3DK9

Catalytic cycle of human glutathione reductase near 1 A resolution


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 0.95 Å
  • R-Value Free: 0.152 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Catalytic cycle of human glutathione reductase near 1 A resolution.

Berkholz, D.S.Faber, H.R.Savvides, S.N.Karplus, P.A.

(2008) J.Mol.Biol. 382: 371-384

  • DOI: 10.1016/j.jmb.2008.06.083
  • Primary Citation of Related Structures:  3DJG, 3DJJ, 3DK4, 3DK8

  • PubMed Abstract: 
  • Efficient enzyme catalysis depends on exquisite details of structure beyond those resolvable in typical medium- and high-resolution crystallographic analyses. Here we report synchrotron-based cryocrystallographic studies of natural substrate complexe ...

    Efficient enzyme catalysis depends on exquisite details of structure beyond those resolvable in typical medium- and high-resolution crystallographic analyses. Here we report synchrotron-based cryocrystallographic studies of natural substrate complexes of the flavoenzyme human glutathione reductase (GR) at nominal resolutions between 1.1 and 0.95 A that reveal new aspects of its mechanism. Compression in the active site causes overlapping van der Waals radii and distortion in the nicotinamide ring of the NADPH substrate, which enhances catalysis via stereoelectronic effects. The bound NADPH and redox-active disulfide are positioned optimally on opposite sides of the flavin for a 1,2-addition across a flavin double bond. The new structures extend earlier observations to reveal that the redox-active disulfide loop in GR is an extreme case of sequential peptide bonds systematically deviating from planarity--a net deviation of 53 degrees across five residues. But this apparent strain is not a factor in catalysis, as it is present in both oxidized and reduced structures. Intriguingly, the flavin bond lengths in oxidized GR are intermediate between those expected for oxidized and reduced flavin, but we present evidence that this may not be due to the protein environment but instead due to partial synchrotron reduction of the flavin by the synchrotron beam. Finally, of more general relevance, we present evidence that the structures of synchrotron-reduced disulfide bonds cannot generally be used as reliable models for naturally reduced disulfide bonds.


    Organizational Affiliation

    Department of Biochemistry and Biophysics, Oregon State University, 2011 ALS, Corvallis, OR 97331-7305, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Glutathione reductase
A
478Homo sapiensGene 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
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 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: 0.95 Å
  • R-Value Free: 0.152 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 120.357α = 90.00
b = 62.353β = 122.00
c = 84.035γ = 90.00
Software Package:
Software NamePurpose
SHELXrefinement
DENZOdata reduction
PDB_EXTRACTdata extraction
SHELXL-97refinement
CNSphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-08-05
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2013-12-25
    Type: Structure summary
  • Version 1.3: 2017-10-25
    Type: Refinement description