Photosynthesis is the procedure through which plants and other organisms transform light energy into chemical energy.
Photosystem I in plants reveals a hitherto unobserved face/Molecular assessment with high accuracy.
In it, biomass and sugar are produced from the sunlights energy by plants and single-celled algae. Now, for the first time, the structure of a novel protein complex that catalyzes energy conversion procedures in photosynthesis has actually been determined by plant biotechnologists and structural biologists from the Universities of Münster (Germany) and Stockholm (Sweden).
This protein complex is the photosystem I, which is understood as a single protein complex (monomer) in plants. Teacher Michael Hippler of the University of Münster and Professor Alexey Amunts of the University of Stockholm led a group of scientists that demonstrated for the very first time that two photosystem I monomers in plants may come together as a dimer and described the molecular structure of this new sort of molecular maker.
The findings, which have been recently published in the journal Nature Plants, provide molecular insights into the process of photosynthesis with a hitherto unparalleled degree of accuracy. They may assist to utilize the reductive force (the desire to quit electrons) of photosystem I more successfully in the future, for example, to produce hydrogen as a source of energy.
In it, biomass and sugar are produced from the sunlights energy by plants and single-celled algae. Now, for the very first time, the structure of a novel protein complex that catalyzes energy conversion processes in photosynthesis has actually been determined by plant biotechnologists and structural biologists from the Universities of Münster (Germany) and Stockholm (Sweden).
The uptake of light energy into photosystems I and II enable electrons to be transported within the molecular “photosynthetic device”, thus driving the conversion of light energy into chemical energy. In the research study, the researchers define the most precisely available PSI-LHCI design to a resolution of 2.3 Ångström (one Ångström corresponds to one ten-millionth of a millimeter), consisting of the flexibly bound electron transmitter plastocyanin, and they designate the proper identity and orientation to all pigments, as well as to 621 water particles which influence the energy transmission pathways.
The background: There are two photosynthesis complexes, called photosystems I and II, which operate at their best in the case of light with various wavelengths. The uptake of light energy into photosystems I and II make it possible for electrons to be transferred within the molecular “photosynthetic machine”, hence driving the conversion of light energy into chemical energy. At the same time, electrons from photosystem I are sent to the protein ferredoxin.
In green algae, ferredoxin can transfer electrons arising during photosynthesis to an enzyme called hydrogenase, which then produces molecular hydrogen. This molecular hydrogen is therefore produced by the input of light energy, which suggests it is produced renewably and may be able to function as a future source of energy. The researchers asked themselves the concern: “How does the production of photosynthetic hydrogen associate with the structural characteristics of the monomer and dimer photosystem I?
The results in information
The photosystem I homodimer from the green alga Chlamydomonas reinhardtii consists of 40 protein subunits with 118 transmembrane helices supplying a structure for 568 photosynthesis pigments. Using cryogenic electron microscopy, the researchers showed that the lack of subunits with the classification PsaH and Lhca2 leads to a head-to-head orientation of monomer photosystem I (PSI) and its associated light-harvesting proteins (LHCI). The light-harvesting protein Lhca9 is the essential component offering this dimerization.
In the study, the scientists define the most specifically readily available PSI-LHCI design to a resolution of 2.3 Ångström (one Ångström corresponds to one ten-millionth of a millimeter), including the flexibly bound electron transmitter plastocyanin, and they designate the appropriate identity and orientation to all pigments, as well as to 621 water particles which affect the energy transmission pathways. As Michael Hippler says, “The deficiency of Lhca2 promotes the development of PSI dimer, and so we suggest that the hydrogenase might prefer the targeting of photosynthetic electrons from the PSI dimer, as we proposed in our earlier work.
Referral: “Algal photosystem I dimer and high-resolution model of PSI-plastocyanin complex” by Andreas Naschberger, Laura Mosebach, Victor Tobiasson, Sebastian Kuhlgert, Martin Scholz, Annemarie Perez-Boerema, Thi Thu Hoai Ho, André Vidal-Meireles, Yuichiro Takahashi, Michael Hippler, and Alexey Amunts, 13 October 2022, Nature Plants.DOI: 10.1038/ s41477-022-01253-4.