Figure 5.

Comparison of 180- and 120-subunit capsids. (A) Space-filling model of CCMV 180-subunit capsid (7). A, B, and C subunits are blue, red, and green, respectively. One A/B dimer and one C/C dimer are each outlined with a thin white line. One of twelve pentamers of A/B dimers is outlined with a thick white line. The ribbon diagram shows B and C subunits surrounding a threefold axis. Arrowheads illustrate head-to-head CP orientation. (B) Modeled 120-subunit BMV capsid displayed as a space-filling model. A and B subunits are blue and red, respectively. One of twelve pentamers-of-dimers is outlined in white. The upper ribbon diagram illustrates the nearly tail-to-tail interaction of A/B dimers surrounding the threefold axis. The lower ribbon diagram illustrates antiparallel interaction of B subunits between threefold axes. Arrowheads are positioned on subunits as in A.