Candida albicans dihydrofolate reductase complexed with dihydro-nicotinamide-adenine-dinucleotide phosphate (NADPH) and 5-(PHENYLSULFANYL)-2,4-QUINAZOLINEDIAMINE (GW997)

Experimental Data Snapshot

  • Resolution: 1.70 Å
  • R-Value Work: 0.156 
  • R-Value Observed: 0.156 

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This is version 1.4 of the entry. See complete history


X-ray Crystal Structures of Candida albicans Dihydrofolate Reductase: High Resolution Ternary Complexes in Which the Dihydronicotinamide Moiety of NADPH is Displaced by an inhibitor

Whitlow, M.Howard, A.J.Stewart, D.Hardman, K.D.Chan, J.H.Baccanari, D.P.Tansik, R.L.Hong, J.S.Kuyper, L.F.

(2001) J Med Chem 44: 2928-2932

  • DOI: https://doi.org/10.1021/jm0101444
  • Primary Citation of Related Structures:  
    1IA1, 1IA2, 1IA3, 1IA4

  • PubMed Abstract: 

    X-ray crystallographic analysis of 5-(4'-substituted phenyl)sulfanyl-2,4-diaminoquinazoline inhibitors in ternary complex with Candida albicans dihydrofolate reductase (DHFR) and NADPH revealed two distinct modes of binding. The two compounds with small 4'-substituents (H and CH3) were found to bind with the phenyl group oriented in the plane of the quinazoline ring system and positioned adjacent to the C-helix. In contrast, the more selective inhibitors with larger 4'-substituents (tert-butyl and N-morpholino) were bound to the enzyme with the phenyl group perpendicular to the quinazoline ring and positioned in the region of the active site that typically binds the dihydronicotinamide moiety of NADPH. The cofactor appeared bound to DHFR but with the disordered dihydronicotinamide swung away from the protein surface and into solution. This unusual inhibitor binding mode may play an important role in the high DHFR selectivity of these compounds and also may provide new ideas for inhibitor design.

  • Organizational Affiliation

    GlaxoSmithKline, Inc., Five Moore Drive, Research Triangle Park, North Carolina 27709, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
192Candida albicansMutation(s): 0 
Gene Names: DFR1
Find proteins for P22906 (Candida albicans)
Explore P22906 
Go to UniProtKB:  P22906
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP22906
Sequence Annotations
  • Reference Sequence
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
TQ3 Binding MOAD:  1IA1 IC50: 34 (nM) from 1 assay(s)
BindingDB:  1IA1 IC50: 34 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 1.70 Å
  • R-Value Work: 0.156 
  • R-Value Observed: 0.156 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 76.91α = 90
b = 67.28β = 93.07
c = 38.49γ = 90
Software Package:
Software NamePurpose
X-GENdata reduction
FRODOmodel building
X-GENdata scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-04-11
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-04
    Changes: Refinement description
  • Version 1.4: 2023-08-09
    Changes: Data collection, Database references, Derived calculations, Refinement description