Human Dna Cross-Link Repair 1A (Dclre1A. Snm1A); A Target Enabling Package

Cancer cells experience genomic instability, probably through a combination of excessive replicative activity and the loss of function of checkpoint and DNA repair pathways that may have contributed to the oncogenic transformation. Chemotherapy by DNA-damaging agents such as cisplatin and nitrogen mustards create DNA interstrand crosslinks (ICL), which can lead to double-strand breaks and cell death when the cells replicate their DNA. Genotoxic drugs are counteracted by the cell’s DNA damage response. Hence, it is expected that inhibiting DNA repair proteins would sensitise cells to chemotherapy.<br> Here we address an enzyme that participates in the repair of ICLs, DCLRE1A. The TEP includes expression clones and methods for producing the catalytic domain and high-throughput activity assays. Furthermore, we provide a crystallization system that generates thousands of reproducible crystals that allow soaking of small-molecule ligands. We provide crystal structures of several small molecule fragments and inhibitors, opening the way to development of more potent and selective inhibitors.癌细胞会出现基因组不稳定性（genomic instability），这大概率是过度复制活性与细胞检验点（checkpoint）及DNA修复通路（DNA repair pathways）功能丧失共同作用的结果，而上述变化或参与了致癌转化（oncogenic transformation）进程。以顺铂（cisplatin）、氮芥类药物（nitrogen mustards）等DNA损伤剂实施的化疗，可诱导产生DNA链间交联（DNA interstrand crosslinks, ICL）；当细胞进行DNA复制时，这类交联会引发双链断裂（double-strand breaks），最终导致细胞死亡。基因毒性药物（genotoxic drugs）的细胞毒性作用会被自身的DNA损伤应答（DNA damage response）所拮抗。因此，抑制DNA修复蛋白有望使肿瘤细胞对化疗药物更为敏感。 本研究聚焦于一种参与ICL修复的酶——DCLRE1A。本数据集（TEP）包含其表达克隆、催化结构域（catalytic domain）制备方法与高通量活性检测（high-throughput activity assays）方案。此外，我们还提供了一套结晶体系，可制备数千颗可重复的晶体，用于小分子配体（small-molecule ligands）浸泡实验；同时公开了多种小分子片段与抑制剂的晶体结构，为开发更高效、更具选择性的抑制剂奠定了坚实基础。