Crystallization and preliminary X-ray analysis of shikimate dehydrogenase from Escherichia coli

Shikimate dehydrogenase from Escherichia coli has been crystallized by the vapour-diffusion method using ammonium sulfate as a precipitant. Mass spectrometry confirmed the purity of the enzyme and dynamic light scattering was used to find the appropriate additives to yield a monodisperse enzyme solution. The crystals are monoclinic, space group C2, with unit-cell parameters a = 110.0, b = 139.8, c = 102.6 A, beta = 122.2 degrees (at 100 K). Native crystals diffract to 2.3 A in-house on a rotating-anode X-ray source. The asymmetric unit is likely to contain four molecules, related by 222 symmetry, corresponding to a packing density of 2.86 A(3) Da(-1).