Abstract
Four transmembrane segments from each of the β-, γ- and δ-protein subunits of the acetylcholine receptor (AChR) [Nature (1983) 301, 251–255], [Proc. Natl. Acad. Sci. USA (1983) 80, 1111–1115] have been selected on the basis of single group rotation (SGR) theory [Symp. Structure and Dynamics of Nucleic Acids and Proteins (Sept. 1982) abst. pp.52–53], [Biochem. Biophys. Res. Commun. (1983) 111, 1022–1029] and the hydrophobicity of amino acid sequences. One helix from each subunit is assigned to the AChR ion channel. Criteria for the selection of ion channel elements are outlined