Download MendeleyPotential for Reduction of Streptogramin A Resistance Revealed by Structural Analysis of Acetyltransferase VatA.
Stogios, P.J., Kuhn, M.L., Evdokimova, E., Courvalin, P., Anderson, W.F., Savchenko, A.(2014) Antimicrob Agents Chemother 58: 7083-7092
- PubMed: 25223995
- DOI: https://doi.org/10.1128/AAC.03743-14
- Primary Citation of Related Structures:
4HUR, 4HUS, 4MYO - PubMed Abstract:
Combinations of group A and B streptogramins (i.e., dalfopristin and quinupristin) are "last-resort" antibiotics for the treatment of infections caused by Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium. Resistance to streptogramins has arisen via multiple mechanisms, including the deactivation of the group A component by the large family of virginiamycin O-acetyltransferase (Vat) enzymes. Despite the structural elucidation performed for the VatD acetyltransferase, which provided a general molecular framework for activity, a detailed characterization of the essential catalytic and antibiotic substrate-binding determinants in Vat enzymes is still lacking. We have determined the crystal structure of S. aureus VatA in apo, virginiamycin M1- and acetyl-coenzyme A (CoA)-bound forms and provide an extensive mutagenesis and functional analysis of the structural determinants required for catalysis and streptogramin A recognition. Based on an updated genomic survey across the Vat enzyme family, we identified key conserved residues critical for VatA activity that are not part of the O-acetylation catalytic apparatus. Exploiting such constraints of the Vat active site may lead to the development of streptogramin A compounds that evade inactivation by Vat enzymes while retaining binding to their ribosomal target.
Organizational Affiliation:
Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada Center for Structural Genomics of Infectious Diseases (CSGID).
