To improve security and privacy, we are moving our web pages and services from HTTP to HTTPS.
To give users of web services time to transition to HTTPS, we will support separate HTTP and HTTPS services until the end of 2017.
From January 2018 most HTTP traffic will be automatically redirected to HTTPS. [more...]
View this page in https
PROSITE documentation PDOC00680 [for PROSITE entry PS00872]

Sodium:galactoside symporter family signature





Description

It has been shown [1] that integral membrane proteins that mediate the intake of a wide variety of molecules with the concomitant uptake of sodium ions (sodium symporters) can be grouped, on the basis of sequence and functional similarities into a number of distinct families. One of these families is known as the sodium:galactoside symporter family (SGF) and currently consists of the following proteins:

  • The melibiose carrier (gene melB) from a variety of enterobacteria. This protein is responsible for melibiose transport and is capable of using hydrogen, sodium, and lithium cations as coupling cations for cotransport.
  • The lactose permease from Lactobacillus (gene lacS or lacY). This protein is responsible for the transport of β-galactosides into the cell, with the concomitant export of a proton. It consists of two domains; a N- terminal SGF domain and a C-terminal domain that resembles that of enzyme IIA of the PEP:sugar phosphotransferase system.
  • The raffinose permease from Pediococcus pentosaceus. It also consists of a N-terminal SGF domain and a C-terminal IIA domain.
  • The glucuronide carrier (gene gusB or uidP) from Escherichia coli.
  • The xylose transporter (gene xylP) from Lactobacillus pentosus.
  • Escherichia coli hypothetical protein yagG.
  • Escherichia coli hypothetical protein yicJ.
  • Escherichia coli hypothetical protein yihO.
  • Escherichia coli hypothetical protein yihP.
  • Bacillus subtilis hypothetical protein yjmB.
  • Bacillus subtilis hypothetical protein ynaJ.

Like sugar transport proteins, these integral membrane proteins are predicted to comprise twelve membrane spanning domains. As a signature pattern we selected a highly conserved region which is located in a cytoplasmic loop between the second and third transmembrane regions. This region starts with a conserved aspartate which has been shown [2], in melB, to be important for the activity of the protein.

Last update:

December 2004 / Pattern and text revised.

Technical section

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

NA_GALACTOSIDE_SYMP, PS00872; Sodium:galactoside symporter family signature  (PATTERN)


References

1AuthorsReizer J., Reizer A., Saier M.H. Jr.
TitleA functional superfamily of sodium/solute symporters.
SourceBiochim. Biophys. Acta 1197:133-166(1994).
PubMed ID8031825

2AuthorsPourcher T., Deckert M., Bassilana M., Leblanc G.
TitleMelibiose permease of Escherichia coli: mutation of aspartic acid 55 in putative helix II abolishes activation of sugar binding by Na+ ions.
SourceBiochem. Biophys. Res. Commun. 178:1176-1181(1991).
PubMed ID1872836



PROSITE is copyright. It is produced by the SIB Swiss Institute Bioinformatics. There are no restrictions on its use by non-profit institutions as long as its content is in no way modified. Usage by and for commercial entities requires a license agreement. For information about the licensing scheme send an email to
Prosite License or see: prosite_license.html.

Miscellaneous

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