Forms an icosahedral capsid of pseudo T=3 symmetry with capsid proteins VP2 and VP3. Together they form an icosahedral capsid composed of 60 copies of each VP1, VP2, and VP3, with a diameter of approximately 300 Angstroms.VP4 lies on the inner surface of the protein shell formed by VP1, VP2 and VP3. All the three latter proteins contain a beta-sheet structure called beta-barrel jelly roll. VP1 is situated at the 12 fivefold axes, whereas VP2 and VP3 are located at the quasi-sixfold axes