FIGURE 6.

Analysis of the interactions of PDZ2+²⁷⁰ with the C-terminal EB. A, top view of the C-terminal EB peptide-binding site in PDZ2CT. Residues that experience severe exchange broadening or large chemical shift perturbation (>0.15 ppm) are shown in orange, and their side chains are marked in yellow. B, a view of the EB peptide (green) with L358 inserted into the hydrophobic pocket (yellow) in the PDZ2 domain. The C-terminal charge of L358 (red) is complemented by the amide groups from the exposed CB loop of PDZ2. Coordinates for this figure are derived from the calculation assuming helix formation in the C-terminal EB domain. Shown are the ¹⁵N HSQC spectrum of wild-type PDZ2CT domain (black) overlaid with mutant PDZ2CT(F355A) (red) (C) and overlaid with PDZ2CT(F355P) (red) (D) at 30 °C. Residues with significant chemical shift perturbation are annotated in the overlay plots in C and D.