Fig. 2: Subtle dynamic adaptations within the PDZ domain assessed by backbone and ALVIT methyl dynamics.
a ΔR2eff values for the backbone amide groups, obtained from the difference of R2eff at the lowest and highest CPMG frequency υCPMG, at the indicated temperatures. Residues exchange broadened are highlighted by purple bars; unassigned residues indicated by an asterisk (*). Error bars indicate the standard fitting error obtained from the nonlinear least-squares minimization of one experiment (n = 1). b Amplitude of the CPMG relaxation dispersion profiles ΔR2eff at 21.1 T of an [U-15N,13C]–PDZ sample at 298 K. c Rate constants of the dynamic process (τex) and the relative populations of PDZ states obtained from a global fit of the CPMG relaxation dispersion data. Error bars indicate the standard fitting error obtained from the nonlinear least-squares minimization of one experiment (n = 1). d, e Local methyl group dynamics on the pico- to nanosecond timescale probed by methyl single-quantum (SQ) and triple-quantum (TQ) relaxation experiments showing the product of the local order parameter and the overall tumbling constant, S2axis•τC. Measurements were performed on an [U-2H, Ile-δ1-13CH3, Leu, Val-13CH3, Ala-13CH3, Thr-γ2-13CH3]–PDZ sample at 298 K. Methyl groups (spheres) and the obtained S2axis•τC-values (yellow-to-blue gradient) (d). S2axis•τC-values plotted against the HtrA2-PDZ amino acid sequence (e). Error bars indicate the standard fitting error obtained from the nonlinear least-squares minimization of one experiment (n = 1). f Amplitude of the CPMG relaxation dispersion profiles ΔR2eff at 16.4 T. Source data are provided as a Source Data File.
