Abstract
The crystallographic structure of the G protein heterotrimer Giα1(GDP)β1γ2 (at 2.3 A) reveals two nonoverlapping regions of contact between α and β, an extended interface between β and nearly all of γ, and limited interaction of α with γ. The major α/β interface covers switch II of α, and GTP-induced rearrangement of switch II causes subunit dissociation during signaling. Alterations in GDP binding in the heterotrimer (compared with α-GDP) explain stabilization of the inactive conformation of α by βγ. Repeated WD motifs in β form a circularized sevenfold β propeller. The conserved cores of these motifs are a scaffold for display of their more variable linkers on the exterior face of each propeller blade.
| Original language | English |
|---|---|
| Pages (from-to) | 1047-1058 |
| Number of pages | 12 |
| Journal | Cell |
| Volume | 83 |
| Issue number | 6 |
| DOIs | |
| State | Published - Dec 15 1995 |
Funding
Acknowledgments We are grateful to Albert Berghuis, Jim Naismith, and Ward Coates for assistance with data collection and processing; to Brian Sutton and Orelia Ortiz for assistance with illustrations; to Elliott M. Ross, Eva Neer, and Mark Mixon for helpful discussion; and to Marian Stanzel for skilled technical assistance. This work was supported by National Institutes of Health (NIH) grant DK46371 and Welch Foundation grant I-1229 to (S. R. S.) and by NIH grant GM34497, American Cancer Society grant BE30-0, Welch Foundation grant I-1 271, and the Raymond and Ellen Willie Chair of Molecular Neuropharmacology (to A. G. G.).
| Funders | Funder number |
|---|---|
| American Cancer Society | BE30-0, I-1 271 |
| R01DK046371 | |
| GM34497, I-1229 |