The M2 protein of influenza A virus is a proton channel. Its function is essential for productive infection by the virus.
See Category:Proton_channel for a list of all proton channel structures.
In January, 2008, crystallographic and NMR structures were published side by side in Nature for the transmembrane domains of the M2 protein: 3bkd to 2rlf. The former appeared to be in an open conformation blocked by amantadine, while the latter appeared to be in a closed conformation stabilized by rimantadine. (Neither drug is shown in the morph at right.)
At right is a linear-interpolation morph between 3BKD and 2RLF, showing the proposed opening and closing of this channel.
In addition to watching the animation as alpha-helical ribbons, it is useful to watch it . Be sure to rotate the molecule with your mouse to watch the animation from different perspectives!
are believed to be crucial for pH-dependent gating.
(The apparent collapse and re-expansion of their sidechains is an artifact due to the linear interpolation method of morphing.) Here are His and Trp .
To be explained in a later revision, along with new scenes:
Morph from Yale
3D structures of ion channels
Ion channels
Additional Resources
For additional information, see: Influenza
For additional information, see: Membrane Channels & Pumps