The members of this family are derived from nepoviruses. Together with comoviruses and picornaviruses, nepoviruses are classified in the picornavirus superfamily of plus strand single-stranded RNA viruses. This family aligns several nepovirus coat protein sequences. In several cases, this is found at the C-terminus of the RNA2-encoded viral polyprotein. The coat protein consists of three trapezoid-shaped beta-barrel domains, and forms a pseudo T = 3 icosahedral capsid structure.