5.4.3.6	mutant enzyme E71A using 100 mM trimethylamine N-oxide, 4.6 M sodium formate, at 4°C, and mutant enzyme Y63F using 95 mM trimethylamine N-oxide, 4.6 M sodium formate with 2 mM L-tyrosine, at 20°C	
5.4.3.6	refined to 2.5 A resolution. Enzyme has a closed active site well suited to retain ammonia and minimize the formation of lyase elimination products