title: Covalent linkage of a protein to a defined nucleotide sequence at the 5'-terminus of virion and replicative intermediate RNAs of poliovirus.
abstract: The 5'-terminus of poliovirus polyribosomal RNA is pUp. A candidate for the 5'-terminus of poliovirion RNA was recovered as a compound migrating toward the cathode when 32P-labeled virion RNA was completely digested with ribonucleases T1, T2 and A and analyzed by paper ionophoresis at pH 3.5. Treatment with proteinase K reversed its direction of migration, indicating the presence of protein. Treatment with venom phosphodiesterase liberated all of the radioactivity as pUp, suggesting that poliovirion RNA has a protein-pUp 5'-terminus. Treatment of virion RNA with T1 ribonuclease alone generated a proteinase K-sensitive oligoribonucleotide. Analysis of the oligoribonucleotide using ribonucleases A and U2 showed its structure to be protein-pU-U-A-A-A-A-C-A-G. Digests of replicative intermediate RNA contained sufficient protein-pUp to suggest that this structure is at the 5'-end of most nascent poliovirus RNA molecules. We suggest that a protein-nucleotide structure acts as a primer for initiating synthesis of poliovirus RNA.
mesh_terms: D001483:Base Sequence; D009843:Oligoribonucleotides / Q000032:analysis; D017955:Poliovirus / Q000032:analysis* / Q000378:metabolism; D012367:RNA, Viral / Q000096:biosynthesis; D012261:Ribonucleoproteins / Q000032:analysis; D014764:Viral Proteins; D014779:Virus Replication
chemical_list: D009843:Oligoribonucleotides; D012367:RNA, Viral; D012261:Ribonucleoproteins; D014764:Viral Proteins