Drag on the model to rotate it.
The model on the right* is based on the crystallographic solution of the VP1 capsid protein published in 1SVA.
The atomic coordinate file 1SVA contains a pentamer of the VP1 protein (plus one extra chain). The entire capsid was constructed from 1SVA by the Probable Quaternary Structure server (of the European Bioinformatics Institute) using symmetry operations specified in 1SVA. The resulting capsid model contains 360 chains of VP1 protein arranged as 72 pentamers in an icosahedron (12 faces). The PDB atomic coordinate file for the capsid, containing all non-hydrogen protein atoms, is 70 megabytes in size.
For the model at the right, each protein chain was reduced to a single atom (resulting in 360 atoms). The distances between atoms were then greatly reduced to enable Chime to display the model at right with overlapping "atomic" spheres to simulate the capsid.
Pentamers representing the vertices that define the 12 faces of the icosahedron are colored yellow. Pseudoatoms were placed over each vertex to enable drawing lines representing the orientation of the icosahedron.
For more information, see SV40 in the Atlas of Macromolecules.