Diverse gating in K+ channels: Differential role of the pore-helix glutamate in stabilizing the channel pore

► The Glu-Asp carboxyl-carboxylate interaction stabilizes the pore of the KcsA K+ channel. ► In contrast, a salt bridge (Glu-Arg) controls the pore stability in most Kir channels. ► The pore-helix Glu has a differential role in stabilizing the pore structure. ► Such differences may explain a diverse gating pattern in K+ channels.