M2 Proton Channel: Difference between revisions

The hydrophilic residues in each α-helix monomer are oriented towards the pore lumen.<ref name="Wu" /> The <scene name='User:Sarah_Henke/Sandbox_1/Hydrophobic/1'>hydrophobic</scene> residues will be in contact with the membrane (Color code= {{Template:ColorKey_Hydrophobic}} or {{Template:ColorKey_Polar}}). Most of the residues in the M2 channel are hydrophobic except Ser31 Gly34, and His37.<ref name="Wu" /> The central cavity of the M2 proton channel is most constricted near residue <scene name='User:Sarah_Henke/Sandbox_1/Val27/1'>Val27</scene>.<ref name="Stouffer" />  After this residue, the cavity opens to a water-filled pore that is lined with residues <scene name='User:Sarah_Henke/Sandbox_1/Pore/1'>Ala30, Ser31, and Gly34</scene>.<ref name="Stouffer" />  Mutagenesis studies have found that the residues facing the pore are Val27, Ala30, Ser31, Gly34, His37, Leu38, and Trp41.<ref name="Wu" />  The central cavity also constricts at residues His37 and Trp41.<ref name="Stouffer" />  Residues <scene name='User:Sarah_Henke/Sandbox_1/His_37/1'>His37</scene> and <scene name='User:Sarah_Henke/Sandbox_1/Trp20/1'>Trp41</scene> play a key role in the gating mechanism.<ref name="Wu" /> In the closed state, the His37 and Trp41 residues block the channel, preventing proton conductance. <ref name="Lear">PMID:12972146 </ref>