4.2.3.118 | in unliganded state and in complex with two Mg2+ ions and 2-fluoroneryl diphosphate at 1.85 and 2.00 A resolution, respectively. Cocrystallization with the fluorinated analogue of the tertiary allylic diphosphate intermediate, 2-fluorolinalyl diphosphate yields the crystal structure of the complex with the primary allylic diphosphate, 2-fluoroneryl diphosphate. The crystalline enzyme active site remains partially open, presumably due to the binding of only two Mg2+ ions |