Figure 2.

Myristoyl switch model for MA^Gag recognition of the plasma membrane (Saad et al. 2006). MA^Gag (yellow) proteins are shown with the aliphatic myristoyl group (brown) sequestered within the soluble protein (left, 1UPH), and with the myristoyl group extruded into the membrane when bound to the plasma membrane specific phosphatidyl inositide, PI(4,5)P₂, shown in red (right, 2H3F). The PI(4,5)P₂ inositol head group and unsaturated 2′-fatty acid bind within MA, allosterically inducing extrusion of the myristoyl group, whereas the saturated 1′-fatty acid of PI(4,5)P₂ remains embedded in the membrane. Basic residues on the membrane binding surface of MA^Gag are shown in blue.