Crystallization and preliminary X-ray diffraction studies of the engrailed homeodomain and of an engrailed homeodomain/DNA complex.

The homeodomain from the engrailed protein of Drosophila has been crystallized from ammonium phosphate at pH 6.8. The crystals form in space group P6(1)22 (or P6(5)22), with cell dimensions a = b = 44.8 A and c = 118.2 A. These crystals diffract to 1.8 A resolution. A complex containing the engrailed homeodomain and a duplex DNA site also has been crystallized. The cocrystals form in space group C2 with a = 131.2 A, b = 45.5 A, c = 72.9 A and beta = 119.0 degrees. These crystals diffract to 2.6 A resolution.