3.3.2.13	A244G	site-directed mutagenesis	753274	
3.3.2.13	E338A	inactive	725723	
3.3.2.13	E338Q	inactive	725723	
3.3.2.13	F226A	the mutant shows 2.5% activity compared to the wild type enzyme	725723	
3.3.2.13	R228A	the mutant shows 224.5% activity compared to the wild type enzyme	725723	
3.3.2.13	V209Q	site-directed mutagenesis	753274	
3.3.2.13	Y215F	the mutant shows 12% activity compared to the wild type enzyme	725723