Signaling with Phosphoinositides: Better than Binary

Structure of the ENTH domain of CALM bound to the PI4,5P₂ head group. A gray backbone ribbon depicts the nine α-helices of the CALM structure; the lighter shade indicates the core ENTH domain (16). The side chains of the three lysines (blue) and the histidine (green) that coordinate the phosphorylated inositol (yellow and red) are also shown. (See text for details.)