The structural and functional analysis of the cyacnobacterial circadian clock protein KaiB

• Project/Area Number: 15K18492
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Structural biochemistry
• Research Institution: Nagoya City University
• Principal Investigator: TANIYAMA Reiko 名古屋市立大学, 大学院薬学研究科, その他 (00444365)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2016: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2015: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: 生物時計 / 藍色細菌 / 概日リズム / 溶液散乱 / 超分子質量分析 / 中性子小角散乱 / X線結晶構造解析

Outline of Final Research Achievements

The circadian clock is an endogenous biological mechanism that generates autonomous daily cycles. The molecular machinery of the cyanobacterial circadian clock consists of three proteins, KaiA, KaiB, and KaiC. The time information is transmitted from KaiC to SasA.
We showed that mass-spectrometric titration data of KaiB-KaiC complex showed that the proteins formed a complex exclusively in a 6:6 stoichiometry and that the inverse contrast-matching technique of small-angle neutron scattering revealed a disk-shaped arrangement of the KaiB subunits on the outer surface of the KaiC ring, suggesting that cooperatively binding KaiB competes with SasA with respect to interaction with KaiC. On the other hand, KaiB enhanced KaiA-KaiC complex formation. These results suggested that the KaiB play the important role in the regulation of Kai protein complex formation.

Research Products

• [Journal Article] Structural characterization of the circadian clock protein complex composed of KaiB and KaiC by inverse contrast matching small-angle neutron scattering (2016)
  • Author(s): M. Sugiyama, H. Yagi, K. Ishii, L. Porcar, A. Martel, K. Oyama, M. Noda, Y. Yunoki, R. Murakami, R. Inoue, N. Sato, Y. Oba, K. Terauchi, S. Uchiyama, K. Kato
  • Journal Title: Sci. Rep. Volume: 6 Issue: 1 Pages: 35567-35567
  • DOI: 10.1038/srep35567
  • NAID: 120006223630
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Circadian oscillations of KaiA-KaiC and KaiB-KaiC complex formations in an in vitro reconstituted KaiABC clock oscillator. (2016)
  • Author(s): Murakami R, Mutoh R, Ishii K, Ishiura M.
  • Journal Title: Genes Cells. Volume: 21 Issue: 8 Pages: 890-900
  • DOI: 10.1111/gtc.12392
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Presentation] Structural characterization of circadian clock protein complexes by small-angle neutron scattering and native mass spectrometry analyses (2017)
  • Author(s): Yunoki, Y., Sugiyama, M., Yagi, H., Ishii, K., Oyama, K., Porcar, L., Martel, A., Noda, M., Murakami, R., Inoue, R., Sato, N., Oba, Y., Terauchi, K., Uchiyama, S. & Kato, K.
  • Organizer: 新学術領域「動的秩序と機能」第5回国際シンポジウム
  • Place of Presentation: 東京大学
  • Year and Date: 2017-01-21
  • Int'l Joint Research
• [Presentation] 物理化学的計測による時計タンパク質複合体の構造解析 (2017)
  • Author(s): 柚木康弘, 杉山正明, 矢木宏和, 石井健太郎, 大山克明, Lionel Porcar, Anne Martel, 野田勝紀, 村上怜子, 井上倫太郎, 佐藤伸浩, 大場洋次郎, 寺内一姫, 内山 進, 加藤晃一
  • Organizer: 第81回生化学会中部支部会
  • Place of Presentation: 名古屋市立大学
• [Presentation] Conformational and Stoichiometric Characterization of Protein Complexes by Small-angle Neutron Scattering in Conjunction with Native Mass Spectrometry (2016)
  • Author(s): YUNOKI, Yasuhiro・ISHII, Kentaro・MURAKAMI, Reiko・NODA, Masanori・YAGI, Hirokazu・INOUE, Rintaro・SUGIYAMA, Masaaki・UCHIYAMA, Susumu・KATO, Koichi
  • Organizer: 日本化学会第96春季年会
  • Place of Presentation: 京都、同志社大学、京田辺キャンパス
  • Year and Date: 2016-03-24
• [Presentation] 藍色細菌の時計関連タンパク質SasAが生物時計によって発振される時間情報を出力する分子機構の解明 (2016)
  • Author(s): 村上 怜子、矢木 宏和、石井 健太郎、柚木 康弘、内山 進、石浦 正寛、加藤 晃一
  • Organizer: 超異分野学会
  • Place of Presentation: 京都、オムロン京都センターヒル啓真館
  • Year and Date: 2016-03-19