we describe a procedure by which the codon ( agc ) for the active-site serine-70 of pbr322 beta-lactamase ( penicillinase , penicillin amido-beta-lactamhydrolase , ec 3.5.2.6 ) is altered to that for cysteine ( tgc ) .
C0030841
penicillinase
C0597979
beta-lactamhydrolase