FIGURE 2.

Gel electrophoresis analysis of 3′X domain molecules as a function of ionic strength. (A) Representative native gels comparing the electrophoretic mobility of wild-type and U₃C, U₅₅C, U₃C/U₅₅C, U₃G, G₅₀C/C₅₂G, and U₃G/G₅₀C/C₅₂G mutant domain molecules, previously folded in the absence or presence of 100 mM NaCl. The arrows indicate the position of the monomer (98) and homodimer (98₂) species. (B) Quantification of the homodimerization yield at 100 mM NaCl of mutant molecules relative to the wild-type domain, which was assigned a value of 1. The bars represent the average and standard deviation of three independent experiments. Mutants experimentally verified to adopt the wild-type two-stem conformation are represented in green, whereas mutants adopting a different structure are indicated in red. Conditions: 10–40 µM RNA, TB running buffer.