Study on the regulatory mechanisms of DNA-binding protein complexes through interactions mediated by flexible regions

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K06050
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 43020:Structural biochemistry-related
• Research Institution: Kyushu University
• Principal Investigator: Mayanagi Kouta 九州大学, 薬学研究院, 講師 (50418571)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: クライオ電子顕微鏡 / 立体構造解析 / 超分子複合体 / 生物物理 / 天然変性領域

Outline of Final Research Achievements

Analysis of the nucleosome and the MID domain of the FACT complex visualized the N-terminal tail of histone H3 of the nucleosome binding between the two DNA double strands wrapped around the histone core. In single-particle analysis of the CHD8 remodeling factor and nucleosome complex, a higher resolution (0.39 nm) was obtained compared to the FACT system, but the histone tails were not visualized. This suggests that in this system, the tails extend into the solution away from the nucleosome core. Additionally, cryo-electron microscopy was used to analyze the complex formed by MDP1, which is involved in the dormancy phenomenon of Mycobacterium tuberculosis and has half of its full length occupied by intrinsically disordered regions, along with DNA　and ribosomes.

Free Research Field

構造生物学

Academic Significance and Societal Importance of the Research Achievements

これまで、結晶構造解析等では可視化が困難だった、ヌクレオソームのヒストンテールを明確に可視化され、また結合因子等の様々な要因によりテールがコアに収納されたり、あるいは溶液中に展開されるなど非常にダイナミックに変化し、これが機能制御に利用されている可能性を示せた。
また現在でも非常に重大な疾病である結核菌の、治療を困難にさせる要因の一つの休眠現象に深く関わるMDP1の天然変性領域とDNA、リボソーム等から形成される複合体の解析により、休眠の要因の一つと考えられる凝集体形成の機構の解析が進展した。