A general strategy to characterize calmodulin-calcium complexes involved in CaM-target recognition: DAPK and EGFR calmodulin binding domains interact with different calmodulin-calcium complexes

► CaM interaction with its target peptides depends on the number of Ca2+ bound. ► CaM-Ca interacts with the unphosphorylated DAPK CaM binding domain. ► CaM-Ca3 interacts with the phosphorylated DAPK CaM binding domain peptide. ► CaM with four Ca2+ is required for interaction with the EGFR CaM binding domain.