Cooperative Transition between Open and Closed Conformations in Potassium Channels
Figure 2
Dynamic fluctuations in the MthK channel.
The second slowest mode of fluctuations of the channel is presented from a side view in the upper panels ((A) and (C)) and from an intacellular view in the lower panels ((D) and (F)). The X-ray structure of MthK (PDB identifier 1lnq) is presented in the panels in the middle ((B) and (E)). The color scheme is the same as in Figure 1. To close the pore, i.e., to switch from the open conformation of “A” and “D” to the closed conformation of “C” and “F”, the inner and outer helices bend around their hinge sites, and the inner helices rotate in a counterclockwise direction. The arrows mark the rotations of the inner helices in each subunit. The picture was prepared using Pymol [64].