Fig. 2.

(a) Slow chemical exchange for G113 (in rounded rectangle) and G96 (in circle). Both residues display a single peak at 0 MEs Ca²⁺, followed by the emergence of a second peak at 1 ME Ca²⁺. At 2 MEs Ca²⁺, the original peak in each pair is undetectable, leaving only the second peak. (b) Fast chemical exchange for G23 and G59. (c) CaM (3cln.pdb) with residues color-labeled to indicate fast (blue), intermediate (purple) and slow (red) chemical exchange. The carboxyl-rich central linker is highlighted in the bracket.