Branched chain amino acid–cation symporter

The branched chain amino acid:cation symporter (LIVCS) family (TC# 2.A.26) is a member of the APC superfamily. Characterized members of this family transport all three of the branched chain aliphatic amino acids (leucine (L), isoleucine (I) and valine (V)). These proteins are found in Gram-negative and Gram-positive bacteria and function by a Na⁺ or H⁺ symport mechanism. They possess about 440 amino acyl residues and display 12 putative transmembrane helical spanners. As of early 2016, no crystal structures for members of the LIVCS family are available on RCSB.

Transport reaction

The generalized transport reaction is:

[L, I or V] (out) + [Na⁺ or H⁺] (out) → [L, I or V] (in) + [Na⁺ or H⁺] (in).

Proteins

As of early 2016, there are 10 known proteins in the LIVCS family. These can be found in the Transporter Classification Database.

Further reading

• Braun, Peter R.; Al-Younes, Hesham; Gussmann, Joscha; Klein, Jeannette; Schneider, Erwin; Meyer, Thomas F. (2008-03-01). "Competitive inhibition of amino acid uptake suppresses chlamydial growth: involvement of the chlamydial amino acid transporter BrnQ". Journal of Bacteriology 190 (5): 1822–1830. doi:10.1128/JB.01240-07. ISSN 1098-5530. PMC 2258683. PMID 18024516.
• Böhmer, Christine; Rauhut, Oliver W. M.; Wörheide, Gert (2015-07-07). "Correlation between Hox code and vertebral morphology in archosaurs". Proceedings of the Royal Society B: Biological Sciences 282 (1810). doi:10.1098/rspb.2015.0077. ISSN 0962-8452. PMC 4590465. PMID 26085583.
• Trip, Hein; Mulder, Niels L.; Lolkema, Juke S. (2013-01-01). "Cloning, expression, and functional characterization of secondary amino acid transporters of Lactococcus lactis". Journal of Bacteriology 195 (2): 340–350. doi:10.1128/JB.01948-12. ISSN 1098-5530. PMC 3553839. PMID 23144255.
• Reizer, J; Reizer, A; Saier, MH Jr. (June 29, 1994). "A functional superfamily of sodium/solute symporters.". 1197(2): (2): 133–66. PMID 8031825.