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English: Schematic planar diagram of the Invertebrate iridescent virus 6 (IIV-6, genus Iridovirus) capsid structure with the central pentamer complex (white pentagon) omitted for clarity. The centrally located white ellipse, triangle and pentagon symbols highlight the positions of 2-, 3-, and 5-fold icosahedral axes, respectively. All major capsid protein trimers are shown as three small grey disks enclosed by a hexagon. The icosahedral asymmetric unit contains 24 and one-third of these capsomers (numbered 1–25). Each trisymmetron contains 55 capsomers, all oriented similarly and rotated by 60° relative to those in the adjacent trisymmetron. Finger proteins bind to each trisymmetron (nine within one asymmetric unit are numbered in white), a total of 27 in each trisymmetron. A total of 18 Zip dimers are present at the interface between one trisymmetron and its adjacent trisymmetrons. Zip monomers are located at the interface between a trisymmetron and its neighbouring pentasymmetrons. The transmembrane anchor proteins (shown in Figure 2G) are located under capsomers 2 and 3 beneath the pentasymmetron. (From Yan et al. (2009). J. Mol. Biol., 385, 1287–1299; with permission.)