CPA superfamily explained

The cation:proton antiporter (CPA) superfamily is a superfamily of transport proteins named after one of its constituent members, the (CPA2).

CPA1 was considered a member of the superfamily until 2010, when it was discovered to in fact be a member of the VIC superfamily.^{[1] [2] [3]} As of April 2016, the CPA superfamily consists of four members:

• family^[4]
• family^[5]
• Putative sulfate exporter family^[6]
• Sodium-transporting carboxylic acid decarboxylase family^[7]

Structural variation exists between families. For example, members of the CPA2 family are between 300 and 900 amino acyl residues (aas) in length and exhibit 10 to 14 transmembrane segments (TMSs), while members of the MSS family are shorter than 300 aas and exhibit 4 to 7 TMSs.

See also

• Transporter Classification Database

Further reading

• Chang . Abraham B. . Lin . Ron . Keith Studley . W. . Tran . Can V. . Saier . Milton H. . 2004 . Phylogeny as a guide to structure and function of membrane transport proteins . Molecular Membrane Biology . 21 . 3. 171–181 . 10.1080/09687680410001720830 . 15204625 .

Notes and References

1. Chen. Jonathan S.. Reddy. Vamsee. Chen. Joshua H.. Shlykov. Maksim A.. Zheng. Wei Hao. Cho. Jaehoon. Yen. Ming Ren. Saier. Milton H. Jr.. Phylogenetic Characterization of Transport Protein Superfamilies: Superiority of SuperfamilyTree Programs over Those Based on Multiple Alignments. Journal of Molecular Microbiology and Biotechnology. 21. 3–4. 83–96. 10.1159/000334611. 3290041. 22286036. 2011.
2. Koishi. Ryuta. Xu. Haoxing. Ren. Dejian. Navarro. Betsy. Spiller. Benjamin W.. Shi. Qing. Clapham. David E.. 2004-03-05. A superfamily of voltage-gated sodium channels in bacteria. The Journal of Biological Chemistry. 279. 10. 9532–9538. 10.1074/jbc.M313100200. 0021-9258. 14665618. free.
3. Web site: 1.A.1 The Voltage-gated Ion Channel (VIC) Superfamily. Transporter Classification Database. 2016-04-05.
4. Web site: 2.A.37 The Monovalent Cation:Proton Antiporter-2 (CPA2) Family. Transporter Classification Database.
5. Web site: 2.A.70 The Malonate:Na+ Symporter (MSS) Family. Transporter Classification Database .
6. Web site: 2.A.98 The Putative Sulfate Exporter (PSE) Family . Transporter Classification Database .
7. Web site: 3.B.1 The Na+-transporting Carboxylic Acid Decarboxylase (NaT-DC) Family. Transporter Classification Database .