3CLB

Structure of bifunctional TcDHFR-TS in complex with TMQ


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.00 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.209 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structure-based approach to pharmacophore identification, in silico screening, and three-dimensional quantitative structure-activity relationship studies for inhibitors of Trypanosoma cruzi dihydrofolate reductase function.

Schormann, N.Senkovich, O.Walker, K.Wright, D.L.Anderson, A.C.Rosowsky, A.Ananthan, S.Shinkre, B.Velu, S.Chattopadhyay, D.

(2008) Proteins 73: 889-901

  • DOI: 10.1002/prot.22115
  • Primary Citation of Related Structures:  
    3CL9, 3CLB, 2H2Q

  • PubMed Abstract: 
  • We have employed a structure-based three-dimensional quantitative structure-activity relationship (3D-QSAR) approach to predict the biochemical activity for inhibitors of T. cruzi dihydrofolate reductase-thymidylate synthase (DHFR-TS). Crystal struct ...

    We have employed a structure-based three-dimensional quantitative structure-activity relationship (3D-QSAR) approach to predict the biochemical activity for inhibitors of T. cruzi dihydrofolate reductase-thymidylate synthase (DHFR-TS). Crystal structures of complexes of the enzyme with eight different inhibitors of the DHFR activity together with the structure in the substrate-free state (DHFR domain) were used to validate and refine docking poses of ligands that constitute likely active conformations. Structural information from these complexes formed the basis for the structure-based alignment used as input for the QSAR study. Contrary to indirect ligand-based approaches the strategy described here employs a direct receptor-based approach. The goal is to generate a library of selective lead inhibitors for further development as antiparasitic agents. 3D-QSAR models were obtained for T. cruzi DHFR-TS (30 inhibitors in learning set) and human DHFR (36 inhibitors in learning set) that show a very good agreement between experimental and predicted enzyme inhibition data. For crossvalidation of the QSAR model(s), we have used the 10% leave-one-out method. The derived 3D-QSAR models were tested against a few selected compounds (a small test set of six inhibitors for each enzyme) with known activity, which were not part of the learning set, and the quality of prediction of the initial 3D-QSAR models demonstrated that such studies are feasible. Further refinement of the models through integration of additional activity data and optimization of reliable docking poses is expected to lead to an improved predictive ability.


    Organizational Affiliation

    Department of Pharmaceutical Sciences, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
DHFR-TSABCD521Trypanosoma cruziMutation(s): 0 
EC: 1.5.1.3 (PDB Primary Data), 2.1.1.45 (PDB Primary Data)
Find proteins for Q27793 (Trypanosoma cruzi)
Explore Q27793 
Go to UniProtKB:  Q27793
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAP
Query on NAP

Download CCD File 
A, B, C, D
NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE
C21 H28 N7 O17 P3
XJLXINKUBYWONI-NNYOXOHSSA-N
 Ligand Interaction
TMQ
Query on TMQ

Download CCD File 
A, B, C, D
TRIMETREXATE
C19 H24 N5 O3
NOYPYLRCIDNJJB-UHFFFAOYSA-O
 Ligand Interaction
SO4
Query on SO4

Download CCD File 
A, C, D
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
EDO
Query on EDO

Download CCD File 
A, B, C, D
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.00 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.209 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 176.571α = 90
b = 176.571β = 90
c = 251.848γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data collection
DENZOdata reduction
SCALEPACKdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-01-06
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance