An alignment of channel-lining residues for a range of eukaryotic Cys-loop receptors and prokaryotic homologues. As is common for these receptors, a prime notation is used to facilitate comparison between different subunits, with 0′ being the conserved charged residue at the start of M2. Grey indicates residue conservation. Accession numbers are: ELIC P0C7B7, GLIC Q7NDN8, 5-HT3P46098, nACh α1 P02708, Gly P23415, GABAA α1 P14867, GABAA β2 P47870, GABAA γ2 P18507, GluCl Q94900.