Figure 1.

The studied RRM protein/RNA complexes: (A) Fox-1 complex. The non-canonical (hydrophobic pocket) and canonical parts of the protein/RNA interface are highlighted in red and blue respectively; (B) SRSF1 complex. The protein/RNA interface is highlighted in red. Other parts of the RNA molecule do not form specific interactions with the protein; the secondary structure of the proteins is labeled and highlighted in purple (α-helices), yellow (β-sheets) and cyan/white (loops). The RNA backbone is traced in brown. The nucleotides are numbered and the chain termini labeled. For additional structural details see Supplementary Figures S1 and S2.