1XAN

HUMAN GLUTATHIONE REDUCTASE IN COMPLEX WITH A XANTHENE INHIBITOR


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Work: 0.158 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Kinetics and crystallographic analysis of human glutathione reductase in complex with a xanthene inhibitor.

Savvides, S.N.Karplus, P.A.

(1996) J.Biol.Chem. 271: 8101-8107


  • PubMed Abstract: 
  • We have determined the crystal structure of a complex between the noncompetitive inhibitor (Kis = 27 microM, Kii = 48 microM with respect to oxidized glutathione (GSSG) and Kis = 144 microM, Kii = 176 microM with respect to NADPH) 6-hydroxy-3-oxo-3H- ...

    We have determined the crystal structure of a complex between the noncompetitive inhibitor (Kis = 27 microM, Kii = 48 microM with respect to oxidized glutathione (GSSG) and Kis = 144 microM, Kii = 176 microM with respect to NADPH) 6-hydroxy-3-oxo-3H-xanthene-9-propionic acid (XAN) and human glutathione reductase (hGR). The structure, refined to an R-factor of 0.158 at 2.0 A resolution, reveals XAN bound in the large cavity present at the hGR dimer interface where it does not overlap the glutathione binding site. The inhibitor binding causes extensive local structural changes that primarily involve amino acid residues from a 30-residue alpha-helix that lines the cavity and contributes to the active site of hGR. Despite the lack of physical overlap of XAN with the GSSG binding site, no GSSG binding is seen in soaks carried out with high XAN and GSSG concentrations, suggesting that some subtle interaction between the sites exists. An earlier crystallographic analysis on the complex between hGR and 3,7-diamino-2,8-dimethyl-5-phenyl-phenazinium chloride (safranin) showed that safranin bound at this same site. We have found that safranin also inhibits hGR in a noncompetitive fashion, but it binds about 16 times less tightly (Kis = 453 microM, Kii = 586 microM with respect to GSSG) than XAN and does not preclude the binding of GSSG in the crystal. Although in structure-based drug design competitive inhibitors are usually targetted, XAN's binding to a well defined site that is unique to glutathione reductase suggests that noncompetitive inhibitors could also serve as lead compounds for structure-based drug design, in particular as components of chimeric inhibitors.


    Organizational Affiliation

    Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, New York 14853, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GLUTATHIONE REDUCTASE
A
461Homo sapiensMutation(s): 0 
Gene Names: GSR (GLUR, GRD1)
EC: 1.8.1.7
Find proteins for P00390 (Homo sapiens)
Go to Gene View: GSR
Go to UniProtKB:  P00390
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HXP
Query on HXP

Download SDF File 
Download CCD File 
A
3,6-DIHYDROXY-XANTHENE-9-PROPIONIC ACID
C16 H14 O5
PFQGLFBMMPZYEU-UHFFFAOYSA-N
 Ligand Interaction
FAD
Query on FAD

Download SDF File 
Download CCD File 
A
FLAVIN-ADENINE DINUCLEOTIDE
C27 H33 N9 O15 P2
VWWQXMAJTJZDQX-UYBVJOGSSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Work: 0.158 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 119.790α = 90.00
b = 63.350β = 58.61
c = 84.650γ = 90.00
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
X-PLORphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1996-07-11
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance