Figure 5.

Measuring RNAP interaction with double-stranded promoter fragments using RNAP beacon assay. Normalized beacon signal amplitudes were measured in samples containing 1 nM Taq Eσ^A (dark bars) or Ec Eσ⁷⁰ (light bars) beacons and probes truncated at the indicated positions; the probe concentrations and temperatures were 4 nM, 45°C and 2 nM, 25°C in the experiments with Taq Eσ^A and Ec Eσ⁷⁰, respectively. The experimental variation of F/F_max among replicate measurements did not exceed 20% of the average value.