The small non-structural protein NS2 of the autonomous parvovirus minute virus of mice is required for virus growth in murine cells.

Mutants of the autonomous parvovirus minute virus of mice (MVM) strains MVM(p) and MVM(i) that either fail to produce or produce a truncated NS2 protein, were deficient in the production of infectious virus and attained lower levels of viral DNA synthesis than wild-type virus following infection of a series of normal and transformed murine cell lines. Mutant virus growth and the levels of DNA replication were similar to those of wild-type virus in the rat, hamster and human lines tested. These results suggest that the requirement of NS2 for the growth of MVM is murine species-specific.