Post-transcriptional modifications modulate conformational dynamics in human U2–U6 snRNA complex

Modified bases affect structural dynamics of the hU2–U6 complex. (A) Schematic structure of the U2 stem I containing post-transcriptionally modified bases (purple). (B) FRET trajectories of the modified U2–U6 complex exhibiting three different FRET states in 10 and 40 mM Mg²⁺. (C) FRET histograms obtained from >100 trajectories in 10 and 40 mM Mg²⁺. (D) Observed folding rate constants (k₁, k₋₁, k₂, and k₋₂) of the hU2–U6 snRNA complex with (purple) and without (green) post-transcriptionally modified bases in 40 mM Mg²⁺.