Role of maturation cleavage in infectivity of picornaviruses: activation of an infectosome

Maturation of picornaviruses involves assembly of a "provirion," which undergoes an autocatalytic cleavage of VP0 to VP2 plus VP4. RNA transcripts from a cDNA clone of human rhinovirus 14 mutated at asparagine 68, one of the residues in the maturation cleavage site, generated normal yields of 150S particles which were noninfectious in the plaque assay because they were unable to initiate a second cycle of infection. These cleavage-defective...