小柯机器人

细胞内原位解析细菌表达组结构
2020-08-01 16:25

德国柏林工业大学Juri Rappsilber、欧洲分子生物学实验室Julia Mahamid等研究人员,合作解析了活跃转录-翻译表达组的细胞内结构。相关论文发表在2020年7月31日出版的《科学》杂志上。

研究人员使用人类病原体肺炎支原体开发了一种整合的细胞内结构方法。研究人员结合了全细胞交联质谱、细胞冷冻电子断层扫描以及集成建模来确定亚纳米分辨率下转录和翻译表达组的细胞内结构。
 
该表达组包含RNA聚合酶(RNAP)、核糖体和转录延伸因子NusG和NusA。研究人员在与NusG结合的延长RNAP和核糖体之间的界面上精确定位了NusA,并认为它可以介导转录-翻译偶联。翻译抑制使表达组解离,而转录抑制使它停滞并重新排列。因此,活跃表达组构架需要细胞内的翻译和转录延伸。
 
据悉,在细胞内部进行结构生物学研究可以捕获天然环境中起作用的分子机器。
 
附:英文原文
 
Title: In-cell architecture of an actively transcribing-translating expressome

Author: Francis J. O’Reilly, Liang Xue, Andrea Graziadei, Ludwig Sinn, Swantje Lenz, Dimitry Tegunov, Cedric Bltz, Neil Singh, Wim J. H. Hagen, Patrick Cramer, Jrg Stülke, Julia Mahamid, Juri Rappsilber

Issue&Volume: 2020/07/31

Abstract: Structural biology studies performed inside cells can capture molecular machines in action within their native context. In this work, we developed an integrative in-cell structural approach using the genome-reduced human pathogen Mycoplasma pneumoniae. We combined whole-cell cross-linking mass spectrometry, cellular cryo–electron tomography, and integrative modeling to determine an in-cell architecture of a transcribing and translating expressome at subnanometer resolution. The expressome comprises RNA polymerase (RNAP), the ribosome, and the transcription elongation factors NusG and NusA. We pinpointed NusA at the interface between a NusG-bound elongating RNAP and the ribosome and propose that it can mediate transcription-translation coupling. Translation inhibition dissociated the expressome, whereas transcription inhibition stalled and rearranged it. Thus, the active expressome architecture requires both translation and transcription elongation within the cell.

DOI: 10.1126/science.abb3758

Source: https://science.sciencemag.org/content/369/6503/554

Science:《科学》,创刊于1880年。隶属于美国科学促进会,最新IF:41.037
官方网址:https://www.sciencemag.org/
投稿链接:https://cts.sciencemag.org/scc/#/login

本期文章:《科学》:Volume 369 Issue 6503

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