Fig. 4: Required 3-fold hexamers in icosahedral capsids.
a Capsids with hexamers not centered on the 3-fold axis (top) and a hexamer centered on the 3-fold axis (bottom). The triangulation number, T(h,k), is displayed for each capsid. Patience and Adjutor are both T = 7 capsids. The semi-transparent triangle indicates the true 3-fold axis in each capsid. b Icosahedral capsid with a hexamer on the 3-fold axis illustrating the hexagonal coordinates (top). The locations of the nearest pentamer (h,k) and central hexamer (hH,kH) are displayed. The dotted lines connect the nearby pentamers (h = 2, k = 2). (Bottom) The same capsid highlighting triangular areas defined by the pentamers, T(h,k) (in blue), and the central hexamer, T(hH,kH) (in orange). c Reconstruction of SIO-2 phage procapsid displaying the full T(2,2) = 12 architecture displaying the path connecting pentamers with black dashed lines (top), and the region around the 3-fold axis displaying the symmetrical hexamer surrounded by split hexamers (bottom). The white polygons highlight the symmetric and split hexamers. The procapsid was rendered from the map EMD-5383 using ChimeraX.
