Figure 2.

Interdomain flexibility of the TTD–PHD module from NMR relaxation and SAXS data. A, local correlation time (τ_c) determined for each residue from experimental T₁/T₂ ratios (black spheres). The apparent global correlation times of the two domains derived by fitting to a standard diffusion model for each domain separately (blue horizontal line). The theoretical τ_c values predicted by HYDRONMR (20) for full-length TTD–PHD (red horizontal line) and for individual domains separately (magenta horizontal line). B and C, distribution of HYCUD-predicted (22) global τ_c values in MDP_IN/OUT and MDP_IN for the TTD (B) and PHD (C). D and E, goodness of fit of MDP_IN/OUT (D) and MDP_IN (E) to SAXS (χ_saxs, black circles) and NMR (χ_relax, red circles) data shown as a function of the weighting factor α. Ensemble fitting to both SAXS and NMR data were performed simultaneously by minimizing residual χ² = χ_saxs² + α · χ_relax² at different values of α.