Primary sequence analysis and folding behavior of EF hands in relation to the mechanism of action of troponin C and calmodulin.

The primary sequence of EF hands encodes for elements of secondary structure which includes the presence of hydrophobic and charged domains in the helical regions of these sites. The hydrophobic and charged surfaces located in the N-terminal region of EF hands offer a potential site of interaction with complimentary surfaces on target proteins. Although the binding of calcium to the EF hands of calmodulin and troponin C may lead to a local exposure of these domains, it is the tertiary structure of these proteins that probably dictates the extent to which these domains are exposed and the selectively of these proteins for target proteins.