文章基本信息

标题：Ribosome reactivates transcription by physically pushing RNA polymerase out of transcription arrest
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作者：Flint Stevenson-Jones ; Jason Woodgate ; Daniel Castro-Roa 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2020
卷号：117
期号：15
页码：8462-8467
DOI：10.1073/pnas.1919985117
出版社：The National Academy of Sciences of the United States of America
摘要：In bacteria, the first two steps of gene expression—transcription and translation—are spatially and temporally coupled. Uncoupling may lead to the arrest of transcription through RNA polymerase backtracking, which interferes with replication forks, leading to DNA double-stranded breaks and genomic instability. How transcription–translation coupling mitigates these conflicts is unknown. Here we show that, unlike replication, translation is not inhibited by arrested transcription elongation complexes. Instead, the translating ribosome actively pushes RNA polymerase out of the backtracked state, thereby reactivating transcription. We show that the distance between the two machineries upon their contact on mRNA is smaller than previously thought, suggesting intimate interactions between them. However, this does not lead to the formation of a stable functional complex between the enzymes, as was once proposed. Our results reveal an active, energy-driven mechanism that reactivates backtracked elongation complexes and thus helps suppress their interference with replication.
关键词：transcription–translation coupling ; RNA polymerase ; ribosome ; backtracking ; conflicts with replication