DNA and Chromosomes
Structural and Kinetic Analysis of Nucleoside Triphosphate Incorporation Opposite an Abasic Site by Human Translesion DNA Polymerase η
Background: Abasic sites are the most common lesion in DNA.Results: Kinetic and mass spectrometric assays demonstrate that human polymerase (pol) η preferentially inserts A and G opposite an abasic site.Conclusion: Crystal structures reveal H-bonding between incoming ATP and GTP and the 5′-phosphate of the abasic moiety.Significance: Abasic site bypass by pol η follows a “purine rule” for insertion, with formation of frameshifts.
