HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 280, Issue 34, 30310-30319, August 26, 2005

This Article Full Text Full Text (PDF) Supplemental data All Versions of this Article: 280/34/30310    most recent M504371200v1 Submit a Letter to Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Cuthbertson, L. Articles by Whitfield, C. Search for Related Content PubMed PubMed Citation Articles by Cuthbertson, L. Articles by Whitfield, C. Social Bookmarking                      What's this?

The C-terminal Domain of the Nucleotide-binding Domain Protein Wzt Determines Substrate Specificity in the ATP-binding Cassette Transporter for the Lipopolysaccharide O-antigens in Escherichia coli Serotypes O8 and O9a^*

Leslie Cuthbertson, Jacqueline Powers, and Chris Whitfield, Recipient of a Tier 1 Canada Research Chair¶

From the Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada

The polymannan O-antigenic polysaccharides (O-PSs) of Escherichia coli O8 and O9a are synthesized via an ATP-binding cassette (ABC) transporter-dependent pathway. The group 2 capsular polysaccharides of E. coli serve as prototypes for polysaccharide synthesis and export via this pathway. Here, we show that there are some fundamental differences between the ABC transporter-dependent pathway for O-PS biosynthesis and the capsular polysaccharide paradigm. In the capsule system, mutants lacking the ABC transporter are viable, and membranes isolated from these strains are no longer able to synthesize polymer using an endogenous acceptor. In contrast, E. coli strains carrying mutations in the membrane component (Wzm) and/or the nucleotide-binding component (Wzt) of the O8 and O9a polymannan transporters are nonviable under conditions permissive to O-PS biosynthesis and take on an aberrant elongated cell morphology. Whereas the ABC transporters for capsular polysaccharides with different structures are functionally interchangeable, the O8 and O9a exporters are specific for their cognate polymannan substrates. The E. coli O8 and O9a Wzt proteins contain a C-terminal domain not present in the corresponding nucleotide-binding protein (KpsT) from the capsule exporter. Whereas the Wzm components are functionally interchangeable, albeit with reduced efficiency, the Wzt components are not, indicating a specific role for Wzt in substrate specificity. Chimeric Wzt proteins were constructed in order to localize the region involved in substrate specificity to the C-terminal domain.

Received for publication, April 21, 2005 , and in revised form, June 2, 2005.

^* This work was supported by Canadian Institutes of Health Research Grant MOP-62877 (to C. W.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The on-line version of this article (available at http://www.jbc.org) contains Tables 2 and 3.

Recipient of a Postgraduate Scholarship (PGS-A) from the Natural Sciences and Engineering Research Council.

Recipient of a Canadian Institutes for Health Research Postdoctoral Fellowship.

^¶ To whom correspondence should be addressed: Dept. of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada. Tel.: 519-824-4120 (ext. 53361); Fax: 519-837-1802; E-mail: cwhitfie{at}uoguelph.ca.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				A. Lerner, Y. Okon, and S. Burdman The wzm gene located on the pRhico plasmid of Azospirillum brasilense Sp7 is involved in lipopolysaccharide synthesis Microbiology, March 1, 2009; 155(3): 791 - 804. [Abstract] [Full Text] [PDF]

				V. Kos, L. Cuthbertson, and C. Whitfield The Klebsiella pneumoniae O2a Antigen Defines a Second Mechanism for O Antigen ATP-binding Cassette Transporters J. Biol. Chem., January 30, 2009; 284(5): 2947 - 2956. [Abstract] [Full Text] [PDF]

				K. Steiner, R. Novotny, D. B. Werz, K. Zarschler, P. H. Seeberger, A. Hofinger, P. Kosma, C. Schaffer, and P. Messner Molecular Basis of S-layer Glycoprotein Glycan Biosynthesis in Geobacillus stearothermophilus J. Biol. Chem., July 25, 2008; 283(30): 21120 - 21133. [Abstract] [Full Text] [PDF]

				A. L. Davidson, E. Dassa, C. Orelle, and J. Chen Structure, Function, and Evolution of Bacterial ATP-Binding Cassette Systems Microbiol. Mol. Biol. Rev., June 1, 2008; 72(2): 317 - 364. [Abstract] [Full Text] [PDF]

				L. Cuthbertson, M. S. Kimber, and C. Whitfield Substrate binding by a bacterial ABC transporter involved in polysaccharide export PNAS, December 4, 2007; 104(49): 19529 - 19534. [Abstract] [Full Text] [PDF]

				S. Berg, D. Kaur, M. Jackson, and P. J Brennan The glycosyltransferases of Mycobacterium tuberculosis--roles in the synthesis of arabinogalactan, lipoarabinomannan, and other glycoconjugates Glycobiology, June 1, 2007; 17(6): 35R - 56R. [Abstract] [Full Text] [PDF]

				M. A. D'Elia, M. P. Pereira, Y. S. Chung, W. Zhao, A. Chau, T. J. Kenney, M. C. Sulavik, T. A. Black, and E. D. Brown Lesions in Teichoic Acid Biosynthesis in Staphylococcus aureus Lead to a Lethal Gain of Function in the Otherwise Dispensable Pathway. J. Bacteriol., June 1, 2006; 188(12): 4183 - 4189. [Abstract] [Full Text] [PDF]

				M. Wacker, M. F. Feldman, N. Callewaert, M. Kowarik, B. R. Clarke, N. L. Pohl, M. Hernandez, E. D. Vines, M. A. Valvano, C. Whitfield, et al. Substrate specificity of bacterial oligosaccharyltransferase suggests a common transfer mechanism for the bacterial and eukaryotic systems PNAS, May 2, 2006; 103(18): 7088 - 7093. [Abstract] [Full Text] [PDF]