National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R01 GM126891
米国
引用
ジャーナル: Mol Cell / 年: 2021 タイトル: Pre-termination Transcription Complex: Structure and Function. 著者: Zhitai Hao / Vitaly Epshtein / Kelly H Kim / Sergey Proshkin / Vladimir Svetlov / Venu Kamarthapu / Binod Bharati / Alexander Mironov / Thomas Walz / Evgeny Nudler / 要旨: Rho is a general transcription termination factor playing essential roles in RNA polymerase (RNAP) recycling, gene regulation, and genomic stability in most bacteria. Traditional models of ...Rho is a general transcription termination factor playing essential roles in RNA polymerase (RNAP) recycling, gene regulation, and genomic stability in most bacteria. Traditional models of transcription termination postulate that hexameric Rho loads onto RNA prior to contacting RNAP and then translocates along the transcript in pursuit of the moving RNAP to pull RNA from it. Here, we report the cryoelectron microscopy (cryo-EM) structures of two termination process intermediates. Prior to interacting with RNA, Rho forms a specific "pre-termination complex" (PTC) with RNAP and elongation factors NusA and NusG, which stabilize the PTC. RNA exiting RNAP interacts with NusA before entering the central channel of Rho from the distal C-terminal side of the ring. We map the principal interactions in the PTC and demonstrate their critical role in termination. Our results support a mechanism in which the formation of a persistent PTC is a prerequisite for termination.