Fig. 2.

Comparison of chimeric KirBac-GIRK1 structures in “closed” (green) and “open” (orange) states with MPD-bound IRK1 (gray). MPD is shown as a CPK model with hydroxyl groups in red. IRK1 is more similar to the putative open- than closed-state GIRK1 structures in the region of the hydrophobic MPD-binding pocket. Note movement of the βL-βM domain (top), implicated previously in G_βγ activation, between the putative open and closed configurations. In the closed state, several amino acid side chains occupy the pocket in which, in IRK1, MPD is bound. Figure modified from Aryal and colleagues (2009).