FIGURE 3.

A, single-round in vitro transcriptions performed for wild-type (WT), G39-C65 base pair, and G39U-C65 riboswitch variants. Reactions were carried out in the absence (−) of ligand and in the presence of 10 μm 2,6-diaminopurine (DAP; +). Two portions of the same gel, separated by a black line, were juxtaposed for better comparison. Readthrough (RT) and terminated (T) products are indicated on the right. Percentages of readthrough (% RT) products are indicated below the gel. B, β-galactosidase assays of the WT, G39-C65 base pair, and G39U-C65 constructs. Enzymatic activities were assayed in B. subtilis grown in minimal medium in the absence or presence of the indicated ligands (0.5 mg/ml) after an incubation of 3 h. Each experiment was performed three times, and the average as well as the S.D. are shown. C, β-galactosidase assays of the wild type and selected riboswitch mutants. The assays were performed in the absence or presence of the indicated ligands. D, β-galactosidase assays of the G39-C65 variant (−−) and selected mutants in the context of the G39-C65 riboswitch. The assays were performed in the absence or presence of the indicated ligands.