Genome Property Definition Page
| Accession | GenProp0033 |
| Name | TCA cycle |
| Type | METAPATH |
| Description | YES 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 Role | TCA cycle |
| Parent Property | GenProp0070: energy metabolism GenProp0611: aerobic respiration |
| Web References | KEGG: Citrate Cycle (TCA cycle) IUBMB: Citric acid cycle |
| Gene Ontology Term | GO:0006099: tricarboxylic acid cycle (biological_process) |
Components
| Step Name | Step Num | Required | Evidence (Method) | Evidence Go Terms |
|---|---|---|---|---|
| citrate synthase | 1 | YES | TIGR01798 (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 hydratase | 2 | YES | TIGR01341 (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 dehydrogenase | 3 | YES | TIGR00175 (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 system | 4 | YES | GenProp0630 (GENPROP): 2-oxoglutarate dehydrogenase system | GO:0006099: tricarboxylic acid cycle |
| succinyl-CoA synthetase, alpha subunit | 5A | YES | TIGR01019 (HMM): succinate-CoA ligase, alpha subunit | GO:0006099: tricarboxylic acid cycle |
| succinyl-CoA synthetase, beta subunit | 5B | YES | TIGR01016 (HMM): succinate-CoA ligase, beta subunit | GO:0006099: tricarboxylic acid cycle |
| succinate dehydrogenase, flavoprotein subunit | 6A | YES | TIGR01816 (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 protein | 6B | YES | TIGR00384 (HMM): succinate dehydrogenase and fumarate reductase iron-sulfur protein | GO:0006099: tricarboxylic acid cycle |
| succinate dehydrogenase, cytochrome b subunit | 6C | YES | TIGR02970 (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 anchor | 6D | NO | TIGR02968 (HMM): succinate dehydrogenase, hydrophobic membrane anchor protein | GO:0006099: tricarboxylic acid cycle |
| fumarate hydratase, class I C-term or class II | 7iC/7ii | YES | TIGR00979 (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 II | 7iN/7ii | YES | TIGR00979 (HMM): fumarate hydratase, class II PF05681 (HMM): fumarate hydratase PMID:2124611 (LITERATURE) | GO:0006099: tricarboxylic acid cycle GO:0006099: tricarboxylic acid cycle |
| malate dehydrogenase | 8 | YES | TIGR01759 (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
| Accession | Name |
|---|---|
| GenProp0070 | energy metabolism |
| GenProp0611 | aerobic respiration |
Child Properties
| Accession | Name |
|---|---|
| GenProp0630 | 2-oxoglutarate dehydrogenase system |
Sibling Properties
| Accession | Name |
|---|---|
| GenProp0011 | methanogenesis |
| GenProp0023 | glyoxylate shunt |
| GenProp0027 | photosynthesis |
| GenProp0120 | pentose phosphate cycle |
| GenProp0131 | electron transport |
| GenProp0243 | ATP synthases |
| GenProp0298 | fermentation |
| GenProp0459 | D-xylose utilization (conversion to D-xylulose-5-phosphate) |
| GenProp0468 | Entner-Doudoroff pathway |
| GenProp0473 | arsenite oxidase |
| GenProp0611 | aerobic respiration |
| GenProp0636 | respiratory nitrate reductase |
| GenProp0637 | anaerobic dimethyl sulfoxide reductase |
| GenProp0638 | trimethylamine N-oxide reductase system |
| GenProp0682 | formate-dependent nitrite reductase, seven-gene type |
| GenProp0683 | cytochrome c nitrite reductase NrfHA |
| GenProp0691 | glycolysis |
| GenProp0695 | cytochrome b558/566 |
| GenProp0723 | hydrogenase, nickel and F420-dependent |
| GenProp0737 | anaerobic glycerol-3-phosphate dehydrogenase complex |
| GenProp0755 | pyruvate conversion to propionate, anaerobic, FAD/NAD-regenerating |
| GenProp0756 | fumarate reductase complex |
| GenProp0764 | DMSO reductase family type II enzyme |
| GenProp0841 | 2-oxoacid:ferredoxin oxidoreductase |
| GenProp0856 | bacterio-opsin system |
| GenProp0914 | hydrogenase, [FeFe]-dependent |
| GenProp0915 | hydrogenase, mono-iron type |
| GenProp1089 | B12-dependent trimeric diol/glycerol dehydratase |
| GenProp1101 | quinoprotein cytochrome relay system |
| GenProp0128 | F1/F0 ATPase |
| GenProp0612 | aerobic electron transfer (transport) chain, ETC |