Figure 2
From: A method for selecting cis-acting regulatory sequences that respond to small molecule effectors
The effects of amino acid substitutions in the E4 sequence. Amino acid substitutions in mutants are marked in capital letters. All sequence variants were tested as β-galactosidase fusions. The expression of β-galactosidase marker protein was measured 3 h after induction with IPTG in the absence and presence of the corresponding antibiotic. The activity of each construct is shown as a ratio of Miller units measured in the absence and presence of antibiotic.