PATHWAY: bta00020 Help
Entry
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
BRITE hierarchy
Pathway map
Ortholog table
Module
bta_M00010 Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:bta00020 ]
bta_M00011 Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:bta00020 ]
Other DBs
Organism
Bos taurus (cow) [GN:
bta ]
Gene
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 ]
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 ]
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 ]
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
C05125 2-(alpha-Hydroxyethyl)thiamine diphosphate
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
bta00053 Ascorbate and aldarate metabolism
bta00250 Alanine, aspartate and glutamate metabolism
bta00280 Valine, leucine and isoleucine degradation
bta00630 Glyoxylate and dicarboxylate metabolism
KO pathway
LinkDB
All DBs