1.2.1.89 structures of wild-type and mutant F34M/S405N, to 1.95 A resolution for wild-type and 2.14 and 2.10 A resolution for the mutant 739818 1.2.1.89 wild type enzyme, sitting drop vapor diffusion method, using 50 mM MOPS, 50 mM sodium HEPES pH 7.5, 20% (w/v) ethylene glycol, 10% (w/v) PEG 8000, 20 mM glutamic acid (racemic), 20 mM glycine, 20 mM serine (racemic), 20 mM alanine (racemic), 20 mM lysine-HCl (racemic). Mutant enzyme F34M/S405N, sitting drop vapor diffusion method, using 50 mM MES, 50 mM imidazole pH 6.5, 8.3% (w/v) PEG 8000, 16.7% (w/v) ethylene glycol, 20 mM sodium formate, 20 mM sodium citrate, 20 mM sodium oxamate, 20 mM ammonium acetate, 20 mM sodium potassium tartrate 762564