Crystal structure of human NAD[P]H-QUINONE oxidoreductase CO with 2,3,5,6,tetramethyl-P-benzoquinone (duroquinone) at 2.5 Angstrom resolution

Experimental Data Snapshot

  • Resolution: 2.50 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.202 

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Structures of Recombinant Mouse and Human Nad(P)H:Quinone Oxidoreductases:Species Comparison and Structural Changes with Substrate Binding and Release

Faig, M.Bianchet, M.A.Chen, S.Winski, S.Ross, D.Talalay, P.Amzel, L.M.

(2000) Proc Natl Acad Sci U S A 97: 3177

  • DOI: https://doi.org/10.1073/pnas.97.7.3177
  • Primary Citation of Related Structures:  
    1D4A, 1DXO, 1DXQ

  • PubMed Abstract: 

    NAD(P)H/quinone acceptor oxidoreductase (QR1, NQO1, formerly DT-diaphorase; EC ) protects animal cells from the deleterious and carcinogenic effects of quinones and other electrophiles. In this paper we report the apoenzyme structures of human (at 1.7-A resolution) and mouse (2.8 A) QR1 and the complex of the human enzyme with the substrate duroquinone (2.5 A) (2,3,5, 6-tetramethyl-p-benzoquinone). In addition to providing a description and rationale of the structural and catalytic differences among several species, these structures reveal the changes that accompany substrate or cofactor (NAD) binding and release. Tyrosine-128 and the loop spanning residues 232-236 close the binding site, partially occupying the space left vacant by the departing molecule (substrate or cofactor). These changes highlight the exquisite control of access to the catalytic site that is required by the ping-pong mechanism in which, after reducing the flavin, NAD(P)(+) leaves the catalytic site and allows substrate to bind at the vacated position. In the human QR1-duroquinone structure one ring carbon is significantly closer to the flavin N5, suggesting a direct hydride transfer to this atom.

  • Organizational Affiliation

    Departments of Biophysics and Biophysical Chemistry and Pharmacology and Molecular Sciences, Johns Hopkins Medical School, Baltimore, MD 21205, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B, C, D
273Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for P15559 (Homo sapiens)
Explore P15559 
Go to UniProtKB:  P15559
PHAROS:  P15559
GTEx:  ENSG00000181019 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP15559
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.50 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.202 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 55.579α = 76.24
b = 56.912β = 76.73
c = 97.755γ = 86.33
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2000-04-23
    Type: Initial release
  • Version 1.1: 2014-11-12
    Changes: Database references, Derived calculations, Non-polymer description, Other, Refinement description, Structure summary, Version format compliance
  • Version 1.2: 2017-07-05
    Changes: Data collection
  • Version 1.3: 2024-05-08
    Changes: Data collection, Database references, Derived calculations