CRYSTALLIZATION AND PRELIMINARY-X-RAY DIFFRACTION STUDIES OF AN A1 ALPHA-2/DNA TERNARY COMPLEX/

Crystals have been obtained of a ternary complex containing the yeast a1/alpha 2 homeodomain heterodimer bound to a al-base pair DNA site co ntaining two 5' overhanging bases at each end. The crystals are grown from cobaltic hexamine and form in space group P6(1) or P6(5) with a = b = 133 Angstrom, c = 45.4 Angstrom. Crystals that are flash-frozen a t - 179 degrees C diffract to 2.7 Angstrom along the c-axis and to 2.4 Angstrom in perpendicular directions. The crystals contain one protei n-DNA complex in the crystallographic asymmetric unit. (C) 1995 Wiley- Liss, Inc.