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ID 60008
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Akita, Fusamichi Graduate School of Natural Science and Technology, Okayama University ORCID Kaken ID publons researchmap
Nagao, Ryo Research Institute for Interdisciplinary Science, Okayama University Kaken ID publons researchmap
Kato, Koji Research Institute for Interdisciplinary Science, Okayama University ORCID Kaken ID publons researchmap
Nakajima, Yoshiki Graduate School of Natural Science and Technology, Okayama University ORCID
Yokono, Makio Nippon Flour Mills Co., Ltd., Innovation Center
Ueno, Yoshifumi Graduate School of Science, Kobe University
Suzuki, Takehiro Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science
Dohmae, Naoshi Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science
Shen, Jian-Ren Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University ORCID Kaken ID publons researchmap
Akimoto, Seiji Graduate School of Science, Kobe University
Miyazaki, Naoyuki Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba
Abstract
Iron-stress induced protein A (IsiA) is a chlorophyll-binding membrane-spanning protein in photosynthetic prokaryote cyanobacteria, and is associated with photosystem I (PSI) trimer cores, but its structural and functional significance in light harvesting remains unclear. Here we report a 2.7-angstrom resolution cryo-electron microscopic structure of a supercomplex between PSI core trimer and IsiA from a thermophilic cyanobacterium Thermosynechococcus vulcanus. The structure showed that 18 IsiA subunits form a closed ring surrounding a PSI trimer core. Detailed arrangement of pigments within the supercomplex, as well as molecular interactions between PSI and IsiA and among IsiAs, were resolved. Time-resolved fluorescence spectra of the PSI-IsiA supercomplex showed clear excitation-energy transfer from IsiA to PSI, strongly indicating that IsiA functions as an energy donor, but not an energy quencher, in the supercomplex. These structural and spectroscopic findings provide important insights into the excitation-energy-transfer and subunit assembly mechanisms in the PSI-IsiA supercomplex. Akita et al. present the latest approach to solve IsiA-PSI supercomplex molecular structure with increased resolution using cryo-EM and time-resolved fluorescence studies. With 2.7 angstrom resolution, they reveal molecular interactions between PSI and IsiA subunits and that IsiA functions as an energy donor in the supercomplex.
Keywords
Cryoelectron microscopy
Photosystem I
Published Date
2020-05-11
Publication Title
Communications Biology
Volume
volume3
Issue
issue1
Publisher
Nature
Start Page
232
ISSN
2399-3642
Content Type
Journal Article
language
英語
OAI-PMH Set
岡山大学
Copyright Holders
© The Author(s) 2020
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PubMed ID
DOI
Web of Science KeyUT
Related Url
isVersionOf https://doi.org/10.1038/s42003-020-0949-6
License
http://creativecommons.org/licenses/by/4.0/.
Funder Name
Ministry of Education, Culture, Sports, Science and Technology
助成番号
JP17K07442
JP19H04726
JP16H06553
JP17H06434