Description and Procedure:
One of a family of enzymes capable of adding phosphate to its substrate. For Example: polynucleotide kinase (PNK) is an enzyme that catalyzes the transfer of a phosphate from ATP to the 5' end of either DNA or RNA. It is a product of the T4 bacteriophage, and commercial preparations are usually products of the cloned phage gene expressed in E. coli.
Uses or Function:
Transfers phosphate's bond energy to other molecules or may be used to add radioactivity for autoradiography.
Specifically, the polynucleotide kinase (PNK) reaction can provide a radioactive label for a strand of DNA. Polynucleotide kinase transfers the final phosphate group of ATP to a 5'-OH of a DNA (or RNA) strand (as illustrated here.)
Links:
- Kinase Evolution
- Protein Kinase C