The genome-linked protein and 5' end RNA sequence of plum pox potyvirus

The infectivity of plum pox potyvirus (PPV) RNA was decreased by treatment with proteases. Ribonuclease digestion of iodinated PPV RNA yielded material which had an electrophoretic mobility corresponding to Mr 22,000. This protein presumably corresponds to the protease-sensitive structure needed for infectivity. A protein-linked RNase T1-resistant oligonucleotide, 38 nucleotides long, was sequenced and shown to correspond to the 5' terminus of the RNA by sequence comparison to the RNAs of two other potyviruses, tobacco etch virus and tobacco vein mottling virus. A 12 nucleotide block was found to be completely conserved in the RNAs of the three viruses.