Encephalomyocarditis virus RNA synthesis in vitro is protein-primed

A crude membrane-bound replication complex isolated from encephalomyocarditis virus-infected cells is able to initiate the synthesis of viral RNA. Both the formation of the primer, VPg-pU, and its utilization for the initiation of RNA chains take place in this system. A significant amount of the synthesized VPg-pU is found in the free form. The predominant product of the de novo initiation is represented by short phenol-soluble VPg oligonucleotide species, and only a small percentage of the latter appear to be elongated into longer RNA chains.