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

J. Biol. Chem., Vol. 283, Issue 41, 27937-27946, October 10, 2008

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 283/41/27937    most recent M801207200v1 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 Google Scholar Google Scholar Articles by Olivier, N. B. Articles by Imperiali, B. Search for Related Content PubMed PubMed Citation Articles by Olivier, N. B. Articles by Imperiali, B. Social Bookmarking                      What's this?

Crystal Structure and Catalytic Mechanism of PglD from Campylobacter jejuni^*

From the Departments of Chemistry and Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139

The carbohydrate 2, 4-diacetamido-2, 4, 6-trideoxy--D-glucopyranose (BacAc₂) is found in a variety of eubacterial pathogens. In Campylobacter jejuni, PglD acetylates the C4 amino group on UDP-2-acetamido-4-amino-2, 4, 6-trideoxy--D-glucopyranose (UDP-4-amino-sugar) to form UDP-BacAc₂. Sequence analysis predicts PglD to be a member of the left-handed β helix family of enzymes. However, poor sequence homology between PglD and left-handed β helix enzymes with existing structural data precludes unambiguous identification of the active site. The co-crystal structures of PglD in the presence of citrate, acetyl coenzyme A, or the UDP-4-amino-sugar were solved. The biological assembly is a trimer with one active site formed between two protomers. Residues lining the active site were identified, and results from functional assays on alanine mutants suggest His-125 is critical for catalysis, whereas His-15 and His-134 are involved in substrate binding. These results are discussed in the context of implications for proteins homologous to PglD in other pathogens.

Received for publication, February 13, 2008 , and in revised form, June 9, 2008.

The atomic coordinates and structure factors (codes 3BSS, 3BSY, and 3BSW) have been deposited in the Protein Data Bank, Research Collaboratory for Structural Bioinformatics, Rutgers University, New Brunswick, NJ (http://www.rcsb.org/).

^* This work was supported, in whole or in part, by National Institutes of Health Grant Post-doctoral Fellowship F32GM075415 (NIGMS; to N. B. O.) and Grant GM39334 (to B. I.). 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 supplemental Figs. S1-S3.

¹ To whom correspondence should be addressed: MIT, 77 Massachusetts Ave., 18-590, Cambridge, MA 02090. Fax: 617-452-2419; E-mail: imper{at}mit.edu.

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