title: Crystallization and preliminary X-ray crystallographic analysis of alpha-amylase from Bacillus subtilis.
abstract: Large crystals of alpha-amylase from Bacillus subtilis have been obtained at room temperature using polyethylene glycol 6000 as precipitant. They grow to typical dimensions of 0.25 mm x 0.3 mm x 2.0 mm in five days. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit cell dimensions of a = 85.46 A, b = 166.5 A and c = 332.7 A. The asymmetric unit seems to contain eight molecules of alpha-amylase, with crystal volume per protein mass (Vm) of 2.69 A3/Da and solvent content of 54.3% by volume. Despite a very long c-axis, the crystals diffracted to about 2.2 A Bragg spacing using the rotating anode X-rays and were resistant to damage by X-rays. Thus they are suitable for structure determination by X-ray methods at high resolution. X-ray diffraction data have been collected to 3.4 A Bragg spacing from a native crystal.
authors.affiliation: Department of Chemistry, College of Natural Sciences, Seoul National University, Korea.
authors.forename: C
authors.initials: C
authors.lastname: Chang
authors.forename: K K
authors.initials: KK
authors.lastname: Kim
authors.forename: K Y
authors.initials: KY
authors.lastname: Hwang
authors.forename: M U
authors.initials: MU
authors.lastname: Choi
authors.forename: S W
authors.initials: SW
authors.lastname: Suh
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology*; D003460:Crystallization; D014961:X-Ray Diffraction; D000516:alpha-Amylases / Q000737:chemistry*
chemical_list: D000516:alpha-Amylases