Expression and crystallization of the yeast Hsp82 chaperone, and preliminary X-ray diffraction studies of the amino-terminal domain.

Abstract

Expression of the Saccharomyces cerevisiae Hsp82 chaperone in a pep4-3- and hsc82-deficient strain of S. cerevisiae yielded over 25% of the total cell protein as intact Hsp82. Similarly, the amino-terminal domain (residues 1-220) of Hsp82 was expressed to 18% of the total cell protein. Crystals of the intact Hsp82 were readily obtained. The crystals were very fragile, suggesting a high solvent content, and diffracted to approximately 8 A. Tetragonal bipyrimidal crystals of the amino-terminal domain of Hsp82 were readily obtained under a variety of different conditions. The crystals have primitive tetragonal space group (P422, P4(1)22, or its enantiomorph P4(3)22) with unit cell dimensions of a = 75.1 A and c = 111.3 A, contain 60% by volume solvent, and diffract to 2.5 A resoltuion. Addition of 25% glycerol to the mother liquor gave rise to large rod-shaped crystals. The crystals diffract to 2.8 A resolution, have an orthorhombic space group (P222(1), P2(1)2(1)2, or P2(1)2(1)2(1)) with cell dimensions of a = 45.2 A, b = 115.4 A, and c = 116.9 A, and a solvent content of 58% by volume.