1DAJ

COMPARISON OF TERNARY COMPLEXES OF PNEUMOCYSTIS CARINII AND WILD TYPE HUMAN DIHYDROFOLATE REDUCTASE WITH COENZYME NADPH AND A NOVEL CLASSICAL ANTITUMOR FURO[2,3D]PYRIMIDINE ANTIFOLATE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Work: 0.181 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Comparison of ternary complexes of Pneumocystis carinii and wild-type human dihydrofolate reductase with coenzyme NADPH and a novel classical antitumor furo[2,3-d]pyrimidine antifolate.

Cody, V.Galitsky, N.Luft, J.R.Pangborn, W.Gangjee, A.Devraj, R.Queener, S.F.Blakley, R.L.

(1997) Acta Crystallogr.,Sect.D 53: 638-649

  • DOI: 10.1107/S090744499700509X

  • PubMed Abstract: 
  • The novel furopyrimidine N-(4-{N-[(2,4-diaminofuro[2,3-d]pyrimidin-5-yl)methyl]methylamino}benzoyl)-L- glutamate (MTXO), a classical antifolate with antitumor activity comparable to that of methotrexate (MTX), has been studied as inhibitor-cofactor t ...

    The novel furopyrimidine N-(4-{N-[(2,4-diaminofuro[2,3-d]pyrimidin-5-yl)methyl]methylamino}benzoyl)-L- glutamate (MTXO), a classical antifolate with antitumor activity comparable to that of methotrexate (MTX), has been studied as inhibitor-cofactor ternary crystal complexes with wild-type Pneumocystis carinii (pc) and recombinant human wild-type dihydrofolate reductase (hDHFR). These structural data provide the first direct comparison of the binding interactions of the same antifolate inhibitor in the active site for pc and human DHFR. The human ternary DHFR complex crystallizes in the rhombohedral space group R3 and is isomorphous to the ternary complex reported for a gamma-tetrazole methotrexate analogue, MTXT. The pcDHFR complex crystallizes in the monoclinic space group P2(1) and is isomorphous to that reported for a trimethoprim (TMP) complex. Interpretation of difference Fourier electron-density maps for these ternary complexes revealed that MTXO binds with its 2,4-diaminofuropyrimidine ring interacting with Glu32 in pc and Glu30 in human DHFR, as observed for MTXT. The presence of the 6-5 furopyrimidine ring instead of the 6-6 pteridine ring results in a different bridge conformation compared with that of MTXT. The bridge torsion angles for MTXO, i.e. C(4a)-C(5)-C(8)-N(9) and C(5)-C(8)-N(9)-C(1'), are -156.5/51.9 degrees and -162.6/51.8 degrees, respectively for h and pc, compared with -146.8/57.4 degrees for MTXT. In each case, the p-aminobenzoylglutamate conformation is similar to that observed for MTXT. In the pcDHFR complex, the active-site region is conserved and the additional 20 residues in the sequence compared with the human enzyme are located in external loop regions. There is a significant change in the nicotinamide ribose conformation of the cofactor which places the nicotinamide O atom close to the 4NH(2) group of MTXO (2.7 A), a shift not observed in hDHFR structures. As a consequence of this, there is a loss of a hydrogen bond between the nicotinamide carbonyl group and the backbone of Ala12 in pcDHFR. In the human ternary complexes, the cofactor NADPH is bound with a more extended conformation, and the nicotinamide O atom makes a 3.5 A contact with the 4NH(2) group of MTXO. Although the novel classical antifolate MTXO is not highly active against pcDHFR, there are correlations between its binding interactions consistent with its lower potency as an inhibitor of h and pcDHFR compared with MTX.


    Related Citations: 
    • The Structure of Pneumocystis Carinii Dihydrofolate Reductase to 1.9 A Resolution
      Champness, J.N.,Achari, A.,Ballantine, S.P.,Bryant, P.K.,Delves, C.J.,Stammers, D.K.
      (1994) Structure 2: 915


    Organizational Affiliation

    Hauptman-Woodward Medical Research Institute, Inc., Buffalo, NY 14203, USA. cody@hwi.buffalo.edu




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
DIHYDROFOLATE REDUCTASE
A
206Pneumocystis cariniiEC: 1.5.1.3
Find proteins for P16184 (Pneumocystis carinii)
Go to UniProtKB:  P16184
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MOT
Query on MOT

Download SDF File 
Download CCD File 
A
N-[4-[(2,4-DIAMINOFURO[2,3D]PYRIMIDIN-5-YL)METHYL]METHYLAMINO]-BENZOYL]-L-GLUTAMATE
C20 H22 N6 O6
WXINNGCGSCFUCR-ZDUSSCGKSA-N
 Ligand Interaction
NDP
Query on NDP

Download SDF File 
Download CCD File 
A
NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE
C21 H30 N7 O17 P3
ACFIXJIJDZMPPO-NNYOXOHSSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
COEIC50: 35 nM (100) BINDINGDB
MOTKi: 6.5 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Work: 0.181 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 37.171α = 90.00
b = 43.094β = 94.85
c = 61.049γ = 90.00
Software Package:
Software NamePurpose
R-AXISdata reduction
PROFFTrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1997-12-24
    Type: Initial release
  • Version 1.1: 2008-03-03
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance