Binding site of the G-protein α s subunit (PDB ID 1azs) divided into two modules. This division coincides with the specialized regions of this binding site for ligand binding only (pink module) and ligand binding and information transfer (blue module). The binding site residues are depicted in spacefill. Modular regions not involved in the binding site are depicted in green.
del Sol et al. Genome Biology 2007 8:R92 doi:10.1186/gb-2007-8-5-r92