Schematic representation of the T=3, truncated icosahedron (left) and a surface representation of the CMV capsid colored according to radial distance (right). In the schematic, the labeled A, B, and C subunits are those that are in the general orientation used for the following diagrams. The subunits used to represent the icosahedral asymmetric unit were chosen to demonstrate the quasi-sixfold axis and are not related by a quasi-threefold axis. In both images the icosahedral threefold (quasi-sixfold [Q6]), fivefold, twofold, and the quasi-threefold (Q3) axes are labeled. In the schematic, six white circles are positioned around one of the quasi-sixfold axes to approximate the location of the hexameric bundle of N-terminal helices described in the following figures.