Figure 2.

SAXS and NMR analysis of RbBP5. (A) (¹H-¹⁵N)-TROSY spectra of the RbBP5_NTD β-propeller domain (left), RbBP5_CT (middle) and full-length RbBP5 (right). For the C-terminus (CT), the amide resonances are clustered between 7.5 and 8.5 ppm in the ¹H dimension indicating that it is unfolded, while the well-dispersed spectrum of the N-terminal domain (NTD) is consistent with our homology model and the reported crystal structure (54) (PDB ID: 5OV3). Overlay of spectra of RbBP5_NTD with RbBP5 (right) shows that some β-propeller resonances exhibit peak shifts. (B) A representative member of the most populated model reflects a structured NTD and a flexible, but non-random CT. (C) The clear difference in Rg distribution profiles for the initial pool of 30 000 models (with random conformations of the CT (dashed)) versus the SAXS-derived ensemble (solid) indicate that the CT, in the context of full-length RbBP5, is not randomly disordered. Inset shows the pair distance distribution function P(r) calculated for the experimental data (black circles) and for the SAXS-derived ensemble (red line).