Structural basis of functional Hfq-binding region of bacterial sRNA

2021 Fiscal Year Final Research Report

• Project/Area Number: 17KK0146
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research)
• Allocation Type: Multi-year Fund
• Research Field: Molecular biology
• Research Institution: Keio University (2020-2021); Suzuka University of Medical Science (2017-2019)
• Principal Investigator: MORITA Teppei 慶應義塾大学, 政策・メディア研究科(藤沢), 特任講師 (10444366)
• Project Period (FY): 2017 – 2021
• Keywords: 小分子RNA / 遺伝子発現 / 転写終結 / Hfq / 細菌 / 低温ショックタンパク質 / Rho

Outline of Final Research Achievements

This project focuses on structural features of the 3’end of bacterial sRNA and the mechanism of sRNA production via transcription termination. We investigated the termination efficiencies of some sRNAs and carried out a multicopy plasmid screen in E. coli to look for genetic factors by which the termination of sRNAs could be modulated. We identified novel factors that attenuate the termination of SgrS sRNA. Biochemical analyses showed effects of each factor on both the termination of sRNAs and the regulation by SgrS of the target mRNAs. These results confirm changes in the efficiency of intrinsic termination as an additional layer of the regulation of sRNA signaling. In addition, RNA-Seq analysis found global effects of CspD, which is one of the isolated factors, on transcription across some regulatory termination sites, such as Riboswithes. This suggests that CspD plays a global regulator in transcription elongation/termination.

Free Research Field

分子生物学

Academic Significance and Societal Importance of the Research Achievements

近年のRNA-Seq技術の発展に伴い、細菌では、これまで考えられていたよりも頻繁に転写の伸長や終結がコントロールされており、細菌生理に関与する事例が報告されているが、転写伸長・終結の制御の分子機構は不明である。本研究において新規に同定した転写終結の抑制機能を持つ遺伝因子は、転写伸長・終結の制御機構の解明の一助となるものである。さらに、これらの因子を応用することで、病原性やバイオフィルムといった細菌生理の新たな制御技術の開発が期待できる。