Fig. 4
RRM3 aromatic residues scalar coupling and rotamer population. a 3J NCγ and C’Cγ scalar coupling values for aromatic residues of CUG-BP2 RRM3 wild-type and Y428A mutant in the free forms and the Y428A mutant bound to 5′-UUUAA-3′. Due to the similarity in the behavior of all three mutants, only the Y428A are presented (results for the H429A and F455A mutants can be found in Supplementary Table 2 and Supplementary Fig. 7). Missing 3J values are not available due to exchange broadened resonances or overlap. b Illustration of the UP and DOWN conformations. RRM3 free (PDB ID: 2RQ4) or bound to 5′-UUUAA-3′ (this study) is in the UP conformation (Phe426 (gauche + ), Tyr428(gauche + ), His429(gauche + ), Phe455(gauche + ), Phe466(trans), Phe468(trans)). RRM3 bound to 5′-UGUGUG-3′ (PDB ID: 2RQC) is in the DOWN conformation (Phe426(trans), Tyr428(trans), His429(gauche + ), Phe455(trans), Phe466(gauche-), Phe468(gauche + )). c Aromatic residue rotamer populations at the binding interface. The pie chart shows the χ1 rotamer populations determined from the 3J NCγ and 3J C’Cγ scalar coupling constants for aromatic residues at the binding interface. The populations are not determined due to lack of 3J coupling data are colored in grey. Mutated positions are indicated by a red diamond
