T4 Polynucleotide Kinase (NEB #M0201) can be used to 5' end label DNA and RNA because it catalyzes the transfer and exchange of phosphate from ATP to the 5´ -hydroxyl terminus of polynucleotides (double-and single-stranded DNA and RNA) and nucleoside 3´-monophosphates. Polynucleotide Kinase also catalyzes the removal of 3´-phosphoryl groups from 3´-phosphoryl polynucleotides, deoxynucleoside 3´-monophosphates and deoxynucleoside 3´-diphosphates (1).
T4 Polynucleotide Kinase (3' phosphatase minus) (NEB #M0236) is a modified version that exhibits full kinase activity with no 3´ phosphatase activity (2,3).
NEBCloner is a guide for selecting appropriate products and viewing protocols for steps in the cloning workflow. To help select the right kinase, choose "End Modification" on the tool to start.
Phosphorylation is the process by which phosphate groups are added to a molecule by a kinase. The phosphorylation status of a fragment of DNA can influence its ability to proceed in reactions. Learn more about phosphorylation and kinases.