9FL2
Crystal structure of Oscillatoria princeps pyranose oxidase
Summary for 9FL2
| Entry DOI | 10.2210/pdb9fl2/pdb |
| Descriptor | pyranose oxidase, FLAVIN-ADENINE DINUCLEOTIDE, CHLORIDE ION, ... (4 entities in total) |
| Functional Keywords | fad, oxidoreductase, covalent flavin |
| Biological source | Oscillatoria princeps RMCB-10 |
| Total number of polymer chains | 4 |
| Total formula weight | 247095.30 |
| Authors | Rozeboom, H.J.,Fraaije, M.W. (deposition date: 2024-06-04, release date: 2024-10-30, Last modification date: 2024-11-20) |
| Primary citation | Santema, L.L.,Rozeboom, H.J.,Borger, V.P.,Kaya, S.G.,Fraaije, M.W. Identification of a robust bacterial pyranose oxidase that displays an unusual pH dependence. J.Biol.Chem., 300:107885-107885, 2024 Cited by PubMed Abstract: Pyranose oxidases are valuable biocatalysts, yet only a handful of bacterial pyranose oxidases are known. These bacterial enzymes exhibit noteworthy distinctions from their extensively characterized fungal counterparts, encompassing variations in substrate specificity and structural attributes. Herein a bacterial pyranose oxidase from Oscillatoria princeps (OPOx) was biochemically characterized in detail. In contrast to the fungal pyranose oxidases, OPOx could be well expressed in Escherichia coli as soluble, fully flavinylated and active oxidase. It was found to be highly thermostable (melting temperature >90 ⁰C) and showed activity on glucose, exhibiting an exceptionally low K value (48 μM). Elucidation of its crystal structure revealed similarities with fungal pyranose oxidases, such as being a tetramer with a large central void leading to a narrow substrate access tunnel. In the active site, the FAD cofactor is covalently bound to a histidine. OPOx displays a relatively narrow pH optimum for activity with a sharp decline at relatively basic pH values which is accompanied with a drastic change in its flavin absorbance spectrum. The pH-dependent switch in flavin absorbance features and oxidase activity was shown to be fully reversible. It is hypothesized that a glutamic acid helps to stabilize the protonated form of the histidine that is tethered to the FAD. OPOx presents itself as a valuable biocatalyst as it is highly robust, well-expressed in E. coli, shows low K values for monosaccharides and has a peculiar pH dependent "on-off switch". PubMed: 39395808DOI: 10.1016/j.jbc.2024.107885 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.64 Å) |
Structure validation
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