Figure 7.

Electrostatic properties of the homology models for the PLCβ PH domains. Electrostatic equipotential profiles for the PLCβ PH domain models were calculated and visualized in GRASP (Nicholls et al. 1991): β1-PH (A), β2-PH (B), β3-PH (C), and β4-PH (D). The loops that correspond to the PI(4,5)P₂-binding loops in the PLCδ1-PH structure are located at the bottom of the images. All β PH domains are in an orientation similar to that as the PLCδ PH domains in Figure 2 ▶, except for β2-PH (B), which is rotated 180 degrees about the vertical axis to highlight its large basic surface patch. Clusters of surface-exposed hydrophobic residues (Leu, Phe, Tyr, Trp) are colored green. The blue and red meshes represent, respectively, the +1 kT/e and −1 kT/e equipotential contours for 0.1 M KCl.