| Project/Area Number |
19K06581
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 43040:Biophysics-related
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| Research Institution | Kanazawa University |
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Principal Investigator |
NGO XUANKIEN 金沢大学, ナノ生命科学研究所, 特任助教 (60778190)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2021: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2020: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2019: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
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| Keywords | ABC transporter / Lipid A / High-speed AFM / MsbA / ABC transporters / lipid A / lipopolysaccharide / proteoliposomes / giant proteovesicles / HS-AFM / STED confocal microsopy / BtuCDF / Vitamin B12 / Proteoliposomes / Nanodiscs / ABC Transporter MsbA / High Speed AFM / Membrane Protein / Nanodisc |
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| Outline of Research at the Start |
MsbA, an ATP-binding cassette (ABC) transporter, transports and flips lipid A and lipopolysaccharides across the cytoplasmic membrane of Gram-negative bacteria. Biochemical assays and HS-AFM are using to real-time image and analyze the structural dynamics of MsbA during transportation of lipids.
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| Outline of Final Research Achievements |
Our recent precise analyses on structural dynamics of bacterial ABC transporter MsbA using High-speed Atomic Force Microscopy (HS-AFM) show that lipid A/lipopolysaccharide (LPS) after flipping across inner membrane (IM) remains in the transmembrane domains (TMDs) core of MsbA even during many ATPase cycles. Bound ATP locks two NBDs in closed conformation for maintaining an outward-facing conformation that facilitates the flipping of lipid A/LPS across IM. ATPase activity of MsbA (ATP→ADP.Pi) may always go on during and after flipping of lipid A/LPS across membrane. When lipid A/LPS is trapped inside TMDs core of MsbA bound ATP, we do not observe the conformational transitions between inward-facing and outward-facing as reported in the previous hypotheses. Currently, we continue this study to unravel the correlation between the structural dynamics and transport activity of MsbA.
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| Academic Significance and Societal Importance of the Research Achievements |
Our study is important to precisely understand the working mechanism of lipid A transport from the IM to OM by MsbA in bacteria.
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