Efficient termination of transcription by RNA polymerase I requires a conserved hairpin of the ribosomal RNA precursor

• 全文链接

RNA 聚合酶 I 有效终止转录需要核糖体 RNA 前体的保守发夹

关键词：

来源：

Science Advances

全文链接：

//agri.nais.net.cn/topic/downloadFile/51842c68-6d7b-495c-91ea-5550f9854e72

来源地址：

https://www.science.org/doi/10.1126/sciadv.adw2470

资源所属：

马铃薯基因组设计育种

类型：

学术文献

语种：

英语

原文发布日期：

2025-08-20

摘要：

RNA polymerase I (Pol I) synthesizes ribosomal RNA precursor (pre-rRNA), which comprises most of RNA in eukaryotic cells. Despite decades of investigation, there is still no consensus on what causes Pol I transcription termination. Here, we show that efficient termination by Pol I, paused by termination roadblock protein, is caused by RNA hairpin of the nascent pre-rRNA. Hairpin-dependent termination takes place at a physiological rate and does not require trans-acting factors. The function of the roadblock protein and the T-rich sequence is to synergistically cause deep backtracking of Pol I toward the termination RNA hairpin. Simultaneously, Pol I is catalytically inactivated, preventing rescue from backtracking through RNA cleavage and thus committing Pol I to termination. Termination RNA hairpins are present in most of Pol I terminators of eukaryotes, suggesting conservation of the RNA hairpin–dependent mechanism of Pol I transcription termination. We propose a simple model that unifies previous findings.