Title :
structure of the voltage-gated K⁺ channel Eag1 reveals an alternative voltage sensing mechanism
Abstract :
- Voltage-gated potassium (K(v)) channels are gated by the movement of the transmembrane voltage sensor, which is coupled, through the helical S4-S5 linker, to the potassium pore
- We determined the single-particle cryo-electron microscopy structure of mammalian K(v)10.1 , or Eag1 , bound to the channel inhibitor calmodulin , at 3 .78 angstrom resolution
- Unlike previous K(v) structures, the S4-S5 linker of Eag1 is a five-residue loop and the transmembrane segments are not domain swapped, which suggest an alternative mechanism of voltage-dependent gating
- Additionally, the structure and position of the S4-S5 linker allow calmodulin to bind to the intracellular domains and to close the potassium pore, independent of voltage-sensor position
- The structure reveals an alternative gating mechanism for K(v) channels and provides a template to further understand the gating properties of Eag1 and related channels