Crystallization and preliminary X-ray analysis of swine vesicular disease virus (SVDV)

Three different crystal forms of the swine vesicular disease virus (SVDV), isolate SPA/2/'93, were obtained by the hanging-drop vapour-diffusion technique using ammonium sulfate and sodium/potassium phosphate as precipitants. Monoclinic crystals, space group C2, with unit-cell parameters a = 473.7, b = 385.3, c = 472.8 Å, β = 100.4°, contain one virus particle in the crystal asymmetric unit and diffract to 3.0 Å resolution. A second type of crystals had a cubic morphology and diffracted beyond 2.6 Å resolution. These crystals belong to a primitive orthorhombic space group, with unit-cell parameters a = 319.6, b = 353.8, c = 377.7 Å, and contain half a virus particle in the asymmetric unit. A third type of crystals, with a prismatic shape and belonging to space group I222, was also obtained under similar crystallization conditions. These latter crystals, with unit-cell parameters a = 318.3, b = 349.9, c = 371.7 Å, diffract to at least 3.0 Å resolution and contain 15 protomers per asymmetric unit; this requires that three perpendicular crystal twofold axes coincide with three of the viral particles' dyad axes.