Figure 3.

B–Z transition induced by the DNA bending force with different salt MgCl₂. (a) FRET histograms of B–Z linear and BZ29-S19 samples at various concentrations of MgCl₂ obtained by the ALEX method. Histograms were fitted to a single Gaussian distribution. The black dotted lines denote the E of each sample in the absence of MgCl₂. The red dotted lines denote the E of each sample at 1500 mM MgCl₂. (b) E of B–Z linear and D-shaped DNA samples (BZ29-S27 and BZ29-S19) plotted against the concentration of MgCl₂. The dotted lines denote the midpoint of each sample. Error bars were obtained from three independent measurements. (c) B–Z transition midpoint of each sample (B–Z linear, BZ29-S27, and BZ29-S19). The midpoints decrease as the bending force increases, which shows the same trend as in Figure 2f. Error bars were obtained from three independent measurements.