Hierarchical structure assembly model of rice dwarf virus particle formation.

Rice dwarf virus (RDV) of the family Reoviridae and genus Phytoreovirus, is the cause of rice dwarf disease, a major negative effector of rice production throughout East Asia, including Japan. RDV has an icosahedral double-layered shell of approximately 70 nm diameter. The structural proteins constituting the capsid can self-assemble into a correct particle without requiring the help of any external factors in vitro. A total of more than 900 components assemble to make the full particle. A series of structural and functional studies of RDV, including X-ray crystallography and cryo-electron microscopy, suggest a hierarchical self-assembly mechanism involving both homologous and heterologous interactions. As such, systems for the recognition of each component should be essential for particle formation.