Characterization of DNA Substrate Binding to the Phosphatase Domain of the DNA Repair Enzyme Polynucleotide Kinase/Phosphatase.

ABSTRACT: Polynucleotide kinase/phosphatase (PNKP) is a DNA strand break repair enzyme that uses separate 5' kinase and 3' phosphatase active sites to convert damaged 5'-hydroxyl/3'-phosphate strand termini to ligatable 5'-phosphate/3'-hydroxyl ends. The phosphatase active site has received particular attention as a target of inhibition in cancer therapy development. The phosphatase domain dephosphorylates a range of single- and double-stranded substrates; however, structural studies have shown that the phosphatase catalytic cleft can bind only single-stranded substrates. Here we use a catalytically inactive but structurally intact phosphatase mutant to probe interactions between PNKP and a variety of single- and double-stranded DNA substrates using an electrophoretic mobility shift assay. This work

SUBMITTER: Havali-Shahriari Z 

PROVIDER: S-EPMC5469602 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature