Crystallization at low salt concentration and alkaline pH and preliminary crystallographic data for a monoclinic form of yeast enolase

Yeast enolase (2-phospho-D-glycerate hydrolyase, E.C. 4.2.1.11) has been crystallized by vapor diffusion from a solution containing 22% PEG 4000, 100 mM Tris buffer pH = 9.3, 200 mM Li₂SO₄. The crystals are monoclinic with a = 122.5, b = 111.8, c = 63.7 A, β = 95.6°, space group P2₁ and two dimeric molecules are present in an asymmetric part of the unit cell. Crystals have been successfully transferred to an artificial mother liquor, pH = 7.8, 20 mM in Mg²⁺ and 5 mM in 2-phospho-D-glycerate. We believe that under these lower salt concentration and more alkaline conditions we should be able to localize the two metal ions that participate in catalysis as well as examine binding of high-affinity inhibitors.