The structure of the G protein heterotrimer G_iα1β₁γ₂

Authors

Mark A. Wall, University of Texas Southwestern Medical Center
David E. Coleman, University of Texas Southwestern Medical Center
Ethan Lee, University of Texas Southwestern Medical Center
Jorge A. Iñiguez-Lluhi, University of Texas Southwestern Medical Center
Bruce A. Posner, University of Texas Southwestern Medical Center
Alfred G. Gilman, University of Texas Southwestern Medical Center
Stephen R. Sprang, University of Montana

Document Type

Article

Publication Title

Cell

Publication Date

12-15-1995

Volume

83

Issue

6

Disciplines

Biology | Life Sciences

Abstract

The crystallographic structure of the G protein heterotrimer G_iα1(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.

DOI

https://doi.org/10.1016/0092-8674(95)90220-1

Rights

© 1995 Cell Press

Recommended Citation

Wall, Mark A.; Coleman, David E.; Lee, Ethan; Iñiguez-Lluhi, Jorge A.; Posner, Bruce A.; Gilman, Alfred G.; and Sprang, Stephen R., "The structure of the G protein heterotrimer G_iα1β₁γ₂" (1995). Biological Sciences Faculty Publications. 543.
https://scholarworks.umt.edu/biosci_pubs/543