The Sm-like RNA chaperone Hfq mediates transcription antitermination at Rho-dependent terminators
The Sm-like RNA chaperone Hfq mediates transcription antitermination at Rho-dependent terminators
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DOI：
10.1038/emboj.2011.192
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发表时间：
2011-07-20
期刊：
影响因子：
11.4
通讯作者：
Boudvillain, Marc
中科院分区：
文献类型：
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作者：
Rabhi, Makhlouf;Espeli, Olivier;Boudvillain, Marc
在大肠杆菌中，必需的运动蛋白Rho以一种尚未完全了解的严格控制的方式促进转录终止。在这里，我们发现一般的转录后调节蛋白Hfq与Rho相关，调节Rho的功能。Hfq：Rho复合体可以通过RNA将这两个因子连接起来，以抑制Rho的ATP水解和双链解离活性，并在体外和体内介导Rho依赖终止子的转录抗终止。在典型终止子(Lambda TR1)上的反终止需要Hfq与终止子上游直接富含A/U的转录区结合。抗终止受反式作用因子(NusG或核酸竞争对手)的调节，这些因子影响HfQ与Rho或RNA的联系。这些数据揭示了一个新的HfQ功能和一个新的转录调控机制，对细菌RNA代谢、基因沉默和致病性具有潜在的重要意义。EMBO期刊(2011)30,2805-2816。DOI：10.1038/Intemj.2011.192；2011年6月14日在线发布
In Escherichia coli, the essential motor protein Rho promotes transcription termination in a tightly controlled manner that is not fully understood. Here, we show that the general post-transcriptional regulatory protein Hfq associates with Rho to regulate Rho function. The Hfq: Rho complex can be further stabilized by RNA bridging both factors in a configuration that inhibits the ATP hydrolysis and duplex unwinding activities of Rho and that mediates transcription antitermination at Rho-dependent terminators in vitro and in vivo. Antitermination at a prototypical terminator (lambda tR1) requires Hfq binding to an A/U-rich transcript region directly upstream from the terminator. Antitermination is modulated by trans-acting factors (NusG or nucleic acid competitors) that affect Hfq association with Rho or RNA. These data unveil a new Hfq function and a novel transcription regulatory mechanism with potentially important implications for bacterial RNA metabolism, gene silencing, and pathogenicity. The EMBO Journal ( 2011) 30, 2805-2816. doi:10.1038/emboj.2011.192; Published online 14 June 2011