title: Crystallization of and X-ray investigations on glucose dehydrogenase from Bacillus megaterium.
abstract: The tetrameric glucose dehydrogenase from Bacillus megaterium M1286 belongs to the 'short' family of dehydrogenases with 262 amino acids per subunit (Mr approximately 30,000), and does not require Zn2+ for enzymatic action. It was crystallized as complex with its coenzyme NAD from a 1-2% protein solution by the batch method using ammonium sulfate as precipitant at pH 6.5. Crystals appeared within two days as clusters of large plates with maximum dimensions of 2 mm, which diffract X-rays to a resolution of at least 0.2 nm. The space group is orthorhombic P2(1)2(1)2(1), unit-cell dimensions are a = 15.03 nm, b = 10.42 nm and c = 6.74 nm. Assuming one molecule (approximately 120 kDa) per asymmetric unit the VM value is 0.0022 nm3/Da and the solvent content of the crystals is 45% based on a partial specific volume for the protein of 0.723 ml/g. The crystallization was further improved by using the microdialysis technique where instead of clusters, single crystals appeared within 7 days.
mesh_terms: D001410:Bacillus megaterium / Q000201:enzymology*; D002237:Carbohydrate Dehydrogenases; D003460:Crystallization; D042843:Glucose 1-Dehydrogenase; D005948:Glucose Dehydrogenases; D008970:Molecular Weight; D009243:NAD; D014961:X-Ray Diffraction; D015032:Zinc
chemical_list: D009243:NAD; D002237:Carbohydrate Dehydrogenases; D005948:Glucose Dehydrogenases; D042843:Glucose 1-Dehydrogenase; D015032:Zinc