Non-enveloped, spherical, capsid of about 35 nm with T=3 icosahedral symmetry. Surface projections are small and surface appears rough, spikes protruding from the 30 vertices.
The capsid precursor protein (180 copies per particle) undergoes
C-terminal cleavages by host caspases during virus maturation. Infectious particles are generated by further cleavages of VP70 by extracellular proteases resulting in three structural proteins