2.A.25 The Alanine or Glycine:Cation Symporter (AGCS) Family

Members of the AGCS family transport alanine and/or glycine in symport with Na+ and or H+. The proteins are of 445-542 amino acyl residues in length and possess 8-12 putative transmembrane α-helical spanners. They may possess 11 TMSs as seems to be true for DagA and AgcS, although Acp has only 8 (truncated?). They are found in bacteria and archaea. Only three members of the family have been functionally characterized. These proteins show limited sequence similarity in the APC family (TC# 2.A.3), and homology has been established.

The generalized transport reaction catalyzed by the AGCS family is:

alanine or glycine (out) + Na+ or H+ (out) → alanine or glycine (in) + Na+ or H+ (in).

This family belongs to the APC Superfamily.



Bualuang A., Kageyama H., Tanaka Y., Incharoensakdi A. and Takabe T. (201). Functional characterization of a member of alanine or glycine: cation symporter family in halotolerant cyanobacterium Aphanothece halophytica. Biosci Biotechnol Biochem. 79(2):230-5.

Kamata, H., S. Akiyama, H. Morosawa, T. Ohta, T. Hamamoto, T. Kambe, Y. Kagawa, and H. Hirata. (1992). Primary structure of the alanine carrier protein of thermophilic bacterium PS3. J. Biol. Chem. 267: 21650-21655.

Kanamori, M., H. Kamata, H. Yagisawa, and H. Hirata. (1999). Overexpression of the alanine carrier protein gene from thermophilic bacterium PS3 in Escherichia coli. J Biochem 125: 454-459.

Moore, B.C. and J.A. Leigh. (2005). Markerless mutagenesis in Methanococcus maripaludis demonstrates roles for alanine dehydrogenase, alanine racemase, and alanine permease. J. Bacteriol. 187: 972-979.

Reizer, J., A. Reizer and M.H. Saier, Jr. (1994). A functional superfamily of sodium/solute symporters. Biochim. Biophys. Acta 1197: 133-166.

Rodionov, D.A., P. Hebbeln, A. Eudes, J. ter Beek, I.A. Rodionova, G.B. Erkens, D.J. Slotboom, M.S. Gelfand, A.L. Osterman, A.D. Hanson, and T. Eitinger. (2009). A novel class of modular transporters for vitamins in prokaryotes. J. Bacteriol. 191: 42-51.

Rodionov, D.A., P.S. Novichkov, E.D. Stavrovskaya, I.A. Rodionova, X. Li, M.D. Kazanov, D.A. Ravcheev, A.V. Gerasimova, A.E. Kazakov, G.Y. Kovaleva, E.A. Permina, O.N. Laikova, R. Overbeek, M.F. Romine, J.K. Fredrickson, A.P. Arkin, I. Dubchak, A.L. Osterman, and M.S. Gelfand. (2011). Comparative genomic reconstruction of transcriptional networks controlling central metabolism in the Shewanella genus. BMC Genomics 12Suppl1: S3.

Yoshida, K., H. Yamaguchi, M. Kinehara, Y.H. Ohki, Y. Nakaura, and Y. Fujita. (2003). Identification of additional TnrA-regulated genes of Bacillus subtilis associated with a TnrA box. Mol. Microbiol. 49: 157-165.


TC#NameOrganismal TypeExample
2.A.25.1.1Alanine (or glycine):Na+ symporter Bacteria DagA of Alteromonas haloplanktis

Putative Ala/Gly transporter of 476 aas and 11 TMSs, YaaJ

YaaJ of E. coli


Alanine:Na+ (or H+) symporter (Kamata et al. 1992; Kanamori et al. 1999).  The sequence as reported appears to lack the first 45 aas and the first two tMSs, probably because of incorrect initiation codon selection.


Acp of thermophilic bacterium PS-3

2.A.25.1.3Alanine:Na+ symporter, AgcS (Moore and Leigh, 2005)ArchaeaAgcS of Methanococcus maripaludis (CAF31067)

The putative glycine porter, GlyP. Regulated by Glycine riboswitch (Rodionov et al. 2011)

Proteobacteria, Firmicutes

GlyP of Shewanella oneidensis (Q8EII1)


Amino-acid carrier protein, AlsT.  Negatively regulated by TnrA (Yoshida et al. 2003).


AlsT of Bacillus subtilis




Bifunctional protein of Leptospira biflexa


Putative alanine/glycine transporter of 443 aas and 11 TMSs.


PP of Anaplasma phagocytophilum


Putative alanine/glycine transporter of 447 aas and 11 TMSs.


Putative transporter of Clostridium novyi


Probable Glycine/alanine/asparagine/glutamine uptake porter, AgcS (Bualuang et al. 2014).


AgcS of Pseudomonas aeruginosa


TC#NameOrganismal TypeExample