FIG. 9.

Proposed mechanism for binding to CD46. Shown is a view into the central Ad11-CD46 contact area around Arg280. CD46 and the Ad11 knob are shown in orange and blue, respectively. As CD46 approaches the Ad11 knob, Arg280 flips over from its “off position” near Arg291 (A) and swings next to CD46 Phe35 and Ad11 Arg279 into the “on position” (B). A theoretical model for an Ad7 knob-CD46 complex is shown in panel C, with the Ad7 knob in yellow and CD46 in grey. A Gln at position 279 would not interfere sterically with a rotating Arg280.