2019 Fiscal Year Final Research Report
Reassessment of survival strategy during post-exponential growth phase by exploring novel functions of the transcription machinery and related networks.
| Project/Area Number |
16H04903
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied microbiology
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| Research Institution | Tokyo University of Agriculture |
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Principal Investigator |
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | RNA ポリメラーゼ / コア酵素 / 転写開始機構 / プロモーター認識 / 緊縮応答 / 異種遺伝子発現 / 枯草菌 / 耐熱化 |
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| Outline of Final Research Achievements |
Fundamental biological functions are typically consolidated during the stage after logarithmic growth phase and various phenomena related in this stage have been found to be associated with transcriptional machinery in Bacillus subtilis. Our findings are summarized in three aspects. One, the deceleration of transcription grant thermotolerance to the cells. Two, the altered preference of the initiation nucleotide confers stringent response independent on the cellular GTP level. Third, the altered preference of discriminator sequence makes the cells possible to recognize heterogeneous promoter. These findings uncovered new functions of RNA polymerase core enzyme, which had an important role for the survival strategy during the post-exponential growth phase. In addition, our comprehensive study on the stringent control revealed that an S-adenosyl methionine (SAM) had a role on the de novo GTP biosynthesis pathway by regulating the activity of the IMP dehydrogenase, GuaB.
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| Free Research Field |
微生物遺伝学
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| Academic Significance and Societal Importance of the Research Achievements |
転写装置に関する知見は多いが、本研究のように対数増殖後期の細胞機能が転写装置と密接な接点を持つことが新たに判明し、特にコア酵素の役割は単なる重合酵素ではなく、さまざまな制御機構に関わっていることを明らかにした。プロモーターや転写開始点認識に関わるコア酵素の役割は、50年近く謎であった現象を解明した点で学術的意義は高い。またメチオニン感受性は不可思議な現象であったが、GTP合成系との関連を解明した点は核酸代謝における大きな学術的成果である。本研究の成果は、転写装置の新しい知見を元に異種遺伝子発現における種の壁を越えるアイデアに発展し、微生物生産という産業レベルでも大きな社会的意義も包括している。
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