Figure 3.

Rearrangements upon agonist binding. (A) The epibatidine‐bound α2 subunit showing the interaction of loop‐C Tyr²¹⁹ with the β7‐strand Lys¹⁷⁴, probably weakening the interaction between the residues of β7 and β10 strands. The (+) side is shown in green, the agonist in magenta and the (−) subunit in cyan. (B) Similarly for the α4 subunit bound to nicotine. Colours as in (A). (C) The β2‐subunit Asp198 on β10‐strand acquires a rotamer never observed before in α subunits. It is further stabilized by interactions with two positively charged residues of β7 strand. The β2 subunit is shown in cyan. α4 and β2 subunits were retrieved from PDB ID: 5KXI (Morales‐Perez et al., 2016) and α2 subunit from PDB ID: 5FJV (Kouvatsos et al., 2016). The coordinates of all the structures depicted were retrieved from Protein Data Bank (http://www.wwpdb.org), and PyMol (http://www.pymol.org) was used to generate the figures.