Citrate cycle (TCA cycle) Gene Set

Dataset KEGG Pathways 2026
Category structural or functional annotations
Type pathway
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]. (Kyoto Encyclopedia of Genes and Genomes, hsa00020)
External Link https://www.kegg.jp/entry/hsa00020
Similar Terms
Downloads & Tools

Genes

30 proteins participating in the Citrate cycle (TCA cycle) pathway from the KEGG Pathways 2026 dataset.

Symbol Name
ACLY ATP citrate lyase
ACO1 aconitase 1, soluble
ACO2 aconitase 2, mitochondrial
CS citrate synthase
DLAT dihydrolipoamide S-acetyltransferase
DLST dihydrolipoamide S-succinyltransferase (E2 component of 2-oxo-glutarate complex)
IDH1 isocitrate dehydrogenase 1 (NADP+), soluble
IDH2 isocitrate dehydrogenase 2 (NADP+), mitochondrial
IDH3A isocitrate dehydrogenase 3 (NAD+) alpha
IDH3B isocitrate dehydrogenase 3 (NAD+) beta
IDH3G isocitrate dehydrogenase 3 (NAD+) gamma
LDHD lactate dehydrogenase D
LDLR low density lipoprotein receptor
MDH1 malate dehydrogenase 1, NAD (soluble)
MDH2 malate dehydrogenase 2, NAD (mitochondrial)
OGDH oxoglutarate (alpha-ketoglutarate) dehydrogenase (lipoamide)
OGDHL oxoglutarate dehydrogenase-like
PCK1 phosphoenolpyruvate carboxykinase 1 (soluble)
PCK2 phosphoenolpyruvate carboxykinase 2 (mitochondrial)
PDHA1 pyruvate dehydrogenase (lipoamide) alpha 1
PDHA2 pyruvate dehydrogenase (lipoamide) alpha 2
PDHB pyruvate dehydrogenase (lipoamide) beta
PROC protein C (inactivator of coagulation factors Va and VIIIa)
SDHA succinate dehydrogenase complex, subunit A, flavoprotein (Fp)
SDHB succinate dehydrogenase complex, subunit B, iron sulfur (Ip)
SDHC succinate dehydrogenase complex, subunit C, integral membrane protein, 15kDa
SDHD succinate dehydrogenase complex, subunit D, integral membrane protein
SUCLA2 succinate-CoA ligase, ADP-forming, beta subunit
SUCLG1 succinate-CoA ligase, alpha subunit
SUCLG2 succinate-CoA ligase, GDP-forming, beta subunit