Major tegument protein that participates in the egress of nucleocapsids from the host nucleus. May be involved in host nucleus-cytoplasm transportation of nucleocapsids to form budded virion (BVs). Homooligomer. Homotrimer. Forms oligomers in infected cells, while selectively assembles as trimers into progeny virions. Localizes in both the budded virions (BVs) and occlusion-derived virions (ODVs) but amount in BVs is much lower than that in ODVs. Associated with the polyhedron-derived virus (occluded virus). O-glycosylated; by N-acetylglucosamine at one or more locations. Belongs to the baculoviridae gp41 family.