1MR7

Crystal Structure of Streptogramin A Acetyltransferase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.176 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural Basis of Synercid (Quinupristin-Dalfopristin) Resistance in Gram-positive Bacterial Pathogens

Kehoe, L.E.Snidwongse, J.Courvalin, P.Rafferty, J.B.Murray, I.A.

(2003) J.Biol.Chem. 278: 29963-29970

  • DOI: 10.1074/jbc.M303766200
  • Primary Citation of Related Structures:  1MR9, 1MRL

  • PubMed Abstract: 
  • Synercid, a new semisynthetic streptogramin-derived antibiotic containing dalfopristin and quinupristin, is used in treatment of life-threatening infections caused by glycopeptide-resistant Enterococcus faecium and other bacterial pathogens. However, ...

    Synercid, a new semisynthetic streptogramin-derived antibiotic containing dalfopristin and quinupristin, is used in treatment of life-threatening infections caused by glycopeptide-resistant Enterococcus faecium and other bacterial pathogens. However, dissemination of genes encoding virginiamycin acetyltransferases, enzymes that confer resistance to streptogramins, threatens to limit the medical utility of the quinupristin-dalfopristin combination. Here we present structures of virginiamycin acetyltransferase D (VatD) determined at 1.8 A resolution in the absence of ligands, at 2.8 A resolution bound to dalfopristin, and at 3.0 A resolution in the presence of acetyl-coenzyme A. Dalfopristin is bound by VatD in a similar conformation to that described previously for the streptogramin virginiamycin M1. However, specific interactions with the substrate are altered as a consequence of a conformational change in the pyrollidine ring that is propagated to adjacent constituents of the dalfopristin macrocycle. Inactivation of dalfopristin involves acetyl transfer from acetyl-coenzyme A to the sole (O-18) hydroxy group of the antibiotic that lies close to the side chain of the strictly conserved residue, His-82. Replacement of residue 82 by alanine is accompanied by a fall in specific activity of >105-fold, indicating that the imidazole moiety of His-82 is a major determinant of catalytic rate enhancement by VatD. The structure of the VatD-dalfopristin complex can be used to predict positions where further structural modification of the drug might preclude enzyme binding and thereby circumvent Synercid resistance.


    Organizational Affiliation

    Krebs Institute for Biomolecular Sciences, Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Streptogramin A Acetyltransferase
A, B, C, X, Y, Z
209Enterococcus faeciumGene Names: vatD (satA)
EC: 2.3.1.-
Find proteins for P50870 (Enterococcus faecium)
Go to UniProtKB:  P50870
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.176 
  • Space Group: F 2 2 2
Unit Cell:
Length (Å)Angle (°)
a = 181.393α = 90.00
b = 183.001β = 90.00
c = 184.124γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
REFMACrefinement
SHELXDphasing
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-08-26
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Version format compliance