Structural basis of the chemotaxis regulatory system using oxygen gas as a signaling molecule

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20750
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0802:Biomedical structure and function and related fields
• Research Institution: Institute for Molecular Science (2022); Center for Novel Science Initatives, National Institutes of Natural Sciences (2021)
• Principal Investigator: Tohda Rei 分子科学研究所, 生命・錯体分子科学研究領域, IMSフェロー (10908122)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 構造生物学 / センサータンパク質 / 生命金属

Outline of Final Research Achievements

HemAT is a heme-containing signal transducer protein that recognizes oxygen molecules as signal molecules. HemAT regulates bacterial chemotaxis by forming a complex with CheA and CheW. However, the mechanisms of how oxygen is sensed and signaled during this process are not clear yet.
In this study, signal-on (oxygen-bound form) and signal-off (oxygen-unbound form) structures of the HemAT sensor domain were determined. By comparing these structures, I found that some amino acid residues around the heme are responsible for signal transduction.

Free Research Field

構造生物学

Academic Significance and Societal Importance of the Research Achievements

バクテリアは、周辺に存在する誘引物質や忌避物質の濃度勾配に応じてその運動性を制御している。本研究課題により、代表的な生体内シグナル伝達システムの1つである走化性制御系の詳細な構造機能相関が明らかになることによって、生物が持つ外部環境に対する応答機能の理解に貢献することができる。