title: An enzymatic activity in uninfected cells that cleaves the linkage between poliovirion RNA and the 5' terminal protein.
abstract: The 5' terminal protein (VPg) on poliovirion RNA can be removed by cell-free extracts from a variety of uninfected cells. This soluble enzymatic activity is found in both nuclear and cytoplasmic extracts of heLa cells and is activated by Mg++. The enzyme activity cleaves the tyrosine-phosphate bond that links the protein to the RNA. In a partially purified form it has insufficient nonspecific protease or nuclease activity to account for its action. The existence of this enzyme implies that poliovirus RNA is translated in cell-free extracts in a form that lacks the 5' terminal protein. The role of this enzyme in the uninfected cell is not known.
mesh_terms: D001483:Base Sequence; D002413:Cations, Divalent / Q000494:pharmacology; D002467:Cell Nucleus / Q000201:enzymology; D006367:HeLa Cells / Q000201:enzymology; D006358:Hot Temperature; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D017955:Poliovirus / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism*; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D002413:Cations, Divalent; D012333:RNA, Messenger; D012367:RNA, Viral; D014764:Viral Proteins; D010744:Phosphoric Monoester Hydrolases