Figure 3From: The 3.5 ångström X−ray structure of the human connexin26 gap junction channel is unlikely that of a fully open channelFormation of salt bridges in different umbrella sampling windows. Left panels (A−D) show side view representations of the calcein molecule in the channel pore; residues that interact with it are drawn in ball−and−stick style. Right panels (A−D) show time−course plots of the distance between one carboxy group of calcein and the amino group of interacting residues. (A) Calcein interacts with a Met1 alone. (B) Moving along the axis of the pore, calcein is found in a favorable position to interact both with Met1 and with Lys41. (C, D) After breaking the interaction with Met1, calcein interacts only with Lys41; in this zone, salt bridges are less stable due to calcein interacting simultaneously with Lys41 residues from different protomers.Back to article page