Transporter Classification Database

From Wikipedia, the free encyclopedia
Jump to: navigation, search

The Transporter Classification Database (or TCDB) is an International Union of Biochemistry and Molecular Biology (IUBMB)-approved classification system for membrane transport proteins, including ion channels.[1][2][3]



The upper level of classification and a few examples of proteins with known 3D structure:

1. Channels/Pores[edit]

1.A α-type channels[edit]

1.B β-Barrel porins[edit]

1.C Pore-forming toxins (proteins and peptides)[edit]

1.D Non-ribosomally synthesized channels[edit]

1.E Holins[edit]

1.F Vesicle fusion pores[edit]

1.G Viral fusion pores[edit]

1.H Paracellular channels[edit]

1.I Membrane-bound channels[edit]

2. Electrochemical Potential-driven Transporters[edit]

2.A Porters (uniporters, symporters, antiporters)[edit]

2.B Nonribosomally synthesized porters[edit]

2.C Ion-gradient-driven energizers[edit]

3. Primary Active Transporters[edit]

3.A. P-P-bond hydrolysis-driven transporters[edit]

3.B Decarboxylation-driven transporters[edit]

3.C Methyltransfer-driven transporters[edit]

3.D. Oxidoreduction-driven transporters[edit]

3.E. Light absorption-driven transporters[edit]

4. Group Translocators[edit]

4.A Phosphotransfer-driven group translocators[edit]

4.B Nicotinamide ribonucleoside uptake transporters[edit]

4.C Acyl CoA ligase-coupled transporters[edit]

5. Transport Electron Carriers[edit]

5.A Transmembrane 2-electron transfer carriers[edit]

5.B Transmembrane 1-electron transfer carriers[edit]

6. Unused[edit]

Reserved for future expansion

7. Unused[edit]

Reserved for future expansion

8. Accessory Factors Involved in Transport[edit]

8.A Auxiliary transport proteins[edit]

8.B Ribosomally synthesized protein/peptide toxins that target channels and carriers[edit]

8.C Non-ribosomally synthesized toxins that target channels and carriers[edit]

9. Incompletely Characterized Transport Systems[edit]

9.A Recognized transporters of unknown biochemical mechanism[edit]

9.B Putative transport proteins[edit]

9.C Functionally characterized transporters lacking identified sequences[edit]


  1. ^ Saier, Milton H.; Reddy, Vamsee S.; Tamang, Dorjee G.; Västermark, Åke (January 2014). "The Transporter Classification Database". Nucleic Acids Research. 42 (D1): D251–D258. doi:10.1093/nar/gkt1097. Retrieved 1 March 2016. 
  2. ^ Saier, M. H.; Yen, M. R.; Noto, K.; Tamang, D. G.; Elkan, C. (1 January 2009). "The Transporter Classification Database: recent advances". Nucleic Acids Research. 37 (Database): D274–D278. doi:10.1093/nar/gkn862. Retrieved 1 March 2016. 
  3. ^ Saier, M. H.; Tran, C. V.; Barabote, R. D. (1 January 2006). "TCDB: the Transporter Classification Database for membrane transport protein analyses and information". Nucleic Acids Research. 34 (90001): D181–D186. doi:10.1093/nar/gkj001. Retrieved 1 March 2016. 

External links[edit]