3.8.1.8	purified recombinant detagged wildtype and mutant enzymes, mixing of 11.6 mg/ml protein in 50 mM HEPES, pH 7.5, and 100 mM NaCl with a reservoir solution containing 5.5% w/v PEG 8000, 2.7% v/v diethylene glycol, 50 mM HEPES, pH 7.1 or 50 mM HEPES pH 7.3, 4.6% w/v PEG 10 000, at 8°C, resulting in two different crystal forms, X-ray diffraction structure determination and analysis at 2.8 A and 2.2 A resolution, respectively, modeling	
3.8.1.8	purified recombinant Zn2+-bound wild-type TrzN, and zinc-bound TrzN mutant E241Q complexed with ametryn or atratone, hanging drop method, for the wild-typeenzyme: 21 mg/ml TrzN in 25 mM MOPS, pH 5.5, and 1mM ZnCl2 with precipitant solution containing 25% PEG 3350, 0.1 M Bis-Tris, pH 5.5, 0.2 M ammonium sulfate, and 1 mM ZnCl2, 7-8 days at 25°C. For the mutant enzyme: 6.6 mg/ml TrzN-E241Q in 25 mM MOPS, pH 5.5, and 1 mM ZnCl2 with precipitant containing 30% PEG 4000, 0.1 M sodium citrate, pH 5.6, 0.2 M ammonium acetate, and 1 mM ZnCl2, 2 weeks at 25°C, soaking of crystals for 1 h in cryobuffer composed of its mother liquid, 15% glycerol, and excess of the ametryn or atratone powder, X-ray diffraction structure determination and analysis at 1.40 A, 1.93 A, and 1.64 A resolutions, respectively, modeling