Structural and biological study of electrode reduction by Geobacteraceae

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05771
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38020:Applied microbiology-related
• Research Institution: University of Miyazaki
• Principal Investigator: Inoue Kengo 宮崎大学, 農学部, 准教授 (70581304)
• Co-Investigator(Kenkyū-buntansha): 和田 啓 宮崎大学, 医学部, 准教授 (80379304)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: Geobacter / 細胞外電子伝達 / シトクロム

Outline of Final Research Achievements

Geobacter sulfurreducens has an extremely high extracellular electron transfer capacity. To elucidate the structure of outer membrane cytochrome OmcZ, which is essential for optimal extracellular electron transfer to the electrode, over expression system of OmcZ in G. sulfurreducens was established and OmcZ was purified. After screening crystallization conditions using the purified OmcZ, crystals were successfully obtained and X-ray diffraction data were collected. The highest resolution data of 2.2 A was successfully obtained. Furthermore, using four types of heavy atoms, Pt, Hg, Au, and Pb, the crystals were soaked into a cryo-solution containing these atoms, and heavy-atom substituted crystals were prepared. Data for phase determination was collected from the obtained crystals.

Free Research Field

応用微生物学

Academic Significance and Societal Importance of the Research Achievements

Geobacter sulfurreducensがもつ細胞外電子伝達能力には電気伝導性ナノワイヤーが重要であることが知られている。これまでにPilA、OmcS、およびOmcZを構成するナノワイヤーが報告されており、これらのうち、OmcZのみその立体構造が明らかになっていない。本研究では、OmcZの立体構造決定を試み、構造解明に十分な分解能の反射データを得ることに成功した。