Sequence of context dependence of EF-hand loop dynamics. An 15N relaxation study of calcium-binding site mutant of calbindin D9k

The effect of structural context and amino acid sequence on the backbone dynamics of helix-loop-helix calcium-binding motifs (EF-hand) was examined via 15N spin relaxation measurements performed on the calcium-free state of the calbindin D9k mutant. The findings were then analyzed relative to a previous study regarding the apo state of the wild-type-like P43G D9k mutant. The results revealed that the N-terminal EF-hand facilitates the formation of a stable structure that enables calcium binding with only minor modifications.