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Extension of resolution and oligomerization-state studies of 2,4′-dihydroxyacetophenone dioxygenase from

DOI: 10.1107/S2053230X15015873 DOI Help
PMID: 26457516 PMID Help

Authors: J. Guo (University College London (UCL)) , P. Erskine (Royal Free and University College Medical School) , A. R. Coker (University College Medical School, UCL Divisision of Medicine) , J. Gor (University College London (UCL)) , S. J. Perkins (University College London (UCL)) , S. P. Wood (University College London (UCL)) , J. B. Cooper (University College London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Acta Crystallographica Section F Structural Biology Communications , VOL 71 , PAGES 1258 - 1263

State: Published (Approved)
Published: October 2015
Diamond Proposal Number(s): 8922

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).

Journal Keywords: 2; 4'-Dihydroxyacetophenone Dioxygenase; Protein X-Ray Structure; Oligomerization; Analytical Ultracentrifugation; Gel Filtration; Docking; Dioxygenase.

Diamond Keywords: Enzymes; Bacteria

Subject Areas: Biology and Bio-materials

Instruments: I04-1-Macromolecular Crystallography (fixed wavelength)

Added On: 20/10/2015 17:29

Discipline Tags:

Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)