GDVII and DA isolates of Theiler's virus: proteins attached to the 5' end of the RNA are bound covalently to the same nucleotides.

GDVII and DA picornaviruses, which represent two biologically distinct subgroups of Theiler's murine encephalomyelitis viruses, were analyzed to detect the presence of a RNA-linked protein, VPg. It was found that the single-stranded RNA genomes isolated from the virions of both viruses contain a protein of approximately 7,000 daltons, which is covalently linked to the 5' end of the RNA. Like in other picornaviruses (e.g., poliovirus and encephalomyocarditis virus), the terminal nucleotide adjacent to the protein was found to be pUp. The possibility that differently charged VPg species exist is also mentioned.