Fusolin is a protein found in spindles of insect poxviruses that resembles the lytic polysaccharide monooxygenases of chitinovorous bacteria and may function to disrupt the chitin-rich peritrophic matrix that protects insects against oral infections. Thus, it is a component of the virus occlusion bodies (which are large proteinaceous polyhedra) that protect the virus from the outside environment for extended periods until they are ingested by insect larvae.
Jiyao W et al.(2023). "The conserved domain database in 2023.",