Figure 5. Tertiary structure stability landscapes of the c-di-GMP-I riboswitch in the presence of cognate and non-cognate ligand binding.

Full multiplexed experimental landscapes were replicated three times for each ligand. One replicate of each is plotted here. (a) T_m^3° landscape as a function of Mg²⁺ and c-di-GMP. Additions of Mg²⁺ or c-di-GMP both monotonically increase the T_m^3°. (b) T_m^3° landscape as a function of Mg²⁺ and kanamycin B. Addition of kanamycin B does not affect the T_m^3° at high Mg²⁺ concentrations. At low Mg²⁺ concentrations, the T_m^3° increases in the presence of kanamycin B (see also Supplementary Fig. 10 for details). The highest T_m^3° for this riboswitch was determined in the presence of the non-cognate ligand kanamycin B.