PATHWAY: nsy00020 Help
Entry
Name
Citrate cycle (TCA cycle) - Nicotiana sylvestris (wood 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
nsy_M00010 Citrate cycle, first carbon oxidation, oxaloacetate => 2-oxoglutarate [PATH:nsy00020 ]
nsy_M00011 Citrate cycle, second carbon oxidation, 2-oxoglutarate => oxaloacetate [PATH:nsy00020 ]
Other DBs
Organism
Nicotiana sylvestris (wood tobacco) [GN:
nsy ]
Gene
104229441 isocitrate dehydrogenase [NAD] regulatory subunit 1, mitochondrial-like isoform X1 [KO:K00030 ] [EC:1.1.1.41 ]
104218123 dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex 2, mitochondrial-like [KO:K00658 ] [EC:2.3.1.61 ]
104248227 dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex 1, mitochondrial-like [KO:K00658 ] [EC:2.3.1.61 ]
104241425 succinate dehydrogenase [ubiquinone] flavoprotein subunit 1, mitochondrial isoform X1 [KO:K00234 ] [EC:1.3.5.1 ]
104246486 succinate dehydrogenase [ubiquinone] iron-sulfur subunit 2, mitochondrial-like [KO:K00235 ] [EC:1.3.5.1 ]
104249392 pyruvate dehydrogenase E1 component subunit beta-1, mitochondrial-like isoform X1 [KO:K00162 ] [EC:1.2.4.1 ]
104222549 dihydrolipoyllysine-residue acetyltransferase component 4 of pyruvate dehydrogenase complex, chloroplastic-like [KO:K00627 ] [EC:2.3.1.12 ]
104241914 dihydrolipoyllysine-residue acetyltransferase component 2 of pyruvate dehydrogenase complex, mitochondrial-like isoform X1 [KO:K00627 ] [EC:2.3.1.12 ]
104239158 dihydrolipoyllysine-residue acetyltransferase component 5 of pyruvate dehydrogenase complex, chloroplastic [KO:K00627 ] [EC:2.3.1.12 ]
104229812 LOW QUALITY PROTEIN: dihydrolipoyllysine-residue acetyltransferase component 4 of pyruvate dehydrogenase complex, chloroplastic-like [KO:K00627 ] [EC:2.3.1.12 ]
104224582 dihydrolipoyllysine-residue acetyltransferase component 2 of pyruvate dehydrogenase complex, mitochondrial-like [KO:K00627 ] [EC:2.3.1.12 ]
104235087 dihydrolipoyllysine-residue acetyltransferase component 1 of pyruvate dehydrogenase complex, mitochondrial isoform X1 [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
nsy00053 Ascorbate and aldarate metabolism
nsy00250 Alanine, aspartate and glutamate metabolism
nsy00280 Valine, leucine and isoleucine degradation
nsy00630 Glyoxylate and dicarboxylate metabolism
KO pathway
LinkDB
All DBs