Figure 4.

Residues with non-linear temperature coefficients for amide hydrogens are sampling a different chemical environment above the break. (a,b) Ca²⁺-binding sites III and IV reveal multiple residues with non-linear temperature dependence. Residues listed to the left of each panel are located before or after the cartoons in panels a and b (NL – nonlinear, L – linear and NA – not analysed). (c,d) Collection of ¹H chemical shifts with nonlinear behavior for residues located within sites III and IV, respectively. Numbers beside line segments in (c–d) represent temperature coefficients in ppb/°C. Calcium ions (green) are depicted in both sites but available evidence indicates they are bound only weakly (or not at all) in sites III and IV of D145E.