Fig. 8.

The structure of pore funnel and pore plug. a The six NTHs form pore funnel, which is stabilized by circular hydrogen bond network (red dashed lines) at the bottom of it and attached to the inner wall of the channel by hydrophobic interactions (orange dashed lines). These interactions are formed between neighboring monomers. b Superposition of the atomic model of wild-type Cx26 gap junction channel (ribbon representation: green) into the electron density map of Met34Ala mutant Cx26 (surface representation: gray)