2.2. Crystallization  

Initial crystallization screening was performed using Crystal Screen and Crystal Screen 2 (Hampton Research) and Wizard Classic 1 & 2 (Rigaku Reagents). Crystals were obtained after 1–2 weeks of incubation at 293 K using the sitting-drop vapor-diffusion method. The drops consisted of 1 µl protein solution and 1 µl reservoir solution and were equilibrated against 70 µl reservoir solution. The best crystals were obtained from Crystal Screen 2 solution No. 14 (0.2 M sodium/potassium tartrate tetrahydrate, 0.1 M sodium citrate tribasic dihydrate, 2.0 M ammonium sulfate pH 5.6) and were used without further optimization. Crystallization information is summarized in Table 2 ▸.