GenProp0033 - TCA cycle

Type: METAPATH

Author: Haft DH

Description

The TCA cycle (also known as the Krebs cycle, citrate acid 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 CO2. 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 state PARTIAL indicates the pathway does not form a full cycle but may contain several consecutive steps. The direction of flux through this arc is not specified when the PARTIAL state is set, and so it may be in the reductive (reverse) direction. The full reverse TCA cycle, an alternative to the Calvin cycle for carbon dioxide fixation, is covered by a separate property.

References

    None

Database Links

  • Citric acid cycle: IUBMB
  • Citrate Cycle (TCA cycle): KEGG

Steps

StepEvidenceGo Terms
1. Citrate synthaseIPR010953 - TIGR01798GO:0006099
IPR011278 - TIGR01800GO:0006099
IPR010109 - TIGR01793GO:0006099
2. Aconitate hydrataseIPR006249 - TIGR01341GO:0006099
IPR004406 - TIGR00117GO:0006099
IPR006248 - TIGR01340GO:0006099
3. Isocitrate dehydrogenaseIPR004434 - TIGR00175GO:0006099
IPR004790 - TIGR00127GO:0006099
IPR004436 - TIGR00178GO:0006099
IPR004439 - TIGR00183GO:0006099
IPR014273 - TIGR02924GO:0006099
5. Succinyl-CoA synthetase, alpha subunitIPR005810 - TIGR01019GO:0006099
6. Succinyl-CoA synthetase, beta subunitIPR005809 - TIGR01016GO:0006099
7. Succinate dehydrogenase, flavoprotein subunitIPR011281 - TIGR01816GO:0006099
IPR011280 - TIGR01811GO:0006099
8. Succinate dehydrogenase, iron-sulfur proteinIPR004489 - TIGR00384GO:0006099
9. Succinate dehydrogenase, cytochrome b subunitIPR014314 - TIGR02970GO:0006099
IPR011138 - TIGR02046None
10. Succinate dehydrogenase, hydrophobic membrane anchor
Optional
IPR014312 - TIGR02968GO:0006099
11. Fumarate hydratase, class I C-term or class IIIPR005677 - TIGR00979GO:0006099
IPR004647 - GO:0006099
12. Fumarate hydratase, class I N-term or class IIIPR005677 - TIGR00979GO:0006099
IPR004646 - None
13. Malate dehydrogenaseIPR010945 - TIGR01759None
IPR011274 - TIGR01758GO:0006099
IPR011275 - TIGR01763GO:0006099
IPR010097 - TIGR01772GO:0006099
IPR006231 - TIGR01320GO:0006099
Threshold: 5