title: The dimeric nature of an R-factor mediated beta-lactamase.
mesh_terms: D004352:Drug Resistance, Microbial; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology*; D009154:Mutation; D010405:Penicillinase / Q000302:isolation & purification / Q000378:metabolism; D011815:R Factors; D013045:Species Specificity
chemical_list: D010405:Penicillinase