Crystal structure of a voltage-gated K⁺ channel pore module in a closed state in lipid membranes

Voltage-gated K⁺ channels underlie the electrical excitability of cells. Each subunit of the functional tetramer consists of the tandem fusion of two modules, an N-terminal voltage-sensor and a C-terminal pore. To investigate how sensor coupling to the pore generates voltage-dependent channel opening, we solved the crystal structure and characterized the function of a voltage-gated K⁺ channel pore in a lipid membrane. The structure of a functional channel in a membrane environment at 3.1Åresolution establishes an unprecedented connection between channel structure and function. The structure is unique in delineating an ion-occupied ready to conduct selectivity filter, a confined aqueous cavity, and a closed activation gate, embodying a dynamic entity trapped in an unstable closed state.