3'-PUA termini

FULL NAME: 3'P unsaturated aldehyde termini


DESCRIPTION:
DNA glycosylases/AP lyases initiate repair of oxidized bases in the genomes of all organisms by excising these lesions and then cleaving the DNA strand at the resulting abasic (AP) sites and generate 3' phospho alpha, beta-unsaturated aldehyde (3' PUA) or 3' phosphate (3' P) terminus. In Escherichia coli, the AP-endonucleases (APEs) hydrolyze both 3' blocking groups (3' PUA and 3' P) to generate the 3'-OH termini needed for repair synthesis. In mammalian cells, the previously characterized DNA glycosylases, NTH1 and OGG1, produce 3' PUA, which is removed by the only AP-endonuclease, APE1. However, APE1 is barely active in removing 3' phosphate generated by the recently discovered mammalian DNA glycosylases NEIL1 and NEIL2. 3' phosphate generated by NEIL1 is efficiently removed by polynucleotide kinase (PNK) and not APE1.

DAMAGE TYPE: strand break


DNA DAMAGE SOURCE(S) (MAIN):
cancer chemotherapy
reactive oxygen species (ROS)
repair intermediate


DNA DAMAGE EFFECT(S) (MAIN):
cytotoxic
stalled replication fork


PATHWAYS:
nucleotide incision repair (NIR)
base excision repair (BER)


DNA repair protein(s) related to damage:
XthA (exo III)
Nfo (endo IV)
Fpg (MutM)
Nei (endo VIII)
APTX
APEX1
APEX2


Last modification date: Oct. 10, 2011