Fig. 2.

Backbone dynamics of syb-2. The ¹⁵N relaxation data recorded for syb-2 (1–96) are shown. (A) ¹⁵N R₁ relaxation rate constants recorded at 600 MHz versus residue. The red arrow highlights the unusually high values of ¹⁵N R₁. The red line corresponds to the linear fit indicating the increase of rigidity of the protein backbone versus residue. (B) {¹H}-¹⁵N NOE values versus residue increase linearly from the N terminus to the C terminus. The red line corresponds to the linear fitting indicating the increase of rigidity of the protein backbone versus residue. (C) ¹⁵N R_2,0 relaxation rate constants recorded at 600 MHz (derived from ¹⁵N R_1ρ with a 2-kHz RF field; R₁ contribution-corrected) plotted versus residue. Red arrows highlight the two maxima in the dataset. (D) Hahn-echo transverse relaxation rates, R_2β, at 800 MHz minus those measured at 600 MHz. Positive values indicate R_ex contributions due to conformational dynamics on a microsecond-millisecond time scale. Regions subject to such conformational exchange processes are highlighted by red arrows.