Direct Restart of a Replication Fork Stalled by a Head-On RNA Polymerase
Direct Restart of a Replication Fork Stalled by a Head-On RNA Polymerase
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DOI：
10.1126/science.1179595
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发表时间：
2010-01-29
期刊：
影响因子：
56.9
通讯作者：
O'Donnell, Mike
中科院分区：
文献类型：
--
作者：
Pomerantz, Richard T.;O'Donnell, Mike
在体内的研究表明，复制叉被逮捕遇到迎面转录复合物。然而，复制体和RNA聚合酶（RNAP）在正面碰撞后的命运是未知的。我们发现大肠杆菌复制体在与正面转录复合体碰撞时会停滞，但复制叉并没有崩溃，而是保持高度稳定，并最终在取代DNA中的RNAP后恢复伸长。我们还发现，转录修复偶联因子Mfd促进碰撞后的直接重新启动的叉子，促进位移的RNAP。这些发现表明了复制装置的内在稳定性和转录偶联修复途径在促进复制通过RNAP阻断中的先前未知作用。
In vivo studies suggest that replication forks are arrested by encounters with head-on transcription complexes. Yet, the fate of the replisome and RNA polymerase (RNAP) after a head-on collision is unknown. We found that the Escherichia coli replisome stalls upon collision with a head-on transcription complex, but instead of collapsing, the replication fork remains highly stable and eventually resumes elongation after displacing the RNAP from DNA. We also found that the transcription-repair coupling factor Mfd promotes direct restart of the fork after the collision by facilitating displacement of the RNAP. These findings demonstrate the intrinsic stability of the replication apparatus and a previously unknown role for the transcription-coupled repair pathway in promoting replication past a RNAP block.