Cellular processes, such as DNA replication, recombination and transcription, require DNA strands separation and single-stranded DNA is formation. The single-stranded DNA is promptly wrapped by human single-stranded DNA binding proteins, replication protein A (RPA) complex. RPA binding not only prevent nuclease degradation and annealing, but it also coordinates cell-cycle checkpoint activation and DNA repair. However, RPA binding offers little protection against the chemical modification of DNA bases. This review focuses on the type of DNA base damage that occurs in single-stranded DNA and how the damage is rectified in human cells. The discovery of DNA repair proteins, such as ALKBH3, AGT, UNG2, NEIL3, being able to repair the damaged base in the single-stranded DNA, renewed the interest to study single-stranded DNA repair. These mechanistically different proteins work independently from each other with the overarching goal of increasing fidelity of recombination and promoting error-free replication.

中文翻译：

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单链DNA损伤：保护单链DNA免受化学攻击。

细胞过程，例如DNA复制，重组和转录，需要DNA链分离，并形成单链DNA。单链DNA立即被人单链DNA结合蛋白，复制蛋白A（RPA）复合物包裹。RPA结合不仅可以防止核酸酶降解和退火，而且还可以协调细胞周期检查点激活和DNA修复。但是，RPA结合几乎不能保护DNA碱基的化学修饰。这篇综述着重于单链DNA中发生的DNA碱基损伤的类型以及在人细胞中如何修复该损伤。DNA修复蛋白如ALKBH3，AGT，UNG2，NEIL3的发现，能够修复单链DNA中受损的碱基，重新引起了人们对研究单链DNA修复的兴趣。