Subunit Interactions of Heterotrimeric G-Proteins

摘要: A defining feature of the GTP-binding α subunit heterotrimeric G-proteins is its interaction with βγ subunit. Although G proteins are heterotrimers, they functional dimers because β and γ subunits appear not to dissociate under native conditions. The equilibrium between associated dissociated states a controlled by conformational changes in that accompany guanine nucleotide binding hydrolysis. As diagrammed Fig. 1, when nucleoside diphosphate bound α, form favored. When exchanged for triphosphate, shifts toward dissociation.