DNA 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.

中文翻译：

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Rev1-DNA聚合酶ζ复合物绕过DNA链间交联。

DNA 聚合酶 ζ (Pol ζ) 和 Rev1 对于修复 DNA 链间交联 (ICL) 损伤至关重要。我们使用酵母 DNA 聚合酶 η、ζ 和 Rev1 来研究跨损伤合成 (TLS)，通过基于氮芥的链间交联 (ICL)，在交联碱基之间有一个 8 原子接头。与单独的 Pol ζ 或 Pol η 相比，Rev1-Pol ζ 复合物在完全旁路合成中最有效，效率提高了 2-3 倍。高效 TLS 需要 Rev1 蛋白，但不需要其催化活性。一个 dCMP 残基被 Pol η、Pol ζ 和 Rev1–Pol ζ 忠实地插入到 ICL-G 中。Rev1–Pol ζ，尤其是单独的 Pol ζ 显示出在 ICL 之前停止的趋势，而 Pol η 在插入 ICL 之后就停止了。Pol η 直接通过 ICL 的停滞归因于其自身抑制活性，由 Pol η 延长 ICL 未钩住的短寡核苷酸（我们研究中的六聚体）引起的，这为正确引物的进一步延长提供了障碍。没有观察到 Rev1-Pol ζ 直接越过 ICL，这表明 Pol ζ 作为延伸 DNA 聚合酶的拟议功能也是 ICL 修复所必需的。