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 
  • R-Value Observed: 0.208 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.4 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: https://doi.org/10.1016/j.jsb.2009.12.011
  • Primary Citation of Related Structures:  
    3I8A

  • 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, 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:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Dihydrofolate reductaseA [auth X]157Staphylococcus aureusMutation(s): 2 
Gene Names: dfrBfolA
EC: 1.5.1.3
UniProt
Find proteins for P0A017 (Staphylococcus aureus)
Explore P0A017 
Go to UniProtKB:  P0A017
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0A017
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
NDP
Query on NDP

Download Ideal Coordinates CCD File 
C [auth X]NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE
C21 H30 N7 O17 P3
ACFIXJIJDZMPPO-NNYOXOHSSA-N
N22
Query on N22

Download Ideal Coordinates CCD File 
B [auth X]5-[3-(2,5-dimethoxyphenyl)prop-1-yn-1-yl]-6-ethylpyrimidine-2,4-diamine
C17 H20 N4 O2
NNFDQABYXZBKRK-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.41 Å
  • R-Value Free: 0.261 
  • R-Value Work: 0.206 
  • R-Value Observed: 0.208 
  • Space Group: P 61 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 79.164α = 90
b = 79.164β = 90
c = 108.96γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
PDB_EXTRACTdata extraction
CBASSdata collection
HKL-2000data reduction
SCALEPACKdata scaling
Cootmodel building

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-02-09
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2013-11-20
    Changes: Non-polymer description
  • Version 1.3: 2021-10-13
    Changes: Database references, Derived calculations
  • Version 1.4: 2023-09-06
    Changes: Data collection, Refinement description