Figure 5.

Comparison of the thermodynamic parameters for E. coli riboswitches. A. Comparison of all ΔH terms from kinITC. The three curves are related by ΔH_ITC= ΔH_Binding+ ΔH_Folding. The pattern is similar for the two E. coli riboswitches: the two ΔH_Binding curves cross ΔH_Binding= 0 at nearby temperatures and the two ΔH_Folding curves are quasi parallel. B. Quasi absence of temperature variation for ${\displaystyle {\mathit{K}}_{\mathit{d}}.}$ Each ${\displaystyle {\mathit{K}}_{\mathit{d}}}$ curve has been normalized to a unit value at its maximum (0.93 µM for ECthiC and 0.45 µM for ECthiM). ${\displaystyle {\mathit{K}}_{\mathit{d}}}$ is almost constant for ECthiC and varies at most twofold for ECthiM in a broad temperature range in comparison of ${\displaystyle {\mathit{K}}_{\mathit{d}}(\text{overall})\mathit{ }}$ which varies tenfold for ECthiM (Fig. 4A) and more than thirtyfold for ECthiC (Fig. SD-7A).