Partial amino acid sequence of penicillinase coded by Escherichia coli plasmid R6K

Direct studies of the amino acid sequence of an Escherichia coli plasmid-coded penicillinase (penicillin amido-beta-lactamhydrolase, EC 3.5.2.6) are in complete agreement with results derived from the translation of the DNA sequence of a related plasmid, apart from a single amino acid substitution. This penicillinase from a Gram-negative bacterium shows 30-35% identity with functionally similar enzymes from Gram-positive bacteria. This paper should be read in conjunction with the report of the DNA sequence of the gene.