Major component of the virus occlusion bodies which are large proteinaceous structures termed polyhedra. These structures serve as the protective package for the virus particles outside the infected host and allow natural transmission of virus between insect hosts, assisting persistence in the environment. Forms the paracrystalline lattice of polyhedra and interacts with enveloped virions as well as other accessory molecules and structures to form a mature viral occlusion body. Belongs to the polyhedrin family.