Figure 3. Performances of selected twister-based two-input Boolean logic gates.

(a) Schematic representation of the twister-based two-input riboswitches. The communicarion modules (CM) are represented with blue boxes. The Shine-Dalgarno (SD) and the anti-SD are shown in light blue and grey respectively. (b) Level of eGFP expression (bulk fluorescence divided by the relative OD₆₀₀) and flow cytometry (FC) histograms of the positive and negative controls in the four growth conditions. (c) Level of eGFP expression (bulk fluorescence divided by the relative OD₆₀₀) and FC histograms of the Boolean logic gates AND, NAND, OR, NOR, theo_ANDNOT_TPP (ANDNOT1), TPP_ANDNOT_theo (ANDNOT2) are shown. The FC traces of (b) the controls and (c) the two-input switches were recorded in the absence of ligand (black traces −0 0), in the presence of 2.5 mM theophylline (grey traces −1 0), 1 mM thiamin (blue traces −0 1) and 2.5 mM theophylline/1 mM thiamin (green traces −1 1). The threshold values, which are represented with dashed lines, allow defining high (value 1) and low (value 0) eGFP expression. The error bars represent s.d. calculated on independent biological triplicates.