Anna Stary-Weinzinger (left), Harald Bernsteiner (right), and colleagues use MD simulations to provide new details about the gating and conductance of the inwardly rectifying K⁺ channel GIRK2. The crystal structure of the channel bound to its activator, PIP₂, shows the position of the HBC and G-loop gates, as well as five K⁺ ions (pink spheres) passing through the selectivity filter via what the simulations suggest is a direct knock-on mechanism.