Extended Data Fig. 3: Exchange parameters for the A•G mismatch measured using R_1ρ in hpGAC at 10 °C.

Shown are the off-resonance ¹³C R_1ρ profiles measured for A-C1ʹ, A-C8, A-C2, and G-C8 collected at 10 °C and pH 7.4 in NMR buffer as described in Methods. Spin-lock powers used for R_1ρ profiles are color-coded. Solid lines in the profiles denote the global 2-state fits to the data using B-M equations as described in Methods. Data for the R_1ρ profiles were presented as values ± 1 s.d. from Monte Carlo simulations for one measurement as described in Methods. For the R_1ρ profiles corresponding to A-C1ʹ and A-C8, the ± 1 s.d. is smaller than the data points. These exchange measurements at 10 °C only sense A_syn-G_anti exchange (top) since A_anti⁺-G_syn exchange becomes too slow to have a substantial contribution (middle). Probes that sensed exchange at this condition are highlighted in green.