气候变化领域集成服务门户(CCPortal): Structural origins of Escherichia coli RNA polymerase open promoter complex stability

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DOI	10.1073/pnas.2112877118
	Structural origins of Escherichia coli RNA polymerase open promoter complex stability
	Saecker R.M.; Chen J.; Chiu C.E.; Malone B.; Sotiris J.; Ebrahim M.; Yen L.Y.; Eng E.T.; Darst S.A.
发表日期	2021
ISSN	0027-8424
卷号	118 期号:40
英文摘要	The first step in gene expression in all organisms requires opening the DNA duplex to expose one strand for templated RNA synthesis. In Escherichia coli, promoter DNA sequence fundamentally determines how fast the RNA polymerase (RNAP) forms “open” complexes (RPo), whether RPo persists for seconds or hours, and how quickly RNAP transitions from initiation to elongation. These rates control promoter strength in vivo, but their structural origins remain largely unknown. Here, we use cryoelectron microscopy to determine the structures of RPo formed de novo at three promoters with widely differing lifetimes at 37 °C: λPR (t1/2 ∼10 h), T7A1 (t1/2 ∼4 min), and a point mutant in λPR (λPR-5C) (t1/2 ∼2 h). Two distinct RPo conformers are populated at λPR, likely representing productive and unproductive forms of RPo observed in solution studies. We find that changes in the sequence and length of DNA in the transcription bubble just upstream of the start site (+1) globally alter the network of DNA–RNAP interactions, base stacking, and strand order in the single-stranded DNA of the transcription bubble; these differences propagate beyond the bubble to upstream and downstream DNA. After expanding the transcription bubble by one base (T7A1), the nontemplate strand “scrunches” inside the active site cleft; the template strand bulges outside the cleft at the upstream edge of the bubble. The structures illustrate how limited sequence changes trigger global alterations in the transcription bubble that modulate the RPo lifetime and affect the subsequent steps of the transcription cycle. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Cryo-EM; Open complex; Promoter DNA; RNA polymerase; Transcription
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/238787
作者单位	Laboratory of Molecular Biophysics, Rockefeller University, New York, NY 10065, United States; Evelyn Gruss Lipper Cryo-Electron Microscopy Resource Center, Rockefeller University, New York, NY 10065, United States; National Resource of Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, United States; Department of Cell Biology, New York University, Grossman School of Medicine, New York, NY 10016, United States; Department of Physiology and Cellular Biophysics, Columbia University Vagelos College of Physicians and Surgeons, New York, NY 10032, United States
推荐引用方式 GB/T 7714	Saecker R.M.,Chen J.,Chiu C.E.,et al. Structural origins of Escherichia coli RNA polymerase open promoter complex stability[J],2021,118(40).
APA	Saecker R.M..,Chen J..,Chiu C.E..,Malone B..,Sotiris J..,...&Darst S.A..(2021).Structural origins of Escherichia coli RNA polymerase open promoter complex stability.Proceedings of the National Academy of Sciences of the United States of America,118(40).
MLA	Saecker R.M.,et al."Structural origins of Escherichia coli RNA polymerase open promoter complex stability".Proceedings of the National Academy of Sciences of the United States of America 118.40(2021).