Self-assembles to form the virion icosahedral capsid with a T=1 symmetry. This very small capsid (17 - 22 nm in diameter) allows the virus to be very stable in the environment and resistant to some disinfectants, including detergents. Essential for the initial attachment to heparan sulfate moities and chondroitin sulfate B of the host cell surface proteoglycans. After attachment, the virus is internalized in a clathrin-, caveolae- and dynamin-independent, actin and Rho-GTPase-mediated pathway and traffics to the nucleus. The capsid protein binds and transports the viral genome and Rep across the nuclear envelope.