PATHWAY: nta00020 Help
Entry
Name
Citrate cycle (TCA cycle) - Nicotiana tabacum (common tobacco)
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
nta_M00010 Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:nta00020 ]
nta_M00011 Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:nta00020 ]
Other DBs
Organism
Nicotiana tabacum (common tobacco) [GN:
nta ]
Gene
107800735 dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex 1, mitochondrial-like [KO:K00658 ] [EC:2.3.1.61 ]
107828007 dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex 1, mitochondrial-like [KO:K00658 ] [EC:2.3.1.61 ]
107819849 dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex 1, mitochondrial-like [KO:K00658 ] [EC:2.3.1.61 ]
107795955 succinate dehydrogenase [ubiquinone] flavoprotein subunit 1, mitochondrial-like [KO:K00234 ] [EC:1.3.5.1 ]
107809996 succinate dehydrogenase [ubiquinone] iron-sulfur subunit 3, mitochondrial-like [KO:K00235 ] [EC:1.3.5.1 ]
107802674 succinate dehydrogenase [ubiquinone] iron-sulfur subunit 2, mitochondrial-like [KO:K00235 ] [EC:1.3.5.1 ]
107782822 succinate dehydrogenase [ubiquinone] iron-sulfur subunit 3, mitochondrial-like [KO:K00235 ] [EC:1.3.5.1 ]
107801918 succinate dehydrogenase [ubiquinone] iron-sulfur subunit 2, mitochondrial-like [KO:K00235 ] [EC:1.3.5.1 ]
107813986 dihydrolipoyllysine-residue acetyltransferase component 1 of pyruvate dehydrogenase complex, mitochondrial-like [KO:K00627 ] [EC:2.3.1.12 ]
107764742 dihydrolipoyllysine-residue acetyltransferase component 4 of pyruvate dehydrogenase complex, chloroplastic-like [KO:K00627 ] [EC:2.3.1.12 ]
107817385 dihydrolipoyllysine-residue acetyltransferase component 5 of pyruvate dehydrogenase complex, chloroplastic-like [KO:K00627 ] [EC:2.3.1.12 ]
107802375 dihydrolipoyllysine-residue acetyltransferase component 4 of pyruvate dehydrogenase complex, chloroplastic-like [KO:K00627 ] [EC:2.3.1.12 ]
107827422 dihydrolipoyllysine-residue acetyltransferase component 2 of pyruvate dehydrogenase complex, mitochondrial-like [KO:K00627 ] [EC:2.3.1.12 ]
107817052 dihydrolipoyllysine-residue acetyltransferase component 1 of pyruvate dehydrogenase complex, mitochondrial-like [KO:K00627 ] [EC:2.3.1.12 ]
107772318 dihydrolipoyllysine-residue acetyltransferase component 2 of pyruvate dehydrogenase complex, mitochondrial-like [KO:K00627 ] [EC:2.3.1.12 ]
107797489 dihydrolipoyllysine-residue acetyltransferase component 5 of pyruvate dehydrogenase complex, chloroplastic-like [KO:K00627 ] [EC:2.3.1.12 ]
107768212 dihydrolipoyllysine-residue acetyltransferase component 2 of pyruvate dehydrogenase complex, mitochondrial-like [KO:K00627 ] [EC:2.3.1.12 ]
107788125 dihydrolipoyllysine-residue acetyltransferase component 2 of pyruvate dehydrogenase complex, mitochondrial-like [KO:K00627 ] [EC:2.3.1.12 ]
107809523 dihydrolipoyllysine-residue acetyltransferase component 4 of pyruvate dehydrogenase complex, chloroplastic-like [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
nta00053 Ascorbate and aldarate metabolism
nta00250 Alanine, aspartate and glutamate metabolism
nta00280 Valine, leucine and isoleucine degradation
nta00630 Glyoxylate and dicarboxylate metabolism
KO pathway
LinkDB
All DBs