Figure 1. The pore domain/VSD interface is important for C-type inactivation.

(a,b) Molecular structure of the Shaker Kv channel (top view in a, side view in b). Four identical voltage-sensor domains (VSDs) surround the pore domain. The voltage sensor S4 (positively charged residues in blue) is in an activated up-state. For clarity, the VSDs in the front and the back are removed (b). Labelled residues are discussed in this paper. (c–e) Effects of different mutations and pH on the inactivation time course and steady-state current. Test step voltage = +80 mV. Holding voltage = −80 mV. pH = 7.4 if not otherwise noted.