Changes in the periplasmic linker and in the expression level affect the activity of ToxR and lambda-ToxR fusion proteins in Escherichia coli.
In order to assess the potentiality of Vibrio cholerae ToxR protein and of bacteriophage lambda 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 lambda 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 beta-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.
Jappelli
R
R
The Molecular Sciences Institute, Berkeley, CA 94704, USA. rjappelli@molsci.com
Brenner
S
S
D000469:Alkaline Phosphatase / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D019281:Dimerization; D004926:Escherichia coli / Q000737:chemistry*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D017930:Genes, Reporter / Q000235:genetics; D008565:Membrane Proteins / Q000378:metabolism; D019897:Periplasm / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014734:Vibrio cholerae / Q000737:chemistry; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; D001618:beta-Lactamases / Q000378:metabolism
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins; C066719:toxR protein, bacteria; D000469:Alkaline Phosphatase; D001618:beta-Lactamases