Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.64 (proteinase K)
 4,071 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
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PMID:Covalent linkage of a protein to a defined nucleotide sequence at the 5'-terminus of virion and replicative intermediate RNAs of poliovirus. 19 41

UV-induced cyclobutane dimers and 6-4 photoproducts, containing an unmodified nucleotide at the 5'-position were released from DNA by means of digestion with DNase I, snake venom phosphodiesterase and prostatic acid phosphatase. The enzymes were deactivated by proteinase K followed by ethanol precipitation. The products were phosphorylated by polynucleotide kinase and [gamma-32P]ATP. The TLC system used for the analysis enables separation of the different photoproducts and detection at a fmol level. T4 endonuclease treatment was applied to confirm the positions of cyclobutane dimers.
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PMID:Analysis of UV-induced DNA photoproducts by 32P-postlabelling. 783 95