Figure 1

Calculated membrane binding modes for C2 domains of cPLA _2α (A), PKCα-C2 with lipid ligands PS and PI(4,5)P ₂ (B), sytI-C2A (C) and sytI-C2B (D). The backbone of C2 domains and the specific lipid ligands are shown in ribbon and stick models, respectively. Ca²⁺ ions are shown as balls colored magenta. Residues identified as penetrating to a non-polar environment by SDSL are colored red. Cationic residues involved in ligand binding and membrane interactions are colored blue. The hydrocarbon core boundary at the cytoplasmic side is indicated by blue dots. The layer of lipid phosphates ("P") is shown by gold dots (at 5 Å outside the hydrocarbon boundary [28]). The center of the membrane is indicated by grey dots (at 15 Å inside the boundary). All Figures were generated by PyMol.