2020年5月
Structure of a cyanobacterial photosystem I surrounded by octadecameric IsiA antenna proteins
COMMUNICATIONS BIOLOGY
- 巻
- 3
- 号
- 1
- 開始ページ
- 232
- 終了ページ
- 232
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1038/s42003-020-0949-6
- 出版者・発行元
- NATURE PUBLISHING GROUP
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.
- リンク情報
-
- DOI
- https://doi.org/10.1038/s42003-020-0949-6
- PubMed
- https://www.ncbi.nlm.nih.gov/pubmed/32393811
- PubMed Central
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7214436
- Web of Science
- https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000534339100004&DestApp=WOS_CPL
- ID情報
-
- DOI : 10.1038/s42003-020-0949-6
- eISSN : 2399-3642
- PubMed ID : 32393811
- PubMed Central 記事ID : PMC7214436
- Web of Science ID : WOS:000534339100004