Subunit organization and structure of an acetylcholine receptor.
We have learned the positions of the alpha-subunits around the AChR rosette and the location of the toxin on the synaptic crest. A charge/hydrophobic character map of the 40 A X 30 A receptor surface that binds alpha-bungarotoxin has been constructed. A beta-structure domain surrounds the agonist binding site on the alpha-subunits, as predicted by amphipathic Fourier sequence analysis. The ion channel may be constructed from five amphipathic helices, which insert into the bilayer as the alpha2 beta gamma delta subunits come together. They form a water-filled channel on one side and interface with hydrophobic helices in each subunit on the other.
D000595:Amino Acid Sequence; D000818:Animals; D000936:Antigen-Antibody Complex; D004557:Electric Organ / Q000378:metabolism; D007140:Immunoglobulin Fab Fragments; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D008958:Models, Molecular; D011487:Protein Conformation; D011950:Receptors, Cholinergic / Q000378:metabolism; D014101:Torpedo; D014961:X-Ray Diffraction
D000936:Antigen-Antibody Complex; D007140:Immunoglobulin Fab Fragments; D046911:Macromolecular Substances; D011950:Receptors, Cholinergic