Coupling of handle-region dynamics to residues in the handle region.

<p>(A) Handle-region distance distributions for ecRNH WT (top) and V98A (bottom), illustrating the predominance of the closed state in the mutant. (B) Coupled effects of mutations at positions 95 and 101 in ttRNH (top) and ttRNH dG80 (bottom). Only ttRNH dG80 G95K/R101V shows a population of the open state significantly enriched compared to wild-type ttRNH. (C) Manipulation of relative populations by coupled mutations at positions 95 and 101. For all arginine- or lysine-containing proteins other than soRNH, mutants containing G95 and R101 (brown) populate the closed state more frequently than those containing K95 and V101 (cyan), regardless of the wild-type residues at these positions. The natively N88-containing proteins, ctRNH and hsRNH, both required additional mutations to stabilize the interface between helices B and D, as detailed in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003218#pcbi.1003218.s007" target="_blank">Figure S7</a>.