Journal
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Volume 15, Issue 5, Pages 7841-7864Publisher
MDPI
DOI: 10.3390/ijms15057841
Keywords
GPCR; pi-helix; alpha-bulge; GPCR activation; random forest; structure-function
Ask authors/readers for more resources
Agonist binding is related to a series of motions in G protein-coupled receptors (GPCRs) that result in the separation of transmembrane helices III and VI at their cytosolic ends and subsequent G protein binding. A large number of smaller motions also seem to be associated with activation. Most helices in GPCRs are highly irregular and often contain kinks, with extensive literature already available about the role of prolines in kink formation and the precise function of these kinks. GPCR transmembrane helices also contain many alpha-bulges. In this article we aim to draw attention to the role of these alpha-bulges in ligand and G-protein binding, as well as their role in several aspects of the mobility associated with GPCR activation. This mobility includes regularization and translation of helix III in the extracellular direction, a rotation of the entire helix VI, an inward movement of the helices near the extracellular side, and a concerted motion of the cytosolic ends of the helices that makes their orientation appear more circular and that opens up space for the G protein to bind. In several cases, alpha-bulges either appear or disappear as part of the activation process.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available