Figure 1: Torpedo AChR model showing the structural differences between theopen (magenta) and closed (blue) states at 6.2 Å resolution (modified from [20] ). Only subtle differences can be seen between both conformational states. AChRs are formed by three main domains: The extracellular domain shows the β-strands forming the β-sandwich structure.The transmembrane domain is formed by 20 α-helices, four α-helices per subunit. The cytoplasmic domainis the smaller domain.