Supplementary Figure 2: SUP-12 RRM efficiently binds to 5′-GUGUGC-3′.
From: RBFOX and SUP-12 sandwich a G base to cooperatively regulate tissue-specific splicing
(a) The 1H-15N HSQC spectrum of SUP-12 RRM, showing the amide chemical shift changes in the absence (black) and presence (ratio of SUP-12 RRM: RNA=1:2, red) of RNA6. Assignments are shown in the 3-letter amino acid code with the position numbers. (b) Quantification of the chemical-shift perturbation values of SUP-12 RRM upon binding to RNA6 (ratio of protein:RNA=1:2). The perturbation values greater than the baseline plus three times the standard deviation of the baseline (3 x 0.08 ppm) were considered as significant perturbations (i.e., the significant level is 0.34 ppm, indicated by a dashed red line). Black letters indicate amino acid residues with significant chemical shift changes. (c,d) Solution structures of the SUP-12–RNA6 complex. (c) A stereo view of the backbone traces of the 20 conformers of the complex. The backbone of SUP-12 RRM is colored magenta. The RNA molecule is green.
(d) Ribbon and stick representations of the complex. Upper panel, a stereo view; lower panel, another view of the complex rotated by 45° as indicated. The side chains of SUP-12 RRM involved in the RNA-recognition are represented as follows: green, carbons; red, oxygen; blue, nitrogen. The RNA is represented by a ball-and-stick model, where carbon, oxygen, nitrogen and phosphorus atoms are colored dark gray, red, blue and yellow, respectively.
