Identification of novel electron transfer enzymes functionally complementing cytochrome bc1 complex working in photosynthetic electron transfer pathways

• Project/Area Number: 18K06295
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 44030:Plant molecular biology and physiology-related
• Research Institution: Kanagawa University
• Principal Investigator: Nagashima Kenji 神奈川大学, 付置研究所, 研究員 (80264589)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2020: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000); Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2018: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: 光合成電子伝達 / シトクロム / 紅色細菌 / 遺伝子操作 / 紅色光合成細菌 / クライオ電子顕微鏡 / 光合成 / 電子伝達 / シトクロムbc複合体 / チトクロムbc複合体

Outline of Final Research Achievements

Cytochrome bc1 complex has been considered as an essential component in photosynthetic electron transport processes. However, it was first shown in this study that a mutant of purple bacteria lacking the genes coding this complex is capable of photosynthetic growth ability. This suggests a presence of novel enzymes complementing the function of the cytochrome bc1 which oxidizes quinols and reduces soluble electron carriers. Although such novel enzymes could not be isolated, a soluble protein reduced by these novel enzymes and working as an electron donor to the photochemical reaction center was identified as a mono-heme cytochrome c which natural function is reduction of nitrous oxygen. And, a process of transferring the quinol molecules derived from the photochemical reaction centers to the cytochrome bc1 complex was successfully visualized.

Academic Significance and Societal Importance of the Research Achievements

光合成電子伝達という、よく研究されその構成要素も固定されてきた反応系が、別の構成要素を利用し別の電子伝達反応系と動的にリンクしうることが分かったことが最大の成果である。加えてその過程の一部を可視化できたことも学術的に大きな成果であると言える。これらの成果を活用し、シトクロム等の構成要素の欠落や導入、あるいは部位特異的変異の導入により、光合成の電子の流れを人為的に変え、有用物質の大量合成や環境浄化に利用できるようになると期待できる。

Research Products

• [Journal Article] Asymmetric structure of the native Rhodobacter sphaeroides dimeric LH1?RC complex (2022)
  • Author(s): Tani Kazutoshi、Kanno Ryo、Kikuchi Riku、Kawamura Saki、Nagashima Kenji V. P.、Hall Malgorzata、Takahashi Ai、Yu Long-Jiang、Kimura Yukihiro、Madigan Michael T.、Mizoguchi Akira、Humbel Bruno M.、Wang-Otomo Zheng-Yu
  • Journal Title: Nature Communications Volume: 13 Issue: 1 Pages: 1904-1904
  • DOI: 10.1038/s41467-022-29453-8
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A Ca2+-binding motif underlies the unusual properties of certain photosynthetic bacterial core light-harvesting complexes (2022)
  • Author(s): Tani Kazutoshi、Kobayashi Kazumi、Hosogi Naoki、Ji Xuan-Cheng、Nagashima Sakiko、Nagashima Kenji V.P.、Izumida Airi、Inoue Kazuhito、Tsukatani Yusuke、Kanno Ryo、Hall Malgorzata、Yu Long-Jiang、Ishikawa Isamu、Okura Yoshihiro、Madigan Michael T.、Mizoguchi Akira、Humbel Bruno M.、Kimura Yukihiro、Wang-Otomo Zheng-Yu
  • Journal Title: Journal of Biological Chemistry Volume: - Issue: 6 Pages: 101967-101967
  • DOI: 10.1016/j.jbc.2022.101967
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] An LH1-RC photocomplex from an extremophilic phototroph provides insight into origins of two photosynthesis proteins (2022)
  • Author(s): Tani Kazutoshi、Kanno Ryo、Kurosawa Keigo、Takaichi Shinichi、Nagashima Kenji V. P.、Hall Malgorzata、Yu Long-Jiang、Kimura Yukihiro、Madigan Michael T.、Mizoguchi Akira、Humbel Bruno M.、Wang-Otomo Zheng-Yu
  • Journal Title: Communications Biology Volume: 5 Issue: 1 Pages: 1197-1197
  • DOI: 10.1038/s42003-022-04174-2
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Photosynthetic Growth and Energy Conversion in an Engineered Phototroph Containing Thermochromatium tepidum Light-Harvesting Complex 1 and the Rhodobacter sphaeroides Reaction Center Complex (2021)
  • Author(s): Nagashima Kenji V. P.、Nagashima Sakiko、Kitashima Masaharu、Inoue Kazuhito、Madigan Michael T.、Kimura Yukihiro、Wang-Otomo Zheng-Yu
  • Journal Title: Biochemistry Volume: 60 Issue: 36 Pages: 2685-2690
  • DOI: 10.1021/acs.biochem.1c00462
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A previously unrecognized membrane protein in the Rhodobacter sphaeroides LH1-RC photocomplex (2021)
  • Author(s): Tani Kazutoshi、Nagashima Kenji V. P.、Kanno Ryo、Kawamura Saki、Kikuchi Riku、Hall Malgorzata、Yu Long-Jiang、Kimura Yukihiro、Madigan Michael T.、Mizoguchi Akira、Humbel Bruno M.、Wang-Otomo Zheng-Yu
  • Journal Title: Nature Communications Volume: 12 Issue: 1 Pages: 6300-6300
  • DOI: 10.1038/s41467-021-26561-9
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Sequential energy transfer driven by monoexponential dynamics in a biohybrid light-harvesting complex 2 (LH2) (2020)
  • Author(s): Yoneda Y, Kato D, Kondo M, Nagashima KVP, Miyasaka H, Nagasawa Y, Dewa T
  • Journal Title: Photosynthesis Research Volume: 143 Issue: 2 Pages: 115-128
  • DOI: 10.1007/s11120-019-00677-y
  • Peer Reviewed
• [Journal Article] Biochemical and Spectroscopic Characterizations of a Hybrid Light-Harvesting Reaction Center Core Complex (2018)
  • Author(s): Kimura Yukihiro、Hashimoto Kanako、Akimoto Seiji、Takenouchi Mizuki、Suzuki Kengo、Kishi Rikako、Imanishi Michie、Takenaka Shinji、Madigan Michael T.、Nagashima Kenji V. P.、Wang-Otomo Zheng-Yu
  • Journal Title: Biochemistry Volume: 57 Issue: 30 Pages: 4496-4503
  • DOI: 10.1021/acs.biochem.8b00644
  • Peer Reviewed / Int'l Joint Research
• [Presentation] 紅色細菌Rubrivivax gelatinosusの光合成における代替え的な電子伝達循環経路の発見 (2019)
  • Author(s): 永島賢治、永島咲子、佐藤剛、井上和仁
  • Organizer: 第60回日本植物生理学会年会
• [Presentation] Cytochromes c working in the alternative cyclic electron transfer pathway of photosynthesis found in the beta-purple bacterium, Rubrivivax gelatinosus (2018)
  • Author(s): Kenji V. P. Nagashima, Sakiko Nagashima, André Verméglio, Kazuhito Inoue
  • Organizer: International Symposium on Phototrophic Prokaryotes
  • Int'l Joint Research
• [Book] 光合成細菌 (2020)
  • Author(s): 嶋田 敬三、高市 真一
  • Total Pages: 320
  • Publisher: 裳華房
  • ISBN: 9784785358709