CRYSTALLIZATION AND PRELIMINARY-X-RAY DIFFRACTION ANALYSIS OF ASPARTATE-AMINOTRANSFERASE FROM SACCHAROMYCES-CEREVISIAE

Diffraction-quality crystals of S. cerevisiae cytoplasmic aspartate am inotransferase have been obtained by the hanging-drop vapor-diffusion method in the presence of pyridoxal phosphate and maleic acid, sodium acetate, ammonium acetate and polyethylene glycol. The crystals have t he symmetry of the orthorhombic space groups P2(1)2(1)2(1) or P2(1)2(1 )2 with unit-cell dimensions a = 130.2, b = 134.6 and c = 98.7 Angstro m. Square rod-shaped crystals.with dimensions of approximately 0.2 x 0 .2 x 0.5 mm diffract to spacings of 2 Angstrom. The calculated value o f the Matthews coefficient, V-m = 2.4 Angstrom(3) Da(-1), is consisten t with four subunits of aspartate aminotransferase per asymmetric unit .