This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Mudrak, B.
Right arrow Articles by Kuehn, M. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Mudrak, B.
Right arrow Articles by Kuehn, M. J.

 Previous Article  |  Next Article 

Journal of Bacteriology, May 2009, p. 2917-2925, Vol. 191, No. 9
0021-9193/09/$08.00+0     doi:10.1128/JB.01622-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Residues of Heat-Labile Enterotoxin Involved in Bacterial Cell Surface Binding{triangledown} ,§

Benjamin Mudrak,1 Daniel L. Rodriguez,2 and Meta J. Kuehn1,2*

Departments of Molecular Genetics and Microbiology,1 Biochemistry, Duke University Medical Center, Durham, North Carolina 277102

Received 14 November 2008/ Accepted 19 February 2009

Enterotoxigenic Escherichia coli (ETEC) is a leading cause of traveler's diarrhea worldwide. One major virulence factor released by this pathogen is the heat-labile enterotoxin LT, which upsets the balance of electrolytes in the intestine. After export, LT binds to lipopolysaccharide (LPS) on the bacterial surface. Although the residues responsible for LT's binding to its host receptor are known, the portion of the toxin which mediates LPS binding has not been defined previously. Here, we describe mutations in LT that impair the binding of the toxin to the external surface of E. coli without altering holotoxin assembly. One mutation in particular, T47A, nearly abrogates surface binding without adversely affecting expression or secretion in ETEC. Interestingly, T47A is able to bind mutant E. coli expressing highly truncated forms of LPS, indicating that LT binding to wild-type LPS may be due primarily to association with an outer core sugar. Consequently, we have identified a region of LT distinct from the pocket involved in eukaryotic receptor binding that is responsible for binding to the surface of E. coli.

* Corresponding author. Mailing address: Box 3711, Duke University Medical Center, Department of Biochemistry, Durham, NC 27710. Phone: (919) 684-2545. Fax: (919) 684-8885. E-mail: mkuehn{at}biochem.duke.edu

{triangledown} Published ahead of print on 6 March 2009.

§ Supplemental material for this article may be found at http://jb.asm.org/.

Journal of Bacteriology, May 2009, p. 2917-2925, Vol. 191, No. 9
0021-9193/09/$08.00+0     doi:10.1128/JB.01622-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Zhang, C., Rausch, D., Zhang, W. (2009). Little Heterogeneity among Genes Encoding Heat-Labile and Heat-Stable Toxins of Enterotoxigenic Escherichia coli Strains Isolated from Diarrheal Pigs. Appl. Environ. Microbiol. 75: 6402-6405 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»