Construction and overexpression in Escherichia coli of genetically engineered derivatives of penicillin‐binding protein 2′ of Staphylococcus epidermidis

Removal of the putative amino‐terminal membrane spinning region of penicillin‐binding protein 2′ (PBP‐2′) of Staphylococcus epidermidis WT55 was carried out by truncating the amino terminus‐coding end of the mecA gene, PCR and site directed mutagenesis were used to introduce unique restriction sites at position 68 (HindIII) and at position 80 (NcoI) of the mecA gene, respectively. The coupling of the shortened coding regions to the trc promoter and gene fusion to the lacZ gene, aimed to facilitate subsequent protein purifications, resulted in strong expression in the cytoplasm of Escherichia coli and partial sequestration into insoluble protein granules. The truncated PBP‐2′ retained its penicillin‐binding ability and also bound the monoclonal antibody directed against PBP‐2′ of Staphylococcis aureus.