Changes in the periplasmic linker and in the expression level affect the activity of ToxR and λ‐ToxR fusion proteins in Escherichia coli

Abstract

In order to assess the potentiality of Vibrio cholerae ToxR protein and of bacteriophage V V repressor as indicators of the dimerization of periplasmic proteins in Escherichia coli, we have constructed a series of plasmids encoding transmembrane fusion proteins. The amino-terminal part, containing the DNA binding domain of either ToxR or V V repressor, is located in the cytoplasm and acts as reporter for dimerization. As models of periplasmic proteins we have used alkaline phosphatase (a dimer) and L L-lactamase (a monomer). Both the expression level and the distance between the transmembrane segment and the periplasmic protein substantially affect the activity of the reporter domains.z 1998 Federation of European Biochemical Societies.

Screening Peptide/Protein Libraries Fused to the λ Repressor DNA-Binding Domain in E. coli Cells

“…7. Similar plasmids have been constructed by other groups (5,(8)(9)(10) with a variety of modifications. In all cases, unique restriction sites are available for cloning a desired insert in-frame with the N-terminal domain of repressor.…”