5A4K

Crystal structure of the R139W variant of human NAD(P)H:quinone oxidoreductase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.09 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.169 
  • R-Value Observed: 0.171 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

Catalytic competence, structure and stability of the cancer-associated R139W variant of the human NAD(P)H:quinone oxidoreductase 1 (NQO1).

Lienhart, W.D.Strandback, E.Gudipati, V.Koch, K.Binter, A.Uhl, M.K.Rantasa, D.M.Bourgeois, B.Madl, T.Zangger, K.Gruber, K.Macheroux, P.

(2017) FEBS J 284: 1233-1245

  • DOI: https://doi.org/10.1111/febs.14051
  • Primary Citation of Related Structures:  
    5A4K

  • PubMed Abstract: 

    The human NAD(P)H:quinone oxidoreductase 1 (NQO1; EC1.6.99.2) is an essential enzyme in the antioxidant defence system. Furthermore, NQO1 protects tumour suppressors like p53, p33 ING 1b and p73 from proteasomal degradation. The activity of NQO1 is also exploited in chemotherapy for the activation of quinone-based treatments. Various single nucleotide polymorphisms are known, such as NQO1*2 and NQO1*3 yielding protein variants of NQO1 with single amino acid replacements, i.e. P187S and R139W, respectively. While the former NOQ1 variant is linked to a higher risk for specific kinds of cancer, the role, if any, of the arginine 139 to tryptophan exchange in disease development remains obscure. On the other hand, mitomycin C-resistant human colon cancer cells were shown to harbour the NQO1*3 variant resulting in substantially reduced enzymatic activity. However, the molecular cause for this decrease remains unclear. In order to resolve this issue, recombinant NQO1 R139W has been characterized biochemically and structurally. In this report, we show by X-ray crystallography and 2D-NMR spectroscopy that this variant adopts the same structure both in the crystal as well as in solution. Furthermore, the kinetic parameters obtained for the variant are similar to those reported for the wild-type protein. Similarly, thermostability of the variant was only slightly affected by the amino acid replacement. Therefore, we conclude that the previously reported effects in human cancer cells cannot be attributed to protein stability or enzyme activity. Instead, it appears that loss of exon 4 during maturation of a large fraction of pre-mRNA is the major reason of the observed lack of enzyme activity and hence reduced activation of quinone-based chemotherapeutics.


  • Organizational Affiliation

    Institute of Biochemistry, Graz University of Technology, Austria.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
NAD(P)H DEHYDROGENASE [QUINONE] 1
A, B, C, D
294Homo sapiensMutation(s): 1 
EC: 1.6.5.2
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
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.09 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.169 
  • R-Value Observed: 0.171 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 54.606α = 100.37
b = 56.928β = 92.85
c = 99.827γ = 90.22
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling
PHASERphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2016-06-29
    Type: Initial release
  • Version 1.1: 2017-03-08
    Changes: Database references
  • Version 1.2: 2017-04-26
    Changes: Database references
  • Version 1.3: 2024-01-10
    Changes: Data collection, Database references, Derived calculations, Other, Refinement description