(A) The VP40EΔN hexamer structure assembled across a crystallographic 2-fold axis (red oval), is illustrated with the NTDs colored alternatively in light or dark blue and the CTDs colored in light or dark orange. The NTDs and CTDs are numbered according to the protomer to which they belong. The disordered “sprung” CTDs are modeled as circles (to scale). Below, a 90° rotation in which the dimeric and oligomeric interfaces are indicated by yellow and green lines, respectively. (B) The oligomerization interface is displayed from the VP40 hexamer, centered on residue W95 (yellow). (C) A section of the VP40EΔN hexamer crystal packing is shown, the NTD is colored blue and the CTD is colored orange. Here the uninterrupted filament structures formed via the CTD-to-CTD interface (one filament indicated by a red line) as well as the large solvent channels that contain the “sprung” CTDs can be seen.