6VPV

Trimeric Photosystem I from the High-Light Tolerant Cyanobacteria Cyanobacterium Aponinum

Summary for 6VPV

• Entry DOI: 10.2210/pdb6vpv/pdb
• Related: 1JB0 5OY0
• EMDB information: 21320
• Descriptor: Photosystem I P700 chlorophyll a apoprotein A1, Photosystem I reaction center subunit XI, Photosystem I reaction center subunit XII, ... (19 entities in total)
• Functional Keywords: photosystem i, membrane protein, photosynthesis, psi
• Biological source: Cyanobacterium aponinum 0216; More
• Total number of polymer chains: 33
• Total formula weight: 1051662.36

Authors

Dobson, Z.,Toporik, H.,Vaughn, N.,Lin, S.,Williams, D.,Fromme, P.,Mazor, Y. (deposition date: 2020-02-04, release date: 2021-08-04, Last modification date: 2024-11-20)

Primary citation

Dobson, Z.,Ahad, S.,Vanlandingham, J.,Toporik, H.,Vaughn, N.,Vaughn, M.,Williams, D.,Reppert, M.,Fromme, P.,Mazor, Y.
The structure of photosystem I from a high-light tolerant Cyanobacteria.
Elife, 10:-, 2021

PubMed Abstract: Photosynthetic organisms have adapted to survive a myriad of extreme environments from the earth's deserts to its poles, yet the proteins that carry out the light reactions of photosynthesis are highly conserved from the cyanobacteria to modern day crops. To investigate adaptations of the photosynthetic machinery in cyanobacteria to excessive light stress, we isolated a new strain of cyanobacteria, 0216, from the extreme light environment of the Sonoran Desert. Here we report the biochemical characterization and the 2.7 Å resolution structure of trimeric photosystem I from this high-light-tolerant cyanobacterium. The structure shows a new conformation of the PsaL C-terminus that supports trimer formation of cyanobacterial photosystem I. The spectroscopic analysis of this photosystem I revealed a decrease in far-red absorption, which is attributed to a decrease in the number of long- wavelength chlorophylls. Using these findings, we constructed two chimeric PSIs in sp. PCC 6803 demonstrating how unique structural features in photosynthetic complexes can change spectroscopic properties, allowing organisms to thrive under different environmental stresses.

PubMed: 34435952
DOI: 10.7554/eLife.67518

Experimental method

ELECTRON MICROSCOPY (2.7 Å)