Figure 4.

NMR evidence for formation of the SLIds2/SLV complex. (A) Proposed secondary structure of SLIds2, a double-stranded SLI variant, and SLV in their free (left) and bound (right) forms. (B) Imino region of 1D ¹H NMR spectra recorded for the titration of ¹⁵N-labeled SLIds2 with unlabeled SLV. 1D NMR spectra were collected under the same conditions and plotted as described in Figure 2. Imino proton assignment is provided for both SLIds2 and SLV in their free forms. (C) Imino region of the 2D NOESY spectrum of the ¹⁵N-SLIds2/SLV complex. The signals marked with an asterisk are decoupling artifacts. On top, 1D ¹⁵N-filtered (green; SLV) and ¹⁵N-edited (purple; SLIds2) spectra of the complex annotated with imino proton assignment. Annotations in (B) and (C) are used to identify imino signals within SLIds2 (purple), SLV (green), and at the kissing-loop junction (orange), which provide evidence for the base pairs shaded with the corresponding colors in (A).