A Dynamic Model of Interactions of Ca2+, Calmodulin, and Catalytic Subunits of Ca2+/Calmodulin-Dependent Protein Kinase II
The top layer (A) represents binding of Ca2+ to CaM. Red arrows correspond to Ca2+ binding to the C-terminus, and blue arrows binding to the N-terminus. The bottom layer (B) represents Ca2+ binding to CaM while CaM is bound to CaMKII. The CaM species are denoted as CaMnNcC with n, c , such that n is the number of Ca2+ bound to the amino (N) terminus and c is the number of Ca2+ bound to the carboxyl (C) terminus. The species of CaM bound to mCaMKII are denoted K•CaMnNcC. For convenience, we use CaM4 and K•CaM4 to denote species with n = c = 2, and CaM0 and K•CaM0 to denote those with n = c = 0. (C) The full model is represented as a cube, with yellow arrows indicating binding between CaMnNcC and mCaMKII.