Crystallization and preliminary X-ray analysis of CTP:phosphoethanolamine cytidylyltransferase (ECT) from Saccharomyces cerevisiae

CTP:phosphoethanolamine cytidylyltransferase (ECT) is the enzyme that catalyzes the conversion of phosphoethanolamine to CDP-ethanolamine in the phosphatidylethanolamine-biosynthetic pathway (Kennedy pathway). ECT from Saccharomyces cerevisiae was crystallized by the sitting-drop vapour-diffusion method using PEG 4000 as precipitant. The crystals diffracted X-­rays from a synchrotron-radiation source to 1.88 Å resolution. The space group was assigned as primitive tetragonal, P4₁2₁2 or P4₃2₁2, with unit-cell parameters a = b = 66.3, c = 150.8 Å. The crystals contain one ECT molecule in the asymmetric unit (V_M = 2.2 Å³ Da^-1), with a solvent content of 43%.