Models of a fluorescent canine parvovirus virus-like particle. The model was generated from EGFP-VP2-40, showing 15 subunits of the virus-like particle. EGFP emerges from the 5-fold axis and nestles onto the cannon structure. Molecular model (left) and schematic representation (top right) of the EGFP-VP2-40 recombinant capsid structure. EGFP protrudes through the 5-fold axis cannon structures, indicated by white lines, with the central EGFP domain shown in green. Top and side views of a 15 mer region of the capsid model are shown (left and bottom right, respectively). VP2-40 polypeptides belonging to the same trimers that form single facets of the capsid icosahedron are shown in greens, reds, dark blues, yellows and light blues. The EGFP domain is a continuous polypeptide with one of the three VP2-40 domains in each facet of the icosahedral capsid structure, with the EGFP of the other two VP2-40 polypeptides removed by proteolysis before or during capsid assembly. The EGFP domains could be located at all or some of the twelve cannon structures, depending on proteolysis.