the gene for this enzyme results from a single base change n410 a -- -- t in the gene of pbr322 rtem beta-lactamase ( ec 3.5.2.6 , penicillinase , penicillin amido-beta-lactamhydrolase ) which alters the codon for the active site ser 70 to that for cys .
C1333402
gene
C0023689
ec