The genome-linked protein of picornaviruses. VIII. Complete amino acid sequence of poliovirus VPg and carboxy-terminal analysis of its precursor, P3-9.
VPg, the genome-linked protein of poliovirus, and its putative precursor P3-9, were radiolabelled and subjected to carboxypeptidase-A digestion. The release of amino acids was followed by identification and quantification on an amino acid analyser. Both proteins were found to be co-terminal with a sequence of -valyl-glutamine-COOH, an observation that provides further evidence that host cell trimming of virus-specific peptides does not play a role in poliovirus protein processing. Radiolabelled VPg was subjected to automated Edman degradation. The combined results complete the structural analysis of VPg, a polypeptide 22 amino acids in length with a molecular weight of 2354. Only one form of VPg has been found linked to virion RNA and it originates by a cleavage at glutaminyl-glycine pairs at both termini. The observation is consistent with other cleavages found in the virus processing scheme.
D000595:Amino Acid Sequence; D005814:Genes, Viral; D017955:Poliovirus / Q000235:genetics*; D011498:Protein Precursors / Q000032:analysis*; D014758:Viral Core Proteins; D014764:Viral Proteins / Q000032:analysis*
D011498:Protein Precursors; D014758:Viral Core Proteins; D014764:Viral Proteins