1QRD

QUINONE REDUCTASE/FAD/CIBACRON BLUE/DUROQUINONE COMPLEX


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Work: 0.188 
  • R-Value Observed: 0.188 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

The three-dimensional structure of NAD(P)H:quinone reductase, a flavoprotein involved in cancer chemoprotection and chemotherapy: mechanism of the two-electron reduction.

Li, R.Bianchet, M.A.Talalay, P.Amzel, L.M.

(1995) Proc Natl Acad Sci U S A 92: 8846-8850

  • DOI: https://doi.org/10.1073/pnas.92.19.8846
  • Primary Citation of Related Structures:  
    1QRD

  • PubMed Abstract: 

    Quinone reductase [NAD(P)H:(quinone acceptor) oxidoreductase, EC 1.6.99.2], also called DT diaphorase, is a homodimeric FAD-containing enzyme that catalyzes obligatory NAD(P)H-dependent two-electron reductions of quinones and protects cells against the toxic and neoplastic effects of free radicals and reactive oxygen species arising from one-electron reductions. These two-electron reductions participate in the reductive bioactivation of cancer chemotherapeutic agents such as mitomycin C in tumor cells. Thus, surprisingly, the same enzymatic reaction that protects normal cells activates cytotoxic drugs used in cancer chemotherapy. The 2.1-A crystal structure of rat liver quinone reductase reveals that the folding of a portion of each monomer is similar to that of flavodoxin, a bacterial FMN-containing protein. Two additional portions of the polypeptide chains are involved in dimerization and in formation of the two identical catalytic sites to which both monomers contribute. The crystallographic structures of two FAD-containing enzyme complexes (one containing NADP+, the other containing duroquinone) suggest that direct hydride transfers from NAD(P)H to FAD and from FADH2 to the quinone [which occupies the site vacated by NAD(P)H] provide a simple rationale for the obligatory two-electron reductions involving a ping-pong mechanism.


  • Organizational Affiliation

    Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
QUINONE-REDUCTASE
A, B
273Rattus rattusMutation(s): 0 
EC: 1.6.99.2
UniProt
Find proteins for P05982 (Rattus norvegicus)
Explore P05982 
Go to UniProtKB:  P05982
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP05982
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Work: 0.188 
  • R-Value Observed: 0.188 
  • Space Group: I 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 72α = 90
b = 107β = 92.6
c = 88.4γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
XDSdata reduction
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1996-10-14
    Type: Initial release
  • Version 1.1: 2008-03-03
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2024-02-14
    Changes: Data collection, Database references, Derived calculations, Other