Rachel Bezalel-Buch, Young K Cheun, Upasana Roy, Orlando D Schärer, Peter M Burgers
Nucleic acids research 2020 Sep 04DNA polymerase ζ (Pol ζ) and Rev1 are essential for the repair of DNA interstrand crosslink (ICL) damage. We have used yeast DNA polymerases η, ζ and Rev1 to study translesion synthesis (TLS) past a nitrogen mustard-based interstrand crosslink (ICL) with an 8-atom linker between the crosslinked bases. The Rev1-Pol ζ complex was most efficient in complete bypass synthesis, by 2-3 fold, compared to Pol ζ alone or Pol η. Rev1 protein, but not its catalytic activity, was required for efficient TLS. A dCMP residue was faithfully inserted across the ICL-G by Pol η, Pol ζ, and Rev1-Pol ζ. Rev1-Pol ζ, and particularly Pol ζ alone showed a tendency to stall before the ICL, whereas Pol η stalled just after insertion across the ICL. The stalling of Pol η directly past the ICL is attributed to its autoinhibitory activity, caused by elongation of the short ICL-unhooked oligonucleotide (a six-mer in our study) by Pol η providing a barrier to further elongation of the correct primer. No stalling by Rev1-Pol ζ directly past the ICL was observed, suggesting that the proposed function of Pol ζ as an extender DNA polymerase is also required for ICL repair. © The Author(s) 2020. Published by Oxford University Press on behalf of Nucleic Acids Research.
Rachel Bezalel-Buch, Young K Cheun, Upasana Roy, Orlando D Schärer, Peter M Burgers. Bypass of DNA interstrand crosslinks by a Rev1-DNA polymerase ζ complex. Nucleic acids research. 2020 Sep 04;48(15):8461-8473
PMID: 32633759
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