Nullspace Sampling with Holonomic Constraints Reveals Molecular Mechanisms of Protein Gαs
Fig 5
Diffusion of the Gαs AH-domain opening angle in the ensemble.
The change in opening angle between the AH-domain and the Ras-domain is shown as sampling progresses for KGS, iMC (left panel), and CONCOORD (right panel). For KGS, the inactive AH-domain opens to nearly 30 degrees (dark-red), while the active AH-domain ranges from 84.8 to 96.5 degrees (red). The inactive opening angle of iMC reaches 9.9 degrees, and ranges from 79.6 to 103.7 degrees for the active AH-domain. The opening angle of activated Gαs in the β2AR:Gαs crystal structure is indicated in the inset. The inactive opening angle of CONCOORD reaches around 18 degrees, and ranges from 74.6 to 111.4 degrees for the active AH-domain. For the active state, iMC and CONCOORD sample uniformly around the starting angle. The angle of the KGS samples slowly decreases towards the inactive state.