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-phospate synthase (E.C. 4.12.15) catalyze s the first step in the biosynthesis of aromatic amino acids: the condensat ion of phophoenolpyruvate and erythrose 4-phosphate to 3-deoxy-D-arabino-he ptulosonate-7-phosphate. Diffraction-quality crystals of the tyrosine-inhib itable 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-cel l parameters a = 81.5, b = 94.0, c = 104.6 Angstrom, alpha = 65.5, beta = 8 5.2, gamma = 75.0 degrees, and can be Bash-cooled using glycerol as a cryop rotectant. A data set to 2.3 Angstrom has been collected at 120 K.