FIG. 2.

HBoV cryo-reconstruction. (A) Stereo, shaded-surface representation of the entire capsid viewed along a 2-fold direction. The black equilateral triangle bounded by two 3-fold (labeled 3) axes, separated by a 2-fold (labeled 2) axis, and by a 5-fold (labeled 5) axis identifies one asymmetric unit of the icosahedral capsid. (B) Same structure as in panel A but with the front half removed and generated as a perspective view. (C) Central cross-section of the reconstructed map, with highest- and lowest-density features depicted in black and white, respectively. Long arrows highlight the two- (2), three- (3), and 5-fold (5) axes that lie in the plane of the cross-section in one quadrant. Density “plugging” the 5-fold channel at low radii is indicated by the short, black arrow for one channel. (D) Enlarged view of upper left quadrant from panel C with circles drawn at radii corresponding to the radial density projections shown in Fig. 4. Density at the base of the channel modeled as residues 28 to 36 is indicated by an asterisk in panels C and D.