Helicase activity and substrate specificity of RecQ5 beta
Helicase activity and substrate specificity of RecQ5 beta
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RecQ5 beta 的解旋酶活性和底物特异性
DOI：
10.1088/1674-1056/26/6/068701
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发表时间：
2017
影响因子：
1.7
通讯作者：
Xi Xu-Guang
中科院分区：
文献类型：
--
作者：
You Jing;Xu Ya-Nan;Li Hui;Lu Xi-Ming;Li Wei;Wang Peng-Ye;Dou Shuo-Xing;Xi Xu-Guang
RecQ 5 β是人体必需的DNA解旋酶，在DNA复制、修复、重组和转录中发挥重要作用。RecQ 5 β的解旋活性和底物特异性仍然难以捉摸。采用停流动力学方法研究了RecQ 5 β与几种DNA底物的解旋和解离动力学，发现RecQ 5 β能很好地解旋ss/dsDNA、叉状DNA和假日连接，但对钝端DNA和G-四链体的解旋能力较差。Rec 5 β对含有连接点的某些DNA底物具有优选的解旋特异性，这可以提高RecQ 5 β的结合亲和力和解旋活性。此外，通过与截短的RecQ 5 β 1− 467的比较，我们发现C端结构域可能强烈影响RecQ 5 β的解旋活性和结合亲和力。这些结果可能有助于阐明RecQ 5 β解旋酶的生理功能和工作机制。（文件）
RecQ5β is an essential DNA helicase in humans, playing important roles in DNA replication, repair, recombination and transcription. The unwinding activity and substrate specificity of RecQ5β is still elusive. Here, we used stopped-flow kinetic method to measure the unwinding and dissociation kinetics of RecQ5β with several kinds of DNA substrates, and found that RecQ5β could well unwind ss/dsDNA, forked DNA and Holiday junction, but was compromised in unwinding blunt DNA and G-quadruplex. Rec5β has the preferred unwinding specificity for certain DNA substrates containing the junction point, which may improve the binding affinity and unwinding activity of RecQ5β. Moreover, from a comparison with the truncated RecQ5 β 1− 467, we discovered that the C-terminal domain might strongly influence the unwinding activity and binding affinity of RecQ5β. These results may shed light on the physiological functions and working mechanisms of RecQ5β helicase.(paper)