FIGURE 2.

GAAA tetraloop–receptor complex formation analyzed by nondenaturing gel electrophoresis. Lane 1: A21U, A22G double mutant (monomeric) RNA. Lane 2: GAAA tetraloop–receptor RNA. Gels conditions: 90 mM Tris-borate (pH 7.6) and (A) 2 mM EDTA, (B) 2 mM MgCl₂, and (C) 250 mM KCl and 2 mM EDTA. The relative mobilities of lanes 1 and 2 within each panel can be compared directly, but the relative mobilities in A, B, and C cannot be directly compared due to the different electrophoretic conditions.