Accession Numbers Protein Data Bank accession codes for previously published X-ray crystal structures are: Ac-AChBP in complex with lobeline (2bys), epibatidine (2byq), imidacloprid (3c79), thiaclopri... (3c84), HEPES (2br7), polyethyleneglycol (2byn), DMXBA (2wnj), 4OH-DMXBA (2wn9), cocaine (2pgz), anabaseine (2wnl), in silico compound 31 (2w8f), MLA (2byr), in silico compound 35 (2w8g), sulfates (3gua), α-conotoxin ImI (2c9t and 2byp), α-conotoxin PnIA variant (2br8), α-conotoxin TxIA (2uz6), apo state (2w8e), Y53C-MMTS (2xz5) with acetylcholine, Y53C-MTSET (2xz6).