Reaction: PNKP hydrolyzes the terminal 3'Pi at the NEIL1,NEIL2-generated single strand break (SSB)
- in pathway: APEX1-Independent Resolution of AP Sites via the Single Nucleotide Replacement Pathway
PNKP, a bifunctional polynucleotide phosphatase/kinase, acts as a 3' phosphatase to remove the terminal 3' phosphate group (3'Pi) at the single strand break (SSB) generated by NEIL1 or NEIL2 beta/delta lyase activity. The presence of XRCC1 is necessary for the 3'-phosphatase activity of PNKP. The removal of the 3'Pi (generating a 3'-OH) makes the DNA with the 3'-end suitable for extension by the DNA polymerase beta (POLB) (Whitehouse et al. 2001, Wiederhold et al. 2004, Das et al. 2006).
Reaction - small molecule participants:
Pi [nucleoplasm]
H2O [nucleoplasm]
Reactome.org reaction link: R-HSA-5649705
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Reaction input - small molecules:
water
Reaction output - small molecules:
hydrogenphosphate
Reactome.org link: R-HSA-5649705