Figure 1.

Crystallization of rHetR. (A) SDS/PAGE of purified rHetR under reducing (lane 1) and nonreducing (lane 2) conditions. The purified rHetR was in TS (see text) buffer containing EGTA (1 mM) after the final step of purification. The molecular mass standards (in kilodaltons) are shown on the left. (B) Photographs of rHetR crystals. Conditions for crystal formation with NaCl as precipitant are described in Materials and Methods. The crystals are mounted on a slide in polyethylene glycol 6000 solution and photographed through a Leica microscope. The average sizes of large crystals are 0.5 × 0.5 × 0.25 mm. (Bars = 0.5 mm.)