Two-dimensional Crystallization-- Purified protein (2 mg/ml) was mixed 
  with E. coli lipids solubilized in OTG (mixed micelles stock solution, 
  4 mg/ml E. coli lipids in 20 mM Mes-NaOH (pH 6), 5% OTG, 0.01% NaN3) 
  to achieve a lipid to protein ratio of 1 (w/w). The final protein 
  concentration was adjusted to 1.33 mg/ml, and the final OTG content 
  was adjusted to 1.93%. The reconstitution mixture (60 microliters) 
  was preincubated at room temperature for 30 min and dialyzed against 
  1.5 liters of 10 mM Mes-NaOH (pH 6), 100 mM NaCl, 100 mM MgCl2, 
  2 mM dithiothreitol, 0.01% NaN3 for 24 h at room temperature, 
  24 h at 37 C, and another 24 h at room temperature.