PROSITE documentation PDOC00937
Ammonium transporters signature


A number of proteins involved in the transport of ammonium ions across a membrane as well as some yet uncharacterized proteins have been shown [1,2] to be evolutionary related. These proteins are:

  • Yeast ammonium transporters MEP1, MEP2 and MEP3.
  • Arabidopsis thaliana high affinity ammonium transporter (gene AMT1).
  • Corynebacterium glutamicum ammonium and methylammonium transport system.
  • Escherichia coli putative ammonium transporter amtB.
  • Bacillus subtilis nrgA.
  • Mycobacterium tuberculosis hypothetical protein MtCY338.09c.
  • Synechocystis strain PCC 6803 hypothetical proteins sll0108, sll0537 and sll1017.
  • Methanococcus jannaschii hypothetical proteins MJ0058 and MJ1343.
  • Caenorhabditis elegans hypothetical proteins C05E11.4, F49E11.3 and M195.3.

As expected by their transport function, these proteins are highly hydrophobic and seem to contain from 10 to 12 transmembrane domains. The best conserved region seems to be located in the fifth (or sixth) transmembrane region and is used as a signature pattern.


These proteins belongs to family TC 2.49 in the classification of transporters [3].

Last update:

December 2004 / Pattern and text revised.


Technical section

PROSITE method (with tools and information) covered by this documentation:

AMMONIUM_TRANSP, PS01219; Ammonium transporters signature  (PATTERN)


1AuthorsNinnemann O. Jauniaux J.-C. Frommer W.B.
TitleIdentification of a high affinity NH4+ transporter from plants.
SourceEMBO J. 13:3464-3471(1994).
PubMed ID8062823

2AuthorsSiewe R.M. Weil B. Burkovski A. Eikmanns B.J. Eikmanns M. Kramer R.
TitleFunctional and genetic characterization of the (methyl)ammonium uptake carrier of Corynebacterium glutamicum.
SourceJ. Biol. Chem. 271:5398-5403(1996).
PubMed ID8621394

3AuthorsSaier M.H. Jr.
SourceAdv. Microbiol. Physiol. 40:81-136(1998).

PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see prosite_license.html.


View entry in original PROSITE document format
View entry in raw text format (no links)