FIG 5.

BtAdV 250-A has a capsid morphology similar to CAdV-2 and a prominent protein IX extending from its surface. (A) The surface-rendered maps of BtAdV 250-A, CAdV A (serotype CAdV-2) (EMDB 1462), and Human mastadenovirus C (HAdV C; serotype HAdV-5) (EMDB 5172) are colored according to radius (key) to illustrate similar topologies. In addition to the radial coloring, protein IX was highlighted in crimson in BtAdV and CAdV to demonstrate its location and prominence in the capsid. Note that protein IX in BtAdV protrudes well beyond the hexon proteins. (B) Magnification of the icosahedral 5-fold vertex of BtAdV. The five peripentonal hexons (purple), which surround a single tulip-shaped penton base (green) with its central projecting fiber stalk (royal blue), are visible. The C-terminal surface exposed spikes of two protein IX triskelions (crimson) are shown on the left. (C) The central section of the superimposed structures of BtAdV 250-A (light blue) and CAdV-2 (dark blue) reveal overlapping internal structural similarities between the viruses.