PATHWAY: egu00020 Help
Entry
Name
Citrate cycle (TCA cycle) - Elaeis guineensis (African oil palm)
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
egu_M00010 Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:egu00020 ]
egu_M00011 Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:egu00020 ]
Other DBs
Organism
Elaeis guineensis (African oil palm) [GN:
egu ]
Gene
105051043 dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex 2, mitochondrial [KO:K00658 ] [EC:2.3.1.61 ]
105061406 dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex 1, mitochondrial isoform X1 [KO:K00658 ] [EC:2.3.1.61 ]
105034968 dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex 1, mitochondrial-like [KO:K00658 ] [EC:2.3.1.61 ]
105060729 succinate dehydrogenase [ubiquinone] flavoprotein subunit, mitochondrial isoform X1 [KO:K00234 ] [EC:1.3.5.1 ]
105051324 succinate dehydrogenase [ubiquinone] iron-sulfur subunit 1, mitochondrial-like [KO:K00235 ] [EC:1.3.5.1 ]
105046915 succinate dehydrogenase subunit 3-2, mitochondrial-like [KO:K00236 ]
105051662 succinate dehydrogenase subunit 3-2, mitochondrial-like [KO:K00236 ]
105045533 succinate dehydrogenase subunit 4, mitochondrial-like [KO:K25801 ]
105050071 pyruvate dehydrogenase E1 component subunit alpha-1, mitochondrial-like isoform X1 [KO:K00161 ] [EC:1.2.4.1 ]
105059287 LOW QUALITY PROTEIN: pyruvate dehydrogenase E1 component subunit alpha-3, chloroplastic [KO:K00161 ] [EC:1.2.4.1 ]
105050691 pyruvate dehydrogenase E1 component subunit alpha-1, mitochondrial isoform X1 [KO:K00161 ] [EC:1.2.4.1 ]
105035588 dihydrolipoyllysine-residue acetyltransferase component 4 of pyruvate dehydrogenase complex, chloroplastic [KO:K00627 ] [EC:2.3.1.12 ]
105038468 dihydrolipoyllysine-residue acetyltransferase component 5 of pyruvate dehydrogenase complex, chloroplastic-like [KO:K00627 ] [EC:2.3.1.12 ]
105046063 LOW QUALITY PROTEIN: dihydrolipoyllysine-residue acetyltransferase component 1 of pyruvate dehydrogenase complex, mitochondrial-like [KO:K00627 ] [EC:2.3.1.12 ]
105059487 dihydrolipoyllysine-residue acetyltransferase component 2 of pyruvate dehydrogenase complex, mitochondrial-like [KO:K00627 ] [EC:2.3.1.12 ]
105054728 dihydrolipoyllysine-residue acetyltransferase component 2 of pyruvate dehydrogenase complex, mitochondrial [KO:K00627 ] [EC:2.3.1.12 ]
105051780 LOW QUALITY PROTEIN: dihydrolipoyllysine-residue acetyltransferase component 5 of pyruvate dehydrogenase complex, chloroplastic [KO:K00627 ] [EC:2.3.1.12 ]
105052355 dihydrolipoyllysine-residue acetyltransferase component 1 of pyruvate dehydrogenase complex, mitochondrial [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
egu00053 Ascorbate and aldarate metabolism
egu00250 Alanine, aspartate and glutamate metabolism
egu00280 Valine, leucine and isoleucine degradation
egu00630 Glyoxylate and dicarboxylate metabolism
KO pathway
LinkDB
All DBs