1. Structure and Mechanism of Staphylococcus aureus TarS, the Wall Teichoic Acid β-glycosyltransferase Involved in Methicillin Resistance
- Author
-
Stephen G. Withers, Solmaz Sobhanifar, Lars Baumann, Eric D. Brown, Robert T. Gale, Gregory A. Wasney, Natalie C. J. Strynadka, Michael Nosella, Liam J. Worrall, and Dustin T. King
- Subjects
0301 basic medicine ,Staphylococcus ,Petroleum Products ,medicine.disease_cause ,Crystallography, X-Ray ,Biochemistry ,Bacterial cell structure ,Mass Spectrometry ,chemistry.chemical_compound ,Protein structure ,Cell Wall ,Biology (General) ,Pathology and laboratory medicine ,Teichoic acid ,Crystallography ,biology ,Protein Stability ,Physics ,Medical microbiology ,Condensed Matter Physics ,Enzyme structure ,3. Good health ,Enzymes ,Petroleum ,Staphylococcus aureus ,Physical Sciences ,Crystal Structure ,Organic Materials ,Pathogens ,Research Article ,Methicillin-Resistant Staphylococcus aureus ,QH301-705.5 ,030106 microbiology ,Immunology ,Protein domain ,Materials Science ,Microbiology ,Cell wall ,03 medical and health sciences ,Protein Domains ,Bacterial Proteins ,Transferases ,Virology ,Microbial Control ,Genetics ,medicine ,Solid State Physics ,Protein Structure, Quaternary ,Molecular Biology ,Medicine and health sciences ,Pharmacology ,Biology and life sciences ,Bacteria ,Organisms ,Active site ,Glycosyltransferases ,Proteins ,RC581-607 ,Microbial pathogens ,Teichoic Acids ,030104 developmental biology ,chemistry ,Antibiotic Resistance ,Enzyme Structure ,biology.protein ,Enzymology ,Tar ,Parasitology ,Bacterial pathogens ,Methicillin Resistance ,Antimicrobial Resistance ,Immunologic diseases. Allergy ,Chromatography, Liquid - 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., Author Summary Historically, β-lactam class antibiotics such as methicillin have been very successful in the treatment of bacterial infections, effectively destroying bacteria by rupturing their cell walls while posing little harm to the human organism. In recent years, however, the alarming emergence of Methicillin Resistant S. aureus or MRSA has resulted in a world-wide health crisis, calling on new strategies to combat pathogenesis and antibiotic resistance. As such, understanding the pathways and players that orchestrate resistance is important for overcoming these mechanisms and restoring our powerful β-lactam antibiotic arsenal. In this article we describe the crystal structure of TarS, an enzyme responsible for the glycosylation of wall teichoic acid polymers of the S. aureus cell wall, a process that has been shown to be specifically responsible for methicillin resistance in MRSA. TarS is therefore a promising drug target whose inhibition in combinational therapies would result in MRSA re-sensitization to β-lactam antibiotics. Here we present the first structure of TarS together with several snap-shots of its substrate/product complexes, and elucidate important catalytic features that are valuable for rational drug design efforts to combat resistance in MRSA.
- Published
- 2016