Structure of CaM (right) and its loop III (inside left box). In the latter, the five colored residues coordinate to Ca2+, Asp-93 (green), Asn-95 (blue), Asn-97 (magenta), Tyr-99 (yellow), and Glu-104 (cyan). The figure is prepared with MOLSCRIPT (42), Raster3D (43), and PyMOL (44).