Fig 3.

Mobility change of Gαs after the initial binding to β₂AR either at the C-terminus (A) or the N-terminus (B). The theoretical value at each residue was calculated by mean squared fluctuation between Gαβγ(GDP) and pre-R-Gαβγ(GDP) in percentile and is displayed according to the indicated color map. The residue in blue (red) is considered to become rigid (flexible). (C) Schematic of the proposed binding event between Gαs (gray) and β₂AR (blue). Activated β₂AR may initially be bound to the N terminus of Gα, leading to a relatively flexible C terminus, which increases the probability that it will find its proper binding position to the receptor. Eventually, this binding event is completed by the C terminal binding.