We used a computer-based prediction algorithm to identify probable coiled-coil segments at the N-termini of G protein α, β and γ subunits. This result indicates that G protein trimers may form via a three-stranded coiled coil. Previous biochemical results had shown that the N-termini of α and β are involved in subunit interactions. Here we present a structural model for the N-terminal domain of βγ and a hypothesis for the reversible association of α to βγ.
