Research findings from a study conducted by the Okayama University in Japan and the Chinese Academy of Sciences are likely to work as blueprints for development of artificial photosynthetic systems.
Results from the study, published in AAAS Science magazine, resolves structure of photosystem I (PSI) to a spatial resolution of 0.28nm.
This reveals the mechanisms related to the conversion of carbon dioxide into sugars that allows for high-efficiency energy transfer in photosynthetic organisms.
Two photosystems are present in thylakoid membranes of oxygenic photosynthetic organisms, of which PSI generates light energy that supports a chain of electron transfer reactions.
These reactions lead to the production of reduction power that enables CO2’s conversion into sugars.
Okayama University said: "In higher plants, the core of PSI is surrounded by a large light-harvesting complex I (LHCI), which forms a PSI-LHCI supercomplex with a total molecular mass of 600kDa.
"The light energy captured by LHCI is transferred to the PSI core with an extremely high efficiency."
PSI-LHCI supercomplex has been reported to have a crystal structure, which till date lacked sufficient resolution to indicate "the detailed organization of the PSI-LHCI supercomplex with atomic precision, especially with respect to the positions and number of cofactors associated with LHCI."
Conducted by Michi Suga, Jian-Ren Shen from Okayama University and Tingyun Kuang and Xiaochun Qin from Chinese Academy of Sciences, the study has resolved the crystal structure of plant PSI-LHCI supercomplex to a resolution of 2.8 Ã….
The findings have been able to point out detailed organisation of protein subunits and cofactors, which allowed evaluating mechanisms of energy transfer, regulation, and photoprotection within the PSI-LHCI supercomplex on a more robust structural basis.
The structural insights of the energy absorption and transfer mechanisms in photosynthesis are expected to help in further research and development works.
It is also likely to serve as a "blueprint for the design of light-harvesting setups with extremely high efficiencies that can be utilized in artificial photosynthetic systems," Okayama University said.
Image:Crystal structure of plant PSI-LHCI supercomplex. Photo: courtesy of Okayama University.
