Structure and Mechanism of Staphylococcus aureus TarS, the Wall Teichoic Acid β-glycosyltransferase Involved in Methicillin Resistance

PLoS Pathogens

Michael Nosella¹  Dustin T. King¹  Solmaz Sobhanifar¹  Gregory A. Wasney¹  Natalie C. J. Strynadka¹  Liam J. Worrall¹  Eric D. Brown²  Robert T. Gale²  Lars Baumann³  Stephen G. Withers³ 

[1] Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada;Department of Chemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada;Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada

关键词: Tar;    Crystal structure;    Methicillin-resistant Staphylococcus aureus;    Staphylococcus aureus;    Enzyme structure;    Glycosyltransferases;    Antibiotic resistance;    Protein domains;   

DOI  :  10.1371/journal.ppat.1006067

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

In recent years, there has been a growing interest in teichoic acids as targets for antibiotic drug design against major clinical pathogens such as Staphylococcus aureus, reflecting the disquieting increase in antibiotic resistance and the historical success of bacterial cell wall components as drug targets. It is now becoming clear that β-O-GlcNAcylation of S. aureus wall teichoic acids plays a major role in both pathogenicity and antibiotic resistance. Here we present the first structure of S. aureus TarS, the enzyme responsible for polyribitol phosphate β-O-GlcNAcylation. Using a divide and conquer strategy, we obtained crystal structures of various TarS constructs, mapping high resolution overlapping N-terminal and C-terminal structures onto a lower resolution full-length structure that resulted in a high resolution view of the entire enzyme. Using the N-terminal structure that encapsulates the catalytic domain, we furthermore captured several snapshots of TarS, including the native structure, the UDP-GlcNAc donor complex, and the UDP product complex. These structures along with structure-guided mutants allowed us to elucidate various catalytic features and identify key active site residues and catalytic loop rearrangements that provide a valuable platform for anti-MRSA drug design. We furthermore observed for the first time the presence of a trimerization domain composed of stacked carbohydrate binding modules, commonly observed in starch active enzymes, but adapted here for a poly sugar-phosphate glycosyltransferase.

【 授权许可】

CC BY