Conformational dynamics of yeast calmodulin in the Ca2+-bound state probed using NMR relaxation dispersion

► Ca2+-bound calmodulin from yeast (yCaM) takes on a compact, collapsed structure. ► The target-binding site of yCaM is autoinhibited. ► NMR relaxation dispersion revealed the existence of the minor structural state. ► The minor structural state was not observed in a disulfide mutant.