The fungal natural product azaphilone-9 binds to HuR and inhibits HuR-RNA interaction in vitro
Fig 3
NMR titrations of ILV-labeled HuR RRM1/2 with AREc-fos.
(A) Overlay of five 2D 1H-13C HSQC spectra of ILV-labeled HuR RRM1/2 titrated with increasing concentrations of AREc-fos. Assigned ILV peaks, the new peaks appearing upon complex formation (*), and some representative ILV residues away from the RNA-binding site that showed chemical shift perturbations (boxed) are indicated. (B) The boxed peaks in A are shown at a similar contour level at individual titration points. The new peak emerging with increasing concentrations of RNA is shown by an arrow. (C) Results of NMR titration mapped onto the co-crystal structure of HuR-AREc-fos complex (PDB 4ED5). Protein and RNA are represented as in Fig 2. Assigned ILV residues are shown as sticks and colored as follows: RRM1/2 residues showing new complex peaks (red) and residues with chemical shift perturbations as indicated in B (yellow).
