FIG. 3.
Visualization of icosahedrally ordered tegument. (a) HSV-1 virion reconstruction displayed at 1.0ς. At this density threshold, the nonicosahedrally related densities in the tegument/membrane layers are not visible. (b) HSV-1 B-capsid reconstruction at the same resolution as the virion reconstruction (20 Å) displayed also at 1.0ς. (c) Difference map between the virion and B-capsid reconstructions. In this display, the densities inside the capsid shell are excluded for clarity. Consequently, differences occurring at all of the pentonal positions including those on the hemisphere facing toward (labeled 1, 2, and 3) and away from (labeled 4, 5, and 6) the observer can be seen. (d) Superposition of the difference map on the B-capsid reconstruction (gray). The tegument proteins are highlighted in color. Labeled are the unique structural components in one asymmetric unit (the unique building block of the entire icosahedron) of the T=16 capsid, which comprises 1 penton (5) subunit, 2½ hexons (P, C, and E), and 5
triplexes (Ta, Tb, Tc, Td, Te, and Tf).