PSI of the Colonial Alga Botryococcus braunii Has an Unusually Large Antenna Size
| Autor: | Egbert J. Boekema, Tomas E. van den Berg, Roberta Croce, Wojciech J. Nawrocki, Roman Kouřil, Rameez Arshad |
|---|---|
| Přispěvatelé: | Electron Microscopy, Biophysics Photosynthesis/Energy, LaserLaB - Energy |
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
PROTEINS Physiology Energy transfer ORGANIZATION Plant Science Photosynthesis 01 natural sciences 7. Clean energy CHLAMYDOMONAS-REINHARDTII Fluorescence spectroscopy law.invention law Genetics Botryococcus braunii LIGHT-HARVESTING COMPLEX LHCI STATE TRANSITIONS biology Chemistry biology.organism_classification DEFICIENCY SEPARATION Biophysics PHOTOSYSTEM-I SUPERCOMPLEX Electron microscope Antenna (radio) ENERGY-TRANSFER 010606 plant biology & botany Sugar production |
| Zdroj: | Plant Physiology, 184(4), 2040-2051. AMER SOC PLANT BIOLOGISTS van den Berg, T E, Arshad, R, Nawrocki, W J, Boekema, E J, Kouril, R & Croce, R 2020, ' PSI of the colonial alga Botryococcus braunii has an unusually large antenna size ', Plant physiology, vol. 184, no. 4, pp. 2040-2051 . https://doi.org/10.1104/pp.20.00823 Plant physiology, 184(4), 2040-2051. American Society of Plant Biologists |
| ISSN: | 1532-2548 0032-0889 |
| Popis: | The green alga B.braunii lives in colonies where cells are shading each other and it has developed a large capacity for harvesting light while maintaining a high light-to-energy conversion efficiency. PSI is an essential component of the photosynthetic apparatus of oxygenic photosynthesis. While most of its subunits are conserved, recent data have shown that the arrangement of the light-harvesting complexes I (LHCIs) differs substantially in different organisms. Here we studied the PSI-LHCI supercomplex of Botryococccus braunii, a colonial green alga with potential for lipid and sugar production, using functional analysis and single-particle electron microscopy of the isolated PSI-LHCI supercomplexes complemented by time-resolved fluorescence spectroscopy in vivo. We established that the largest purified PSI-LHCI supercomplex contains 10 LHCIs (similar to 240 chlorophylls). However, electron microscopy showed heterogeneity in the particles and a total of 13 unique binding sites for the LHCIs around the PSI core. Time-resolved fluorescence spectroscopy indicated that the PSI antenna size in vivo is even larger than that of the purified complex. Based on the comparison of the known PSI structures, we propose that PSI in B. braunii can bind LHCIs at all known positions surrounding the core. This organization maximizes the antenna size while maintaining fast excitation energy transfer, and thus high trapping efficiency, within the complex. |
| Databáze: | OpenAIRE |
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