KEGG   PATHWAY: bta00020
Entry
bta00020                    Pathway                                
Name
Citrate cycle (TCA cycle) - Bos taurus (cow)
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
bta00020  Citrate cycle (TCA cycle)
bta00020

Module
bta_M00003  Gluconeogenesis, oxaloacetate => fructose-6P [PATH:bta00020]
bta_M00009  Citrate cycle (TCA cycle, Krebs cycle) [PATH:bta00020]
bta_M00010  Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:bta00020]
bta_M00011  Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:bta00020]
bta_M00307  Pyruvate oxidation, pyruvate => acetyl-CoA [PATH:bta00020]
Other DBs
GO: 0006099
Organism
Bos taurus (cow) [GN:bta]
Gene
280682  CS; citrate synthase, mitochondrial precursor [KO:K01647] [EC:2.3.3.1]
511135  ACLY; ATP-citrate synthase [KO:K01648] [EC:2.3.3.8]
280976  ACO2; aconitate hydratase, mitochondrial precursor [KO:K01681] [EC:4.2.1.3]
512995  ACO1; cytoplasmic aconitate hydratase [KO:K01681] [EC:4.2.1.3]
327669  IDH2; isocitrate dehydrogenase [NADP], mitochondrial precursor [KO:K00031] [EC:1.1.1.42]
281235  IDH1; isocitrate dehydrogenase [NADP] cytoplasmic [KO:K00031] [EC:1.1.1.42]
282446  IDH3A; isocitrate dehydrogenase [NAD] subunit alpha, mitochondrial precursor [KO:K00030] [EC:1.1.1.41]
613338  IDH3B; isocitrate dehydrogenase [NAD] subunit beta, mitochondrial isoform 2 precursor [KO:K00030] [EC:1.1.1.41]
614145  IDH3G; isocitrate dehydrogenase [NAD] subunit gamma, mitochondrial precursor [KO:K00030] [EC:1.1.1.41]
531398  OGDHL; 2-oxoglutarate dehydrogenase-like, mitochondrial [KO:K00164] [EC:1.2.4.2]
534599  OGDH; 2-oxoglutarate dehydrogenase complex component E1 precursor [KO:K00164] [EC:1.2.4.2]
132342072  LOW QUALITY PROTEIN: 2-oxoglutarate dehydrogenase complex component E1-like [KO:K00164] [EC:1.2.4.2]
506888  DLST; dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex, mitochondrial [KO:K00658] [EC:2.3.1.61]
533910  DLD; dihydrolipoyl dehydrogenase, mitochondrial [KO:K00382] [EC:1.8.1.4]
509983  SUCLG1; succinate--CoA ligase [ADP/GDP-forming] subunit alpha, mitochondrial precursor [KO:K01899] [EC:6.2.1.4 6.2.1.5]
537713  SUCLG2; succinate--CoA ligase [GDP-forming] subunit beta, mitochondrial precursor [KO:K01900] [EC:6.2.1.4 6.2.1.5]
511090  SUCLA2; succinate--CoA ligase [ADP-forming] subunit beta, mitochondrial [KO:K01900] [EC:6.2.1.4 6.2.1.5]
281480  SDHA; succinate dehydrogenase [ubiquinone] flavoprotein subunit, mitochondrial precursor [KO:K00234] [EC:1.3.5.1]
286840  SDHB; succinate dehydrogenase [ubiquinone] iron-sulfur subunit, mitochondrial precursor [KO:K00235] [EC:1.3.5.1]
327696  SDHC; succinate dehydrogenase cytochrome b560 subunit, mitochondrial precursor [KO:K00236]
281481  SDHD; succinate dehydrogenase [ubiquinone] cytochrome b small subunit, mitochondrial precursor [KO:K00237]
520260  FH; fumarate hydratase, mitochondrial [KO:K01679] [EC:4.2.1.2]
535182  MDH1; malate dehydrogenase, cytoplasmic isoform MDH1 [KO:K00025] [EC:1.1.1.37]
281306  MDH2; malate dehydrogenase, mitochondrial [KO:K00026] [EC:1.1.1.37]
338471  PC; pyruvate carboxylase, mitochondrial precursor [KO:K01958] [EC:6.4.1.1]
282855  PCK1; phosphoenolpyruvate carboxykinase, cytosolic [GTP] [KO:K01596] [EC:4.1.1.32]
282856  PCK2; phosphoenolpyruvate carboxykinase [GTP], mitochondrial [KO:K01596] [EC:4.1.1.32]
407109  PDHA1; pyruvate dehydrogenase E1 component subunit alpha, somatic form, mitochondrial precursor [KO:K00161] [EC:1.2.4.1]
768012  PDHA2; pyruvate dehydrogenase E1 component subunit alpha, testis-specific form, mitochondrial [KO:K00161] [EC:1.2.4.1]
613610  PDHB; pyruvate dehydrogenase E1 component subunit beta, mitochondrial precursor [KO:K00162] [EC:1.2.4.1]
512723  DLAT; 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
bta00010  Glycolysis / Gluconeogenesis
bta00053  Ascorbate and aldarate metabolism
bta00061  Fatty acid biosynthesis
bta00062  Fatty acid elongation
bta00071  Fatty acid degradation
bta00190  Oxidative phosphorylation
bta00220  Arginine biosynthesis
bta00250  Alanine, aspartate and glutamate metabolism
bta00280  Valine, leucine and isoleucine degradation
bta00350  Tyrosine metabolism
bta00470  D-Amino acid metabolism
bta00630  Glyoxylate and dicarboxylate metabolism
KO pathway
ko00020   
LinkDB

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