title: Structure and Mechanism of Staphylococcus aureus TarS, the Wall Teichoic Acid β-glycosyltransferase Involved in Methicillin Resistance.
abstract: 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.
authors.affiliation: Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Solmaz
authors.initials: S
authors.lastname: Sobhanifar
authors.affiliation: Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Liam J
authors.initials: LJ
authors.lastname: Worrall
authors.affiliation: Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Dustin T
authors.initials: DT
authors.lastname: King
authors.affiliation: Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Wasney
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Lars
authors.initials: L
authors.lastname: Baumann
authors.affiliation: Department of Chemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Robert T
authors.initials: RT
authors.lastname: Gale
authors.affiliation: Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0003-2408-3050
authors.initials: M
authors.lastname: Nosella
authors.affiliation: Department of Chemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Brown
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Withers
authors.affiliation: Department of Biochemistry and Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Natalie C J
authors.initials: NC
authors.lastname: Strynadka
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D002473:Cell Wall; D002853:Chromatography, Liquid; D018360:Crystallography, X-Ray; D016695:Glycosyltransferases / Q000737:chemistry* / Q000378:metabolism*; D013058:Mass Spectrometry; D016106:Methicillin Resistance / Q000502:physiology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000737:chemistry / Q000378:metabolism*; D055550:Protein Stability; D020836:Protein Structure, Quaternary; D013682:Teichoic Acids / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D013682:Teichoic Acids; D016695:Glycosyltransferases