FIGURE 2.
A, FP of the RNA 5′-UUUAUAGUUUUU-FAM-3′ bound to a series of concentrations of mouse MSI1 RRM1. Data were fit to the Hill equation for calculation of the Kd,app. B, the change in ΔΔG due to the indicated mutation at each position of the RNA depicted in A. Mutations causing a ΔΔG of greater than 0.5 kcal/mol are shaded dark gray. C, chemical shift changes in MSI1 upon binding of two different RNA sequences: 5′-UUUAUAGUUUUU-3′ and 5′-UUUAUUUUAGUUUUU-3′. ΔδH and ΔδN are the chemical shift changes observed for the 1H and 15N resonances in the two RNA complexes, respectively. The inset shows the overlay of the 1H-15N heteronuclear single quantum coherence spectra of MSI1 bound to 5′-UUUAUAGUUUUU-3′ (red) and 5′-UUUAUUUUAGUUUUU-3′ (purple). Error bars represent the S.D. mP, millipolarization.