The structural basis of the dominant negative phenotype of the Gαi1β1γ2 G203A/A326S heterotrimer.

ABSTRACT:

Aim

Dominant negative mutant G proteins have provided critical insight into the mechanisms of G protein-coupled receptor (GPCR) signaling, but the mechanisms underlying the dominant negative characteristics are not completely understood. The aim of this study was to determine the structure of the dominant negative Gαi1β1γ2 G203A/A326S complex (Gi-DN) and to reveal the structural basis of the mutation-induced phenotype of Gαi1β1γ2.

Methods

The three subunits of the Gi-DN complex were co-expressed with a baculovirus expression system. The Gi-DN heterotrimer was purified, and the structure of its complex with GDP was determined through X-ray crystallography.

Results

The Gi-DN heterotrimer structure revealed a dual mechanism underlying the dominant negative characteristic

SUBMITTER: Liu P 

PROVIDER: S-EPMC5022103 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature