; succinate dehydrogenase [ubiquinone] iron-sulfur subunit, mitochondrial isoform X1 [KO:K00235] [EC:1.3.5.1]
101087808  SDHC; succinate dehydrogenase cytochrome b560 subunit, mitochondrial isoform X2 [KO:K00236]
101095280  SDHD; succinate dehydrogenase [ubiquinone] cytochrome b small subunit, mitochondrial isoform X1 [KO:K00237]
101096029  FH; fumarate hydratase, mitochondrial [KO:K01679] [EC:4.2.1.2]
493924  MDH1; malate dehydrogenase, cytoplasmic [KO:K00025] [EC:1.1.1.37]
101084845  MDH2; malate dehydrogenase, mitochondrial [KO:K00026] [EC:1.1.1.37]
101089547  PC; pyruvate carboxylase, mitochondrial isoform X2 [KO:K01958] [EC:6.4.1.1]
101089256  PCK1; phosphoenolpyruvate carboxykinase, cytosolic [GTP] [KO:K01596] [EC:4.1.1.32]
101098874  PCK2; phosphoenolpyruvate carboxykinase [GTP], mitochondrial isoform X1 [KO:K01596] [EC:4.1.1.32]
101080765  PDHA1; pyruvate dehydrogenase E1 component subunit alpha, somatic form, mitochondrial [KO:K00161] [EC:1.2.4.1]
101081627  PDHA2; pyruvate dehydrogenase E1 component subunit alpha, testis-specific form, mitochondrial [KO:K00161] [EC:1.2.4.1]
101100374  PDHB; pyruvate dehydrogenase E1 component subunit beta, mitochondrial [KO:K00162] [EC:1.2.4.1]
101094126  DLAT; dihydrolipoyllysine-residue acetyltransferase component of pyruvate dehydrogenase complex, mitochondrial [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
fca00010  Glycolysis / Gluconeogenesis
fca00053  Ascorbate and aldarate metabolism
fca00061  Fatty acid biosynthesis
fca00062  Fatty acid elongation
fca00071  Fatty acid degradation
fca00190  Oxidative phosphorylation
fca00220  Arginine biosynthesis
fca00250  Alanine, aspartate and glutamate metabolism
fca00280  Valine, leucine and isoleucine degradation
fca00350  Tyrosine metabolism
fca00470  D-Amino acid metabolism
fca00630  Glyoxylate and dicarboxylate metabolism
KO pathway
ko00020   

DBGET integrated database retrieval system