2QR2

HUMAN QUINONE REDUCTASE TYPE 2, COMPLEX WITH MENADIONE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.45 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.218 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of human quinone reductase type 2, a metalloflavoprotein.

Foster, C.E.Bianchet, M.A.Talalay, P.Zhao, Q.Amzel, L.M.

(1999) Biochemistry 38: 9881-9886

  • DOI: 10.1021/bi990799v
  • Primary Citation of Related Structures:  1QR2
  • Also Cited By: 1DXO, 1DXQ, 1H66, 1H69

  • PubMed Abstract: 
  • In mammals, two separate but homologous cytosolic quinone reductases have been identified: NAD(P)H:quinone oxidoreductase type 1 (QR1) (EC 1.6.99.2) and quinone reductase type 2 (QR2). Although QR1 and QR2 are nearly 50% identical in protein sequence ...

    In mammals, two separate but homologous cytosolic quinone reductases have been identified: NAD(P)H:quinone oxidoreductase type 1 (QR1) (EC 1.6.99.2) and quinone reductase type 2 (QR2). Although QR1 and QR2 are nearly 50% identical in protein sequence, they display markedly different catalytic properties and substrate specificities. We report here two crystal structures of QR2: in its native form and bound to menadione (vitamin K(3)), a physiological substrate. Phases were obtained by molecular replacement, using our previously determined rat QR1 structure as the search model. QR2 shares the overall fold of the major catalytic domain of QR1, but lacks the smaller C-terminal domain. The FAD binding sites of QR1 and QR2 are very similar, but their hydride donor binding sites are considerably different. Unexpectedly, we found that QR2 contains a specific metal binding site, which is not present in QR1. Two histidine nitrogens, one cysteine thiol, and a main chain carbonyl group are involved in metal coordination. The metal binding site is solvent-accessible, and is separated from the FAD cofactor by a distance of about 13 A.


    Related Citations: 
    • Unexpected Genetic and Structural Relationships of a Long-Forgotten Flavoenzyme to Nad(P)H:Quinone Reductase (Dt-Diaphorase)
      Zhao, Q.,Yang, X.L.,Holtzclaw, W.D.,Talalay, P.
      (1997) Proc.Natl.Acad.Sci.USA 94: 1669


    Organizational Affiliation

    Department of Biophysics, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (QUINONE REDUCTASE TYPE 2)
A, B
230Homo sapiensGene Names: NQO2 (NMOR2)
EC: 1.10.5.1
Find proteins for P16083 (Homo sapiens)
Go to Gene View: NQO2
Go to UniProtKB:  P16083
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
VK3
Query on VK3

Download SDF File 
Download CCD File 
B
MENADIONE
VITAMIN K3; 2-METHYL-1,4-NAPHTHALENEDIONE
C11 H8 O2
MJVAVZPDRWSRRC-UHFFFAOYSA-N
 Ligand Interaction
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
FAD
Query on FAD

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.45 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.218 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 83.600α = 90.00
b = 106.270β = 90.00
c = 56.080γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-08-18
    Type: Initial release
  • Version 1.1: 2007-10-16
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance