Construction and characterization of pyocin-colicin chimeric proteins.

Chimeric proteins were constructed from pyocin S1 or S2 and colicin E3 or E2, and their characteristics were investigated with special reference to the domain structure. The nuclease domains were interchangeable between two bacteriocins so that a new kind of pyocin, with RNase activity, was created. A bacteriocin which can kill both Pseudomonas aeruginosa and Escherichia coli was also constructed. Investigations with various chimeric proteins indicate that the translocation domain as well as the receptor-binding domain is species specific. Inhibition of lipid synthesis, which is characteristic of pyocins, was also observed with chimeric pyocins carrying the DNase domain of colicin E2 but not with those carrying the RNase domain of E3. Thus, the DNase domain is responsible for the inhibition of lipid synthesis.