E. coli have evolved a resistance to the tetracycline antibiotic which is found in the tetracycline operon. This operon is regulated by TetR, the tetracycline repressor, which is a dimeric protein that binds the tetracycline repressible promoter.

TetR monomer

Construct

Mutant Screening

We selected our mutants by reading GFP fluorescence in our plate reader. The green bars on the graph above indicate selections that are at least 1.5 deviations from the average wildtype fluorescence. We selected the mutants from this category with the best range of expression and further characterized them as detailed in our Data page