1.1.1.23	C112A	conserved Cys-112 is not involved in catalysis, Cys-112 corresponds to Cys-116 in Salmonella typhimurium	
1.1.1.23	C366S	site-directed mutagenesis	
1.1.1.23	C366S	mutant enzyme crystal structure analysis	
1.1.1.23	H261N	mutation causes complete loss of Zn and activity	
1.1.1.23	additional information	site-directed mutagenesis of hisD, resulting in the replacement of the five His-residues with asparagine or glutamine, causes an important decrease in kcat for His261 and His326