Editor: Klaus Hantke
Membrane topology of the Salmonella enterica serovar Typhimurium Group B O-antigen translocase Wzx
Article first published online: 14 AUG 2008
© 2008 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Letters
Volume 287, Issue 1, pages 76–84, October 2008
How to Cite
Cunneen, M. M. and Reeves, P. R. (2008), Membrane topology of the Salmonella enterica serovar Typhimurium Group B O-antigen translocase Wzx. FEMS Microbiology Letters, 287: 76–84. doi: 10.1111/j.1574-6968.2008.01295.x
- Issue published online: 1 SEP 2008
- Article first published online: 14 AUG 2008
- Received 3 July 2008; accepted 8 July 2008.First published online 14 August 2008.
- O antigen;
- membrane topology
The O-antigen translocase, Wzx, is involved in translocation of bacterial polysaccharide repeat units across the cytoplasmic membrane, and is an unusually diverse, highly hydrophobic protein, with high numbers of predicted α-helical transmembrane segments (TMS). The Salmonella enterica serovar Typhimurium Group B O-antigen Wzx was an ideal candidate for topological study as the O-antigen gene cluster is one of only a few that have been well characterized. The topology profile prediction for this protein was determined using five programs, with different recognition parameters, which consistently predict that 12 TMS are present. A membrane topology model was constructed by analysis of lacZ and phoA gene fusions at randomly selected and targeted fusion sites within wzx. Enzyme activity of these, and full-length C-terminal fusion proteins, confirmed the 12-TMS topology for this Wzx, and also indicated that the C-terminus was located within the cytoplasm, which is consistent with the predicted topology.