2QK8

Crystal structure of the anthrax drug target, Bacillus anthracis dihydrofolate reductase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.243 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Crystal structure of the anthrax drug target, Bacillus anthracis dihydrofolate reductase.

Bennett, B.C.Xu, H.Simmerman, R.F.Lee, R.E.Dealwis, C.G.

(2007) J.Med.Chem. 50: 4374-4381

  • DOI: 10.1021/jm070319v

  • PubMed Abstract: 
  • Spores of Bacillus anthracis are the infectious agent of anthrax. Current antibiotic treatments are limited due to resistance and patient age restrictions; thus, additional targets for therapeutic intervention are needed. One possible candidate is di ...

    Spores of Bacillus anthracis are the infectious agent of anthrax. Current antibiotic treatments are limited due to resistance and patient age restrictions; thus, additional targets for therapeutic intervention are needed. One possible candidate is dihydrofolate reductase (DHFR), a biosynthetic enzyme necessary for anthrax pathogenicity. We determined the crystal structure of DHFR from B. anthracis (baDHFR) in complex with methotrexate (MTX; 1) at 2.4 Angstrom resolution. The structure reveals the crucial interactions required for MTX binding and a putative molecular basis for how baDHFR has natural resistance to trimethoprim (TMP; 2). The structure also allows insights for designing selective baDHFR inhibitors that will have weak affinities for the human enzyme. Additionally, we have found that 5-nitro-6-methylamino-isocytosine (MANIC; 3), which inhibits another B. anthracis folate synthesis enzyme, dihydropteroate synthase (DHPS), can also inhibit baDHFR. This provides a starting point for designing multi-target inhibitors that are less likely to induce drug resistance.


    Organizational Affiliation

    Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Dihydrofolate reductase
A
162Bacillus anthracisGene Names: dfrA (dfrD)
EC: 1.5.1.3
Find proteins for Q81R22 (Bacillus anthracis)
Go to UniProtKB:  Q81R22
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MTX
Query on MTX

Download SDF File 
Download CCD File 
A
METHOTREXATE
C20 H22 N8 O5
FBOZXECLQNJBKD-ZDUSSCGKSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
MTXIC50: 12.2 - 24 nM (100) BINDINGDB
MTXIC50: ~20 nM BINDINGMOAD
MTXIC50: 12.2 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.243 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 82.697α = 90.00
b = 41.236β = 119.20
c = 67.032γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
PHASERphasing
HKL-2000data reduction
BioCARSdata collection
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-08-28
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Source and taxonomy, Version format compliance