Genome Property Definition Page

AccessionGenProp0033
NameTCA cycle
TypeMETAPATH
DescriptionYES NO PARTIAL The TCA cycle, also called the Krebs cycle, citrate cycle, and tricarboxylic acid cycle, is performed in eukaryotic mitochondria and in many prokaryotes. This property refers to the forward direction: from oxaloacetate and acetate to citrate, to isocitrate, to 2-oxoglutarate, to succinate, to fumarate, to malate, to oxaloacetate, with the release of two molecules of C02. It runs only under aerobic conditions. The state YES means the cycle is complete. A complete TCA cycle may correlate with use of TCA intermediates as biosynthetic precursors and with anaplerotic (TCA cycle intermediate-replenishing) reactions such as the glyoxylate shunt. The PARTIAL state indicates the pathway does not form a cycle but may contain several consecutive steps. The direction of flux through this arc is not specified when the state is set and may be in the reductive (reverse) direction. The reverse TCA cycle, an alternative to the Calvin cycle for carbon dioxide fixation, is covered by a separate property.
JCVI RoleTCA cycle
Parent PropertyGenProp0070: energy metabolism
GenProp0611: aerobic respiration
Web ReferencesKEGG: Citrate Cycle (TCA cycle)
IUBMB: Citric acid cycle
Gene Ontology TermGO:0006099: tricarboxylic acid cycle (biological_process)

Components
Step NameStep NumRequiredEvidence (Method)Evidence Go Terms
citrate synthase1YESTIGR01798 (HMM): citrate (Si)-synthase
TIGR01800 (HMM): 2-methylcitrate synthase/citrate synthase II
TIGR01793 (HMM): citrate (Si)-synthase, eukaryotic
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
aconitate hydratase2YESTIGR01341 (HMM): aconitate hydratase 1
TIGR00117 (HMM): aconitate hydratase 2
TIGR01340 (HMM): aconitate hydratase, mitochondrial
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
isocitrate dehydrogenase3YESTIGR00175 (HMM): isocitrate dehydrogenase, NAD-dependent
TIGR00127 (HMM): isocitrate dehydrogenase, NADP-dependent
TIGR00178 (HMM): isocitrate dehydrogenase, NADP-dependent
TIGR00183 (HMM): isocitrate dehydrogenase, NADP-dependent
TIGR02924 (HMM): isocitrate dehydrogenase
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
2-oxoglutarate dehydrogenase system4YESGenProp0630 (GENPROP): 2-oxoglutarate dehydrogenase system
GO:0006099: tricarboxylic acid cycle
succinyl-CoA synthetase, alpha subunit5AYESTIGR01019 (HMM): succinate-CoA ligase, alpha subunitGO:0006099: tricarboxylic acid cycle
succinyl-CoA synthetase, beta subunit5BYESTIGR01016 (HMM): succinate-CoA ligase, beta subunitGO:0006099: tricarboxylic acid cycle
succinate dehydrogenase, flavoprotein subunit6AYESTIGR01816 (HMM): succinate dehydrogenase, flavoprotein subunit
TIGR01811 (HMM): succinate dehydrogenase or fumarate reductase, flavoprotein subunit
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
succinate dehydrogenase, iron-sulfur protein6BYESTIGR00384 (HMM): succinate dehydrogenase and fumarate reductase iron-sulfur proteinGO:0006099: tricarboxylic acid cycle
succinate dehydrogenase, cytochrome b subunit6CYESTIGR02970 (HMM): succinate dehydrogenase, cytochrome b556 subunit
TIGR02046 (HMM): succinate dehydrogenase (or fumarate reductase) cytochrome b subunit, b558 family
GO:0006099: tricarboxylic acid cycle
succinate dehydrogenase, hydrophobic membrane anchor6DNOTIGR02968 (HMM): succinate dehydrogenase, hydrophobic membrane anchor proteinGO:0006099: tricarboxylic acid cycle
fumarate hydratase, class I C-term or class II7iC/7iiYESTIGR00979 (HMM): fumarate hydratase, class II
PF05683 (HMM): fumarate hydratase I, C-terminal region or beta subunit
PMID:2124611 (LITERATURE)
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
fumarate hydratase, class I N-term or class II7iN/7iiYESTIGR00979 (HMM): fumarate hydratase, class II
PF05681 (HMM): fumarate hydratase
PMID:2124611 (LITERATURE)
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
malate dehydrogenase8YESTIGR01759 (HMM): malate dehydrogenase
TIGR01758 (HMM): malate dehydrogenase, NAD-dependent
TIGR01763 (HMM): malate dehydrogenase, NAD-dependent
TIGR01772 (HMM): malate dehydrogenase, NAD-dependent
TIGR01320 (HMM): malate dehydrogenase (acceptor)
PMID:3109450 (LITERATURE)
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle
GO:0006099: tricarboxylic acid cycle

Parent Properties
AccessionName
GenProp0070energy metabolism
GenProp0611aerobic respiration

Child Properties
AccessionName
GenProp06302-oxoglutarate dehydrogenase system

Sibling Properties
AccessionName
GenProp0011methanogenesis
GenProp0023glyoxylate shunt
GenProp0027photosynthesis
GenProp0120pentose phosphate cycle
GenProp0131electron transport
GenProp0243ATP synthases
GenProp0298fermentation
GenProp0459D-xylose utilization (conversion to D-xylulose-5-phosphate)
GenProp0468Entner-Doudoroff pathway
GenProp0473arsenite oxidase
GenProp0611aerobic respiration
GenProp0636respiratory nitrate reductase
GenProp0637anaerobic dimethyl sulfoxide reductase
GenProp0638trimethylamine N-oxide reductase system
GenProp0682formate-dependent nitrite reductase, seven-gene type
GenProp0683cytochrome c nitrite reductase NrfHA
GenProp0691glycolysis
GenProp0695cytochrome b558/566
GenProp0723hydrogenase, nickel and F420-dependent
GenProp0737anaerobic glycerol-3-phosphate dehydrogenase complex
GenProp0755pyruvate conversion to propionate, anaerobic, FAD/NAD-regenerating
GenProp0756fumarate reductase complex
GenProp0764DMSO reductase family type II enzyme
GenProp08412-oxoacid:ferredoxin oxidoreductase
GenProp0856bacterio-opsin system
GenProp0914hydrogenase, [FeFe]-dependent
GenProp0915hydrogenase, mono-iron type
GenProp1089B12-dependent trimeric diol/glycerol dehydratase
GenProp0128F1/F0 ATPase
GenProp0612aerobic electron transfer (transport) chain, ETC