Cover picture: (Top) The crystal structure of the Kv1.2 channel (gray) and a structural model of the open activated conformation (color) deduced from electrophysiological data and molecular dynamics simulations. The pore domain is green, the S2 is yellow, S3 is red, and S4 is blue. The open conformation is stabilized by a His-Zn2+-His metal bridge between R294 in S4 and position A351 in S5. (Bottom) The electrophysiological data used to constrain the modeling. (Left) The open-activated state of the Kv1.2 channel is stabilized by the formation of the His-Zn2+-His metal bridge, as reflected in the left shift of the G(V) curve. (Right) The bridge has high affinity with a half-maximal Zn2+ concentration ~360 nM (see article by Lewis et al., 549–561).