GoLoco motif proteins binding to Galpha(i1): insights from molecular simulations.

Molecular dynamics simulations, computational alanine scanning and sequence analysis were used to investigate the structural properties of the Galpha(i1)/GoLoco peptide complex. Using these methodologies, binding of the GoLoco motif peptide to the Galpha(i1) subunit was found to restrict the relative movement of the helical and catalytic domains in the Galpha(i1) subunit, which is in agreement with a proposed mechanism of GDP dissociation inhibition by GoLoco motif proteins. In addition, the results provide further insights into the role of the "Switch IV" region located within the helical domain of Galpha, the conformation of which might be important for interactions with various Galpha partners.