Figure 3.

Zwitterionic lipid binding to the R3.50 component of the ionic lock. (A and B) Representative conformations of (A) active, lipid bound and (B) inactive, lipid unbound states. C_α atoms used in evaluation of d_H3–H6 are shown as yellow spheres. (C and D) Probability histograms of (C) d_H3–H6 and (D) d_lock for (solid black line) lipid-unbound and (dashed gray line) lipid-bound states. (E) Probability histograms of the minimum N_η-O distance between R3.50 and a lipid, d_R3.50-lipid, for simulations of (solid red line) G-protein- and (dashed blue line) nanobody-derived structures. Probability density maps depicting d_R3.50-lipid vs. d_H3–H6 and d_lock are presented in Fig. S4. To see this figure in color, go online.