Why large icosahedral viruses need scaffolding proteins

摘要: While small single-stranded viral shells encapsidate their genome spontaneously, many large viruses, such as the herpes simplex virus or infectious bursal disease (IBDV), typically require a template, consisting of either scaffolding proteins an inner core. Despite proliferation viruses in nature, mechanisms by which hundreds thousands assemble to form structures with icosahedral order (IO) is completely unknown. Using continuum elasticity theory, we study growth (capsids) and show that nonspecific template not only selects radius capsid, but also leads error-free assembly protein subunits into capsids universal IO. We prove spherical cap grows, there deep potential well at locations disclinations later process will become vertices icosahedron. Furthermore, introduce minimal model simulate shell around under nonequilibrium conditions find perfect match between results theory numerical simulations. Besides explaining available experimental results, provide number predictions. Implications for other problems crystals are discussed.