School of Public Health & Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Zhejiang, China.
Elife. 2023 Sep 5;12:e81639. doi: 10.7554/eLife.81639.
The heterotrimeric Replication protein A (RPA) is the ubiquitous eukaryotic single-stranded DNA (ssDNA) binding protein and participates in nearly all aspects of DNA metabolism, especially DNA damage response. The N-terminal OB domain of the RPA70 subunit (RPA70N) is a major protein-protein interaction element for RPA and binds to more than 20 partner proteins. Previous crystallography studies of RPA70N with p53, DNA2 and PrimPol fragments revealed that RPA70N binds to amphipathic peptides that mimic ssDNA. NMR chemical-shift studies also provided valuable information on the interaction of RPA70N residues with target sequences. However, it is still unclear how RPA70N recognizes and distinguishes such a diverse group of target proteins. Here, we present high-resolution crystal structures of RPA70N in complex with peptides from eight DNA damage response proteins. The structures show that, in addition to the ssDNA mimicry mode of interaction, RPA70N employs multiple ways to bind its partners. Our results advance the mechanistic understanding of RPA70N-mediated recruitment of DNA damage response proteins.
异源三聚体复制蛋白 A（RPA）是普遍存在的真核细胞单链 DNA（ssDNA）结合蛋白，参与 DNA 代谢的几乎所有方面，特别是 DNA 损伤反应。RPA70 亚基（RPA70N）的 N 端 OB 结构域是 RPA 的主要蛋白-蛋白相互作用元件，与超过 20 个伴侣蛋白结合。先前的 RPA70N 与 p53、DNA2 和 PrimPol 片段的晶体学研究表明，RPA70N 结合模拟 ssDNA 的两亲肽。NMR 化学位移研究也为 RPA70N 残基与靶序列的相互作用提供了有价值的信息。然而，目前尚不清楚 RPA70N 如何识别和区分如此多样化的靶蛋白。在这里，我们展示了 RPA70N 与来自 8 种 DNA 损伤反应蛋白的肽复合物的高分辨率晶体结构。这些结构表明，除了 ssDNA 模拟相互作用模式外，RPA70N 还采用多种方式与其伴侣结合。我们的结果推进了对 RPA70N 介导的 DNA 损伤反应蛋白募集的机制理解。
