Mss116p did not alter RNA folding nonspecifically. (A) HP210-510 has the potential to adopt a functional structure with an H1 helix that has a calculated free energy of −17.2 kcal/mol (72.0 kJ/mol) or a nonfunctional structure with a 5′AltH1 that has a calculated free energy of −20.2 kcal/mol (84.5 kJ/mol). Chimeric mRNAs with HP210-510 were coexpressed in yeast with (B) active Mss116p (Δmts), (C) catalytically inactive Mss116p (ΔmtsE268Q), or (D) empty vector. Mss116p expression had no detectable effect on HP210-510 self-cleavage activity. Plots display results from a representative pair of experiments with functional (▪) and mutationally inactivated (□) chimeric HP210-510 mRNAs. Reported values represent the mean and standard deviation obtained from two or more pairs of experiments.
