Fig. 8.

Long-range interactions between the C-terminal tail of Rbfox2 RRM and the lower stem of pre-miR-20b detected by PRE. (A) Overlays of ¹H-¹⁵N HSQC spectra of ¹⁵N-labeled Rbfox2 RRM in complex with paramagnetic spin-labeled pre-miR-20b before (red) and after (green) reduction of the spin label introduced at position U43. Some resonances from the C-terminal tail of the Rbfox2 RRM, which are broadened by the paramagnetic spin label of pre-miR-20b, are annotated. (B) Intensity ratios of NH cross-peaks from the Rbfox2 RRM in complex with pre-miR-20b, between paramagnetic and diamagnetic forms. Residues from the β2β3 loop (around Glu152) and the C-terminal region (Val195–Val215) show significant depressions, indicating long-range contacts between the bottom part of the RNA and the protein. (C) Cartoon representation showing how the highly conserved C-terminal tail of the Rbfox2 RRM can reach the bottom part of the stem-loop to provide additional intermolecular interactions. The figure is adapted from the supplementary information in Ref. [114]. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)