【作者】 刘珊珊； 张雯； 明倩倩； 高增强； 侯海峰； 蓝文贤； 董宇辉； 曹春阳；

【Author】 Shanshan Liu1§,Wen Zhang2§,,Zengqiang Gao2,Qianqian Ming1,Haifeng Hou2,Wenxian Lan1,Houming Wu1,Chunyang Cao1,Yuhui Dong2(1.State Key Laboratory of Bio-organic and Natural Product Chemistry,Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,345 Lingling Road,Shanghai 200032,China;2.Beijing Synchrotron Radiation Facility,Institute of High Energy Physics,Chinese Academy of Sciences,19B YuquanLu,Shijingshan District,Beijing 100049,China

【机构】 中国科学院上海有机化学研究所生命有机国家重点实验室； 中国科学院高能物理研究所,北京同步辐射光源；

【摘要】 <正>耐辐射球菌D.radiodurans拥有高效精确的DNA修复系统,这使它可以在强辐射环境下生存。RecQ是D.radiodurans修复系统中重要的DNA修复酶。DrRecQ由Helicase解螺旋区域,RQC区域和3个HRDC区域组成。HRDC1是DrRecQ蛋白N端HRDC结构域的重要组成部分,研究表明,HRDC1在DrRecQ全长蛋白和DNA的结合中发挥了作用。我们更多还原

【Abstract】 The RecQ helicase from Deinococcus radiodurans(DrRecQ) is unusual from other DNA helicases in that it utilizes its three ‘Helicase and RNaseD C-terminal’(HRDC1,2 and 3) domains to regulate its activity.Except its most C-terminal HRDC3 motif,the structures of other HRDC domains were never reported.In this study,we determined the solution structure of the separated and the most N-terminal DrRecQ HRDC1 domain,revealing a globular fold that resembles known DNA binding domains.We thus characterized its DNA-binding activities by fluorescence anisotropy assay,indicating that HRDC1 does not preferentially bind to any DNA substrate,and it is just an auxiliary DNA binding domain of RecQ_Ct domain with weak binding affinities(KD >～10 μM).NMR chemical shift perturbation studies suggested that the key DNA-binding residues of HRDC1 are located in the conserved hydrophobic linker and helices α2,α3 and α5.Finally,the electrostatic surface potentials analysis and NMR binding studies reveal that three HRDC domains of DrRecQ may not interact with each other to achieve their biological functions.更多还原