Crystallization and preliminary X‐ray analysis of a thiol‐activated cytolysin

Abstract
We present the first reported crystallization of a member of the thiol-activated family of protein toxins. Perfringolysin O, a virulence factor of Clostridium perfringens , has been crystallized in two different forms by the hanging drop vapor diffusion method. In one form the toxin crystallizes with PEG 20000 in the orthorhombic space group C222 1 with cell dimensions of a = 47.8 A ̊ , b = 182.0 A ̊ and c = 175.5 A ̊ and the crystals diffract to beyond 2.5 Å resolution. In the second form the toxin crystallizes in a large variety of organic solvents including malt whisky. This crystal form belongs to the orthorhombic space group P222 1 with unit cell dimensions a = 47.1 A ̊ , b = 166.1 A ̊ and c = 214.0 A ̊ and with diffraction observed to 2.4 Å resolution.