3I8A

Staphylococcus aureus H30N, F98Y Dihydrofolate Reductase complexed with NADPH and 2,4-diamino-5-(3-(2,5-dimethoxyphenyl)prop-1-ynyl)-6-ethylpyrimidine (UCP120B)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.41 Å
  • R-Value Free: 0.261 
  • R-Value Work: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Towards the understanding of resistance mechanisms in clinically isolated trimethoprim-resistant, methicillin-resistant Staphylococcus aureus dihydrofolate reductase.

Frey, K.M.Lombardo, M.N.Wright, D.L.Anderson, A.C.

(2010) J.Struct.Biol. 170: 93-97

  • DOI: 10.1016/j.jsb.2009.12.011

  • PubMed Abstract: 
  • Resistance to therapeutics such as trimethoprim-sulfamethoxazole has become an increasing problem in strains of methicillin-resistant Staphylococcus aureus (MRSA). Clinically isolated trimethoprim-resistant strains reveal a double mutation, H30N/F98Y ...

    Resistance to therapeutics such as trimethoprim-sulfamethoxazole has become an increasing problem in strains of methicillin-resistant Staphylococcus aureus (MRSA). Clinically isolated trimethoprim-resistant strains reveal a double mutation, H30N/F98Y, in dihydrofolate reductase (DHFR). In order to develop novel and effective therapeutics against these resistant strains, we evaluated a series of propargyl-linked antifolate lead compounds for inhibition of the mutant enzyme. For the propargyl-linked antifolates, the F98Y mutation generates minimal (between 1.2- and 6-fold) losses of affinity and the H30N mutation generates greater losses (between 2.4- and 48-fold). Conversely, trimethoprim affinity is largely diminished by the F98Y mutation (36-fold) and is not affected by the H30N mutation. In order to elucidate a mechanism of resistance, we determined a crystal structure of a complex of this double mutant with a lead propargyl-linked antifolate. This structure suggests a resistance mechanism consistent both for the propargyl-linked class of antifolates and for trimethoprim that is based on the loss of a conserved water-mediated hydrogen bond.


    Organizational Affiliation

    Department of Pharmaceutical Sciences, University of Connecticut, 69 N. Eagleville Rd., Storrs, CT 06269, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Dihydrofolate reductase
X
157Staphylococcus aureusMutation(s): 2 
Gene Names: folA
EC: 1.5.1.3
Find proteins for P0A017 (Staphylococcus aureus)
Go to UniProtKB:  P0A017
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
N22
Query on N22

Download SDF File 
Download CCD File 
X
5-[3-(2,5-dimethoxyphenyl)prop-1-yn-1-yl]-6-ethylpyrimidine-2,4-diamine
C17 H20 N4 O2
NNFDQABYXZBKRK-UHFFFAOYSA-N
 Ligand Interaction
NDP
Query on NDP

Download SDF File 
Download CCD File 
X
NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE
C21 H30 N7 O17 P3
ACFIXJIJDZMPPO-NNYOXOHSSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
N22Ki: 120 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.41 Å
  • R-Value Free: 0.261 
  • R-Value Work: 0.206 
  • Space Group: P 61 2 2
Unit Cell:
Length (Å)Angle (°)
a = 79.164α = 90.00
b = 79.164β = 90.00
c = 108.960γ = 120.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
HKL-2000data reduction
REFMACrefinement
CBASSdata collection
Cootmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-02-09
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2013-11-20
    Type: Non-polymer description