Send to

Choose Destination
Biophys J. 2001 Apr;80(4):1802-9.

Localization of the extracellular end of the voltage sensor S4 in a potassium channel.

Author information

The Nobel Institute for Neurophysiology, Department of Neuroscience, Karolinska Institutet, SE-171 77 Stockholm, Sweden.


The opening and closing of the pore of voltage-gated ion channels is the basis for the nervous impulse. These conformational changes are triggered by the movement of an intrinsic voltage sensor, the fourth transmembrane segment, S4. The central problem of how the movement of S4 is coupled to channel opening and where S4 is located in relation to the pore is still unsolved. Here, we estimate the position of the extracellular end of S4 in the Shaker potassium channel by analyzing the electrostatic effect of introduced charges in the pore-forming motif (S5-S6). We also present a three-dimensional model for all transmembrane segments. Knowledge of this structure is essential for the attempts to understand how voltage opens these channels.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center