This figure illustrates the progress of 2-AG into the binding pocket. The color scale represents the percentage of the trajectory in which any portion of 2-AG is within 4 Å of residues on CB2 (defined here as within contact distance). Residues within contact distance are listed on the right and are color-coded according to this scale. A, in trajectory C (40–275 ns), the 2-AG has partitioned out of bulk lipid and contacts residues in or near the TMH6/7 interface. Highest contact is with F7.35(281) and C7.38(284). B, in trajectory E (0–52 ns; up to the point of headgroup insertion), 2-AG interaction with residues in the TMH6/7 interface increases with greater than 80% contact occurring with F7.35(281), S7.39(285), and C6.47(257). C, in trajectory E, after 2-AG entry into CB2 (53–127 ns), 2-AG begins to contact binding pocket residues on TMH3 (V3.32(113)), TMH6 (W6.48(258)), TMH7 (C7.42(288)), and the EC-3 loop (D(275)). D, subsequent to protonation, in trajectory G (from 913 to 1668 ns), 2-AG contacts multiple residues on TMH3/6/7 and the EC-3 loop with formation of hydrogen bonds with D(275) in the EC-3 loop and to a lesser extent with S7.39(285) (see supplemental Table S1).