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

Charaterization of individual modifications. (A) Schematic structure of the U2 stem I containing 2′-O-methylguanosines (G_m) at positions 12 and 19 (left) and corresponding FRET histogram at 40 mM Mg²⁺ (right). (B) Schematic structure of the U2 stem I containing G_m at position 19 (left) and corresponding FRET histogram at 40 mM Mg²⁺ (right). (C) Schematic structure of the U2 stem I containing G_m at position 12 (left) and corresponding FRET histogram at 40 mM Mg²⁺ (right). All modified bases are shown in purple.