Trimeric Gabg protein coupling to a 3D model of G protein-coupled receptors confirming a new molecular mechanism for activation.

: The present-day model for G protein activation and the associated theory on how a G protein-coupled receptor may activate the G protein are summarized. Experimental data are outlined which seem not to be in accordance with this present-day model. An alternative molecular mechanism for ternary complex activation is presented together with a three-dimensional model for a receptor coupled to the appropriate trimeric G protein. This 3D structure confirms our new molecular mechanism of activation.