Three tandem HRDC domains have synergistic effect on the RecQ functions in Deinococcus radiodurans
Three tandem HRDC domains have synergistic effect on the RecQ functions in Deinococcus radiodurans
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DOI：
10.1016/j.dnarep.2006.09.006
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发表时间：
2007-02-04
期刊：
影响因子：
3.8
通讯作者：
Hua, Yuejin
中科院分区：
文献类型：
--
作者：
Huang, Lifen;Hua, Xiaoting;Hua, Yuejin
DNA解旋酶的RecQ家族在维持所有生物体中的基因组稳定性中执行基本功能。在耐辐射球菌中，DR 1289是RecQ家族的一个特殊成员，其C端具有三个串联HRDC结构域的独特排列。dr 1289突变体对γ射线、UV、H2 O2和丝裂霉素C过敏。通过补充的dr 1289突变体与各种域的dr 1289在体内，我们已经确定，解旋酶和所有三个HRDC域是不可缺少的完整的DNA损伤抗性。使用连续荧光染料置换法，我们研究了在各种浓度的ATP和金属离子的Dr 1289解旋功能的最佳条件，以表明解旋酶活性与在大肠杆菌RecQ中观察到的相当。我们还发现解旋酶结构域是解旋和ATP酶活性所必需的，并且三个串联的HRDC结构域增加了这些活性的效率。基于这些数据，我们提出Dr 1289的C-末端在D.抗辐射药物来对抗DNA损伤的类型和数量。(c)2006 Elsevier B. V.保留所有权利。
The RecQ family of DNA helicases performs essential functions in the maintenance of genomic stability in all organisms. in Deinococcus radiodurans, DR1289 is a special member of RecQ family with unique arrangement of three tandem HRDC domains in the C-terminus. A dr1289 mutant is hypersensitive to gamma-irradiation, UV, H2O2 and mitomycin C. By complementing the dr1289 mutant with various domains of Dr1289 in vivo, we have determined that the helicase and all three HRDC domains are indispensable for complete DNA damage resistance. Using a continuous fluorescent dye-displacement assay, we investigated the optimal conditions for Dr1289 unwinding function at various concentrations of ATP and metal ions to show that the helicase activity is comparable to what observed in Escherichia coli RecQ. We also found that the helicase domain is necessary for the unwinding and ATPase activity and that the three tandem HRDC domains increase the efficiency of these activities. Based on these data, we propose that the C-terminus of Dr1289 has evolved in D. radiodurans to confront the types and amounts of DNA damage. (c) 2006 Elsevier B.V. All rights reserved.