In enzymology, a polynucleotide 5'-hydroxyl-kinase () is an enzyme that catalyzes the chemical reaction
ATP + 5'-dephospho-DNA ADP + 5'-phospho-DNA
Thus, the two substrates of this enzyme are ATP and 5'-dephospho-DNA, whereas its two products are ADP and 5'-phospho-DNA. Polynucleotide kinase is a T7 bacteriophage (or T4 bacteriophage) enzyme that catalyzes the transfer of a gamma-phosphate from ATP to the free hydroxyl end of the 5' DNA or RNA. The resulting product could be used to end-label DNA or RNA, or in ligation reactions.
Nomenclature
This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups (phosphotransferases) with an alcohol group as an acceptor. The systematic name of this enzyme class is ATP:5'-dephosphopolynucleotide 5'-phosphotransferase. Other names in common use include: ATP:5'-dephosphopolynucleotide 5'-phosphatase PNK polynucleotide 5'-hydroxyl kinase (phosphorylating), 5'-hydroxyl polynucleotide kinase, 5'-hydroxyl polyribonucleotide kinase, 5'-hydroxyl RNA kinase, DNA 5'-hydroxyl kinase, DNA kinase, polynucleotide kinase, and polynucleotide 5'-hydroxy-kinase.
References
External links Vivo New England Biolabs' T4 PNK page