Fig. 3: Single-molecule helicase-catalyzed unwinding experiments of the ZTP riboswitch.

a The EFRET histograms of the WT heteroduplex before and after ATP addition at different ZMP concentrations using VF with Rep-X. Gaussian fitting with global constraints was used to determine the relative populations of the initial heteroduplex (blue), terminator (green), and ZMP-bound aptamer (magenta) conformations. b Bulk single-round transcription termination experiments of ZTP riboswitch are shown in the presence of 0.2 mM NTPs and varying amounts of ZMP (0–4 mM). RT and T stand for the readthrough and terminated products, respectively. Quantification of all experiments under these conditions is shown below (mean ± standard deviation (s.d.) shown as large open circles, n = 6 independent experiments shown as small circles).