Crystallization and preliminary X-ray analysis of 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase (tyrosine inhibitable) from Saccharomyces cerevisiae

3-Deoxy-D-arabino-heptulosonate-7-phosphate synthase (E.C. 4.1.2.15) catalyzes the first step in the biosynthesis of aromatic amino acids: the condensation of phophoenolpyruvate and erythrose 4-­phosphate to 3-deoxy-D-arabino-heptulosonate-7-phosphate. Diffraction-quality crystals of the tyrosine-inhibitable form of the enzyme from Saccharomyces cerevisiae have been obtained by the hanging-drop vapour-diffusion method in the presence of polyethylene glycol. The crystals belong to the triclinic space group P1, with unit-cell parameters a = 81.5, b = 94.0, c = 104.6 Å, α = 65.5, β = 85.2, γ = 75.0°, and can be flash-cooled using glycerol as a cryoprotectant. A data set to 2.3 Å has been collected at 120 K.