Structure of the 2,4'-dihydroxyacetophenone dioxygenase from Alcaligenes sp. 4HAP.

Experimental Data Snapshot

  • Resolution: 1.88 Å
  • R-Value Free: 0.172 
  • R-Value Work: 0.142 
  • R-Value Observed: 0.143 

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Extension of resolution and oligomerization-state studies of 2,4'-dihydroxyacetophenone dioxygenase from Alcaligenes sp. 4HAP.

Guo, J.Erskine, P.Coker, A.R.Gor, J.Perkins, S.J.Wood, S.P.Cooper, J.B.

(2015) Acta Crystallogr F Struct Biol Commun 71: 1258-1263

  • DOI: https://doi.org/10.1107/S2053230X15015873
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The enzyme 2,4'-dihydroxyacetophenone dioxygenase (DAD) catalyses the conversion of 2,4'-dihydroxyacetophenone to 4-hydroxybenzoic acid and formic acid. This enzyme is a very unusual dioxygenase in that it cleaves a C-C bond in a substituent of the aromatic ring rather than within the ring itself. Whilst it has been shown that DAD is a tetramer in solution, the recently solved crystal structure of the Alcaligenes sp. 4HAP enzyme was in fact dimeric rather than tetrameric. Since the use of limited chymotrypsinolysis, which apparently results in removal of the first 20 or so N-terminal residues of DAD, was necessary for crystallization of the protein, it was investigated whether this was responsible for the change in its oligomerization state. Gel-filtration and analytical ultracentrifugation studies were conducted, which confirmed that chymotrypsinolysed DAD has an apparent molecular weight of around 40 kDa, corresponding to a dimer. In contrast, the native enzyme has a molecular weight in the 70-80 kDa region, as expected for the tetramer. The structural basis for tetramerization has been investigated by the use of several docking servers, and the results are remarkably consistent with the tetrameric structure of a homologous cupin protein from Ralstonia eutropha (PDB entry 3ebr).

  • Organizational Affiliation

    Department of Structural and Molecular Biology, Division of Biosciences, University College London, Darwin Building, Gower Street, London WC1E 6BT, England.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
2,4'-dihydroxyacetophenone dioxygenase153Alcaligenes sp.Mutation(s): 0 
Gene Names: dad
Find proteins for Q9REI7 (Alcaligenes sp)
Explore Q9REI7 
Go to UniProtKB:  Q9REI7
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9REI7
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.88 Å
  • R-Value Free: 0.172 
  • R-Value Work: 0.142 
  • R-Value Observed: 0.143 
  • Space Group: P 65 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 83.25α = 90
b = 83.25β = 90
c = 114.28γ = 120
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-06-10
    Type: Initial release
  • Version 1.1: 2015-06-17
    Changes: Structure summary
  • Version 1.2: 2015-10-21
    Changes: Database references