Figure 2: Structure of AChBP from Capitellateleta (Ct-AChBP) complexed with the partial agonistslobeline(A-C) and varenicline(D), respectively (modified from [30]). AChBP-lobeline structures showing the N-terminus pointing away (A) or toward (B) the viewer, and the subunit interface (principal face in yellow and complementary face in blue) towards the viewer (C). Each of the five subunits is displayed in a different color. Oxygen, red; nitrogen,blue; sulfur, green. The glycosyl chain N-linked to N122 is shown in magenta. The paucimannose chain iscomposed of N-acetylglucosamine (NAG), α-Dmannose (α-MAN), and β-D-mannose(β-MAN). (D) Ct-AChBP-varenicline complex. Lobeline and varenicline complexed with Ct-AChBP are shown as spheres, whereas the insets show the electron density of each molecule.