Figure 3.

NMR of RNA binding. (A) Spectra of 50 μM ¹⁵N-labeled LARP1 (323-410) alone (black) and in the presence of 100 μM A₂ (red). Shifts of selected signals are labeled. Side chains resonances are labeled sc. Signal assignments are shown in Supplementary Figure S5. (B) Spectra of 50 μM ¹⁵N-labeled LARP1 (323–410) alone (black) and in the presence of 50 μM A₆ (red). (C) Comparison of peak shifts showing fast-exchange in the A₂ spectra and slow-exchange in the A₆ spectra. The slower dynamics of A₆ binding is consistent with higher affinity of A₆. (D) Plot of LaM amide proton and nitrogen chemical shifts changes upon A₆ binding. Supplementary Figure S6A shows the shifts mapped onto the 3D structure.