The M2 channel with the proton-conducting water wire disrupted by the presence of the anti-flu drug amantadine. The helices of the M2 channel (blue), the proton-gating His37 residues (mauve), and the proton-blocking amantadine molecule (orange) are depicted. The lipid bi-layer membrane is not shown so that the channel can be seen more clearly. Image courtesy of Hanning Chen.