Fig. 2.

Representative FECs for the nine pseudoknots. FECs from the different pseudoknots, arranged by increasing −1 PRF efficiency of the pseudoknot from left to right, show qualitatively similar unfolding. FECs in black show unfolding from the native structure, and those in blue, from alternate structures. States were distinguished primarily by the contour length changes upon unfolding, using WLC fits (purple: native structure; brown: unfolded; green: alternate structure). (Insets) Secondary structures of the pseudoknots. Available high-resolution structures are shown in Fig. S1.