Bacteriochlorophyll c pigments extracted from light harvesting chlorosomes in green photosynthetic bacteria are known to self-assemble into aggregates whose electronic spectroscopy resembles that of intact chlorosomes. Femtosecond optical experiments reveal that the chlorosomes and their reconstituted aggregates exhibit closely analogous internal energy transfer kinetics and exciton state evolution. These comparisons furnish compelling new evidence that proteins do not exert a major local role in the BChl c antenna pigment organization of intact chlorosomes.
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http://dx.doi.org/10.1016/S0006-3495(95)79983-0 | DOI Listing |
Proc Natl Acad Sci U S A
January 2023
Department of Chemistry, University of Crete, Voutes Heraklion GR-70013, Greece.
Light energy absorption and transfer are very important processes in photosynthesis. In green sulfur bacteria light is absorbed primarily by the chlorosomes and its energy is transferred via the Fenna-Matthews-Olson (FMO) proteins to a homodimeric reaction center (RC). Here, we report the cryogenic electron microscopic structure of the intact FMO-RC apparatus from at 2.
View Article and Find Full Text PDFJ Integr Plant Biol
January 2023
Department of Pathology of Sir Run Run Shaw Hospital, and Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, 310058, China.
The photosynthetic reaction center complex (RCC) of green sulfur bacteria (GSB) consists of the membrane-imbedded RC core and the peripheric energy transmitting proteins called Fenna-Matthews-Olson (FMO). Functionally, FMO transfers the absorbed energy from a huge peripheral light-harvesting antenna named chlorosome to the RC core where charge separation occurs. In vivo, one RC was found to bind two FMOs, however, the intact structure of RCC as well as the energy transfer mechanism within RCC remain to be clarified.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
July 2018
Princess Margaret Cancer Centre, University Health Network, 101 College St., PMCRT 5-354, Toronto, ON, Canada.
Current biomimetics for medical applications use a single biomimetic approach to imitate natural structures, which can be insufficient for reconstructing structurally complex natural systems. Multipronged efforts may resolve these complexities. To achieve interesting nanostructure-driven optical properties, a dual-biomimetic system contained within a single nanoagent was engineered to recapitulate chlorosomes, efficient light-harvesting organelles that have unique dye assemblies and tunable photonic properties.
View Article and Find Full Text PDFJ Biosci Bioeng
October 2017
Department of Chemistry, Faculty of Science and Engineering, Kindai University, Higashi-Osaka, Osaka 577-8502, Japan.
Metabolic substitution of the esterifying chain in bacteriochlorophyll (BChl) c in green photosynthetic bacteria grown by supplementation of exogenous alcohols has attracted attentions to study supramolecular structures and biogenesis of major antenna complexes chlorosomes in these bacteria as well as BChl pigment biosynthesis. Actual substrates in the enzymatic attachment of the esterifying moieties to the precursor of BChl c, namely bacteriochlorophyllide (BChlide) c, in these bacteria are believed to be diphosphate esters of alcoholic substrates, although only intact alcohols have so far been supplemented in the bacterial cultures. We report herein BChl c compositions in the green sulfur photosynthetic bacterium Chlorobaculum tepidum by supplementation with geranyl and geranylgeranyl diphosphates.
View Article and Find Full Text PDFPhotosynthetic antenna systems enable organisms harvesting light and transfer the energy to the photosynthetic reaction centre, where the conversion to chemical energy takes place. One of the most complex antenna systems, the chlorosome, found in the photosynthetic green sulfur bacterium Chlorobaculum (Cba.) tepidum contains a baseplate, which is a scaffolding super-structure, formed by the protein CsmA and bacteriochlorophyll a.
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