Eustigmatophyte model of red-shifted chlorophyll a absorption in light-harvesting complexes.

Autor: Agostini A; Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy. alessandro.agostini.1@unipd.it.; Czech Academy of Sciences, Biology Centre, Institute of Plant Molecular Biology, Branišovská 31, 370 05, České Budějovice, Czech Republic. alessandro.agostini.1@unipd.it., Bína D; Czech Academy of Sciences, Biology Centre, Institute of Plant Molecular Biology, Branišovská 31, 370 05, České Budějovice, Czech Republic.; Institute of Chemistry, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic., Barcytė D; Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic., Bortolus M; Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy., Eliáš M; Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic., Carbonera D; Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy., Litvín R; Czech Academy of Sciences, Biology Centre, Institute of Plant Molecular Biology, Branišovská 31, 370 05, České Budějovice, Czech Republic. rlitvin@prf.jcu.cz.; Institute of Chemistry, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05, České Budějovice, Czech Republic. rlitvin@prf.jcu.cz.
Jazyk: angličtina
Zdroj: Communications biology [Commun Biol] 2024 Oct 29; Vol. 7 (1), pp. 1406. Date of Electronic Publication: 2024 Oct 29.
DOI: 10.1038/s42003-024-07101-9
Abstrakt: Photosynthetic organisms harvest light for energy. Some eukaryotic algae have specialized in harvesting far-red light by tuning chlorophyll a absorption through a mechanism still to be elucidated. Here, we combined optically detected magnetic resonance and pulsed electron paramagnetic resonance measurements on red-adapted light-harvesting complexes, rVCP, isolated from the freshwater eustigmatophyte alga Trachydiscus minutus to identify the location of the pigments responsible for this remarkable adaptation. The pigments have been found to belong to an excitonic cluster of chlorophylls a at the core of the complex, close to the central carotenoids in L1/L2 sites. A pair of structural features of the Chl a403/a603 binding site, namely the histidine-to-asparagine substitution in the magnesium-ligation residue and the small size of the amino acid at the i-4 position, resulting in a [A/G]xxxN motif, are proposed to be the origin of this trait. Phylogenetic analysis of various eukaryotic red antennae identified several potential LHCs that could share this tuning mechanism. This knowledge of the red light acclimation mechanism in algae is a step towards rational design of algal strains in order to enhance light capture and efficiency in large-scale biotechnology applications.
(© 2024. The Author(s).)
Databáze: MEDLINE
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