Holliday junction（HJ）是DNA重组修复过程中标志性中间产物，细胞必须对其进行正确加工才能完成染色体的正常复制，保证细胞的存活。HJ解离酶是HJ加工途径中的关键酶，其参与的途径是HJ加工的主要途径之一。细菌中的HJ解离酶RuvC在解旋酶RuvA和RuvB复合体对HJ进行迁移之后对HJ进行解离。近年来古菌和真核生物中也相继发现了HJ解离酶，但其在细胞内的详细作用和调控机制还不十分清楚。本项目拟利用遗传学和转录组学方法，构建基因缺失及回补菌株，检测单基因缺失或与其它结构特异性核酸内切酶基因共缺失对DNA损伤敏感性的影响及引起的转录组变化，分析Hje在DNA损伤修复中的作用及其与这些结构特异性核酸酶的遗传关系。利用亲和纯化和质谱分析方法分离可能与解离酶Hje相互作用的蛋白，鉴定相互作用蛋白的性质和互作机制。预期将揭示和了解古菌解离酶在DNA修复中的作用和新的调控机制。

Holliday junction（HJ）is the hallmarker DNA intermediate of DNA recombinational repair. Cells must process the intermediate properly to fullfill normal chromosomal replication and survive. HJ resolvase is one of the key enzymes and the pathway involved is one of the main pathways processing HJ intermediates. The bacterial resolvase RuvC cleaves HJ　after it is migrated by the complex formed by the helicases RuvA and RuvB. In recent years, resolvases from archaea and eukarya have been identified. However, their detailed cellular functions and mechanisms are still unclear. In this study, we will construct stains of sigle or double deletion of hje, xpf, and others which encode structure-specific endonucleases and the overexpression strains, detect the sensitivity of these strains to DNA damage agents, and analyze the changes in transcription levels in order to deduce the role of Hje and its relationship with the structure-specific endonucleases. We will attempt to purify and characterize proteins that putatively interact with the resolvase by means of affinity purification and mass spectrometry. It is expected that the in vivo functions and a novel regulatory mechanisms of the resolvase will be revealed.