On the left the protein is represented in cartoon format, coloured according to secondary structure. The sidechain of L6 is shown as sticks to emphasise that it is this residue that results in pore closure. On the right P1, H12, T48, Q50, and D51 are represented as sticks to show that the movement of the β-hairpin is driven by the formation of a salt-bridge between H12 and D51. Distances shown are in Ångstroms.