https://scholars.lib.ntu.edu.tw/handle/123456789/592946
標題: | Structure of a photosystem I-ferredoxin complex from a marine cyanobacterium provides insights into far-red light photoacclimation | 作者: | Gisriel, Christopher J. Flesher, David A. Shen, Gaozhong Wang, Jimin MING-YANG HO Brudvig, Gary W. Bryant, Donald A. |
公開日期: | 1-一月-2022 | 出版社: | American Society for Biochemistry and Molecular Biology Inc. | 卷: | 298 | 期: | 1 | 起(迄)頁: | 101408 | 來源出版物: | Journal of Biological Chemistry | 摘要: | Far-red light photoacclimation exhibited by some cyanobacteria allows these organisms to use the far-red region of the solar spectrum (700–800 nm) for photosynthesis. Part of this process includes the replacement of six photosystem I (PSI) subunits with isoforms that confer the binding of chlorophyll (Chl) f molecules that absorb far-red light (FRL). However, the exact sites at which Chl f molecules are bound are still challenging to determine. To aid in the identification of Chl f-binding sites, we solved the cryo-EM structure of PSI from far-red light-acclimated cells of the cyanobacterium Synechococcus sp. PCC 7335. We identified six sites that bind Chl f with high specificity and three additional sites that are likely to bind Chl f at lower specificity. All of these binding sites are in the core-antenna regions of PSI, and Chl f was not observed among the electron transfer cofactors. This structural analysis also reveals both conserved and non-conserved Chl f-binding sites, the latter of which exemplify the diversity in FRL-PSI among species. We found that the FRL–PSI structure also contains a bound soluble ferredoxin, PetF1, at low occupancy, which suggests that ferredoxin binds less transiently than expected according to the canonical view of ferredoxin-binding to facilitate electron transfer. We suggest that this may result from structural changes in FRL-PSI that occur specifically during FRL photoacclimation. |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/592946 | ISSN: | 0021-9258 | DOI: | 10.1016/j.jbc.2021.101408 | SDG/關鍵字: | Antennas; Electron transitions; Medical imaging; Molecules; Binding-sites; Cyanobacteria Synechococcus; Cyanobacterium; Electron transfer; Far-red lights; High specificity; Isoforms; Marine cyanobacteria; Photosystems; Solar spectrum; Binding sites |
顯示於: | 生命科學系 |
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