Helicase promotes replication re-initiation from an RNA transcript.
Helicase promotes replication re-initiation from an RNA transcript.
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DOI：
10.1038/s41467-018-04702-x
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发表时间：
2018-06-13
影响因子：
16.6
通讯作者：
Wang MD
中科院分区：
文献类型：
--
作者：
Sun B;Singh A;Sultana S;Inman JT;Patel SS;Wang MD
为了确保准确的DNA复制，一个复制体必须有效地克服其DNA底物上的许多障碍。在遇到障碍后，正在进行的复制体通常会中止DNA合成，但会继续展开。然而，对于DNA合成如何在障碍的下游恢复，人们知之甚少。在这里，我们研究了非复制复制体与共向RNA聚合酶（RNAP）碰撞的后果。使用单分子和集成方法，我们发现T7解旋酶与复制叉上的非复制T7 DNA聚合酶（DNAP）强烈相互作用。随着解旋酶的前进，相关的DNAP也向前移动。DNAP的存在增加了解旋酶的加工性和解绕率。我们发现，这样的dna及其解旋酶确实能够主动破坏停滞的转录延伸复合体，然后使用RNA转录物作为引物启动复制。这些观察结果显示了T7解旋酶在复制再起始中的新作用。在DNA复制过程中，复制解旋酶对DNA解绕起着至关重要的作用。在这里，作者发现噬菌体T7解旋酶也通过与非复制的dna相互作用和增加解绕速率参与复制重新启动。
To ensure accurate DNA replication, a replisome must effectively overcome numerous obstacles on its DNA substrate. After encountering an obstacle, a progressing replisome often aborts DNA synthesis but continues to unwind. However, little is known about how DNA synthesis is resumed downstream of an obstacle. Here, we examine the consequences of a non-replicating replisome collision with a co-directional RNA polymerase (RNAP). Using single-molecule and ensemble methods, we find that T7 helicase interacts strongly with a non-replicating T7 DNA polymerase (DNAP) at a replication fork. As the helicase advances, the associated DNAP also moves forward. The presence of the DNAP increases both helicase’s processivity and unwinding rate. We show that such a DNAP, together with its helicase, is indeed able to actively disrupt a stalled transcription elongation complex, and then initiates replication using the RNA transcript as a primer. These observations exhibit T7 helicase’s novel role in replication re-initiation. During DNA replication, replicative helicases play an essential role for DNA unwinding to occur. Here the authors find that bacteriophage T7 helicase is also involved in replication re-initiation by interacting with a non-replicating DNAP and increasing unwinding rate.
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DOI：
10.1126/science.1225437
发表时间：
2012-11-30
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Manosas M;Perumal SK;Croquette V;Benkovic SJ
通讯作者：
Benkovic SJ
影响因子：
64.8
作者：
Cox, MM;Goodman, MF;Marians, KJ
通讯作者：
Marians, KJ
影响因子：
2.9
作者：
Jia, YP;Patel, SS
通讯作者：
Patel, SS
影响因子：
4.8
作者：
Kulczyk, Arkadiusz W.;Akabayov, Barak;Richardson, Charles C.
通讯作者：
Richardson, Charles C.
影响因子：
16
作者：
Duderstadt, Karl E.;Geertsema, Hylkje J.;van Oijen, Antoine M.
通讯作者：
van Oijen, Antoine M.