5'-Hydroxyl polyribonucleotide kinase from HeLa cell nuclei. Purification and properties.
An enzyme, 5'-hydroxyl polyribonucleotide kinase, which catalyzes the phosphorylation of 5'-hydroxyl ends of RNA in the presence of ATP, has been isolated from extracts of HeLa cell nuclei. The kinase requires a divalent cation (Mg2+ or Mn2+) for activity, has an alkaline pH optimum, and is sensitive to the sulfhydryl antagonist N-ethylmaleimide. 5'-hydroxyl terminated polydeoxyribonucleotides are phosphorylated much less efficiently than the 5'-hydroxyl terminated polyribonucleotides, and the kinase preparation is inactive on ribonucleoside 3'-monophosphates. Enzyme activity is inhibited by ADP and by pyrophosphate. The sedimentation coefficient of the kinase is estimated to be 5.6 S from glycerol gradient centrifugation.
D002413:Cations, Divalent; D002467:Cell Nucleus / Q000201:enzymology*; D005260:Female; D006367:HeLa Cells / Q000201:enzymology*; D006801:Humans; D007700:Kinetics; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism*; D011116:Polynucleotide 5'-Hydroxyl-Kinase / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity
D002413:Cations, Divalent; D010770:Phosphotransferases; D011116:Polynucleotide 5'-Hydroxyl-Kinase