Beta2 adrenergic receptor-Gs protein complex: Difference between revisions

The Gαs subunit consists of two domains, the <scene name='70/701430/Alpharas/2'>Ras domain (GαsRas)</scene> and the <scene name='70/701430/Alphahelical/2'>α-helical domain (GαsAH)</scene>. A previous structure of a GTPγS bound Gαs protein (PDB ID: [[1AZT]]) showed that both domains are involved in nucleotide binding, as the nucleotide-binding pocket of the Gαs subunit is formed by the interface between GαsRas and GαsAH. It was also previously known that the GsαAH domain has a variable position relative to the GsαRas domain between this GTP bound (active) state and the nucleotide free state. However, the β2AR–Gs complex structure of the receptor attached to the empty (no guanosine phosphate attached) G protein enabled comparing it to the active (GTP bound) structure and by that showing <scene name='70/701430/Gamorph/2'>how large this displacement is</scene> - this is probably the most surprising observation in the β2AR–Gs complex .