3rja
From Proteopedia
Crystal structure of carbohydrate oxidase from Microdochium nivale in complex with substrate analogue
Structural highlights
FunctionMNCO_MICNN Catalyzes the selective oxidation of C1 hydroxyl moieties on mono-, oligo- and polysaccharides with concomitant reduction of molecular oxygen to hydrogen peroxide. This results in the formation of the corresponding lactones, which typically undergo spontaneous hydrolysis. Carbohydrate oxidase is able to oxidize a variety of substrates including D-glucose, D-galactose, D-xylose, D-maltose, D-cellobiose, and lactose. In addition, among various oligosaccharides, the enzyme preferred tetrameric dextrins, indicating a favorable interaction of four linked glucose units with the substrate binding pocket.[1] [PROSITE-ProRule:PRU00718][2] Publication Abstract from PubMedMicrodochium nivale carbohydrate oxidase was produced by heterologous recombinant expression in Aspergillus oryzae, purified and crystallized. The enzyme crystallizes with varying crystal morphologies depending on the crystallization conditions. Several different crystal forms were obtained using the hanging-drop vapour-diffusion method, two of which were used for diffraction measurements. Hexagon-shaped crystals (form I) diffracted to 2.66 A resolution, with unit-cell parameters a = b = 55.7, c = 610.4 A and apparent space group P6(2)22. Analysis of the data quality showed almost perfect twinning of the crystals. Attempts to solve the structure by molecular replacement did not give satisfactory results. Recently, clusters of rod-shaped crystals (form II) were grown in a solution containing PEG MME 550. These crystals belonged to the monoclinic system C2, with unit-cell parameters a = 132.9, b = 56.6, c = 86.5 A, beta = 95.7 degrees . Data sets were collected to a resolution of 2.4 A. The structure was solved by the molecular-replacement method. Model refinement is currently in progress. Crystallization of carbohydrate oxidase from Microdochium nivale.,Duskova J, Dohnalek J, Skalova T, Ostergaard LH, Fuglsang CC, Kolenko P, Stepankova A, Hasek J Acta Crystallogr Sect F Struct Biol Cryst Commun. 2009 Jun 1;65(Pt 6):638-40., Epub 2009 May 23. PMID:019478452[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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