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Llansola-Portoles MJ, Pascal AA, Robert B. Resonance Raman: A powerful tool to interrogate carotenoids in biological matrices. Methods Enzymol 2022; 674:113-135. [DOI: 10.1016/bs.mie.2022.03.068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Arulmozhiraja S, Nakatani N, Nakayama A, Hasegawa JY. Energy dissipative photoprotective mechanism of carotenoid spheroidene from the photoreaction center of purple bacteria Rhodobacter sphaeroides. Phys Chem Chem Phys 2015; 17:23468-80. [PMID: 26292635 DOI: 10.1039/c5cp03089g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carotenoid spheroidene (SPO) functions for photoprotection in the photosynthetic reaction centers (RCs) and effectively dissipates its triplet excitation energy. Sensitized cis-to-trans isomerization was proposed as a possible mechanism for a singlet-triplet energy crossing for the 15,15'-cis-SPO; however, it has been questioned recently. To understand the dissipative photoprotective mechanism of this important SPO and to overcome the existing controversies on this issue, we carried out a theoretical investigation using density functional theory on the possible triplet energy relaxation mechanism through the cis-to-trans isomerization. Together with the earlier experimental observations, the possible mechanism was discussed for the triplet energy relaxation of the 15,15'-cis-SPO. The result shows that complete cis-to-trans isomerization is not necessary. Twisting the C15-C15' bond leads to singlet-triplet energy crossing at ϕ(14,15,15',14') = 77° with an energy 32.5 kJ mol(-1) (7.7 kcal mol(-1)) higher than that of the T1 15,15'-cis minimum. Further exploration of the minimum-energy intersystem crossing (MEISC) point shows that triplet relaxation could occur at a less distorted structure (ϕ = 58.4°) with the energy height of 26.5 KJ mol(-1) (6.3 kcal mol(-1)). Another important reaction coordinate to reach the MEISC point is the bond-length alternation. The model truncation effect, solvent effect, and spin-orbit coupling were also investigated. The singlet-triplet crossing was also investigated for the 13,14-cis stereoisomer and locked-13,14-cis-SPO. We also discussed the origin of the natural selection of the cis over trans isomer in the RC.
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Affiliation(s)
- Sundaram Arulmozhiraja
- Catalysis Research Center, Hokkaido University, Kita 21, Nishi 10, Kita-ku, Sapporo 001-0021, Japan.
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Saw JHW, Schatz M, Brown MV, Kunkel DD, Foster JS, Shick H, Christensen S, Hou S, Wan X, Donachie SP. Cultivation and complete genome sequencing of Gloeobacter kilaueensis sp. nov., from a lava cave in Kīlauea Caldera, Hawai'i. PLoS One 2013; 8:e76376. [PMID: 24194836 PMCID: PMC3806779 DOI: 10.1371/journal.pone.0076376] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 08/24/2013] [Indexed: 02/05/2023] Open
Abstract
The ancestor of Gloeobacter violaceus PCC 7421T is believed to have diverged from that of all known cyanobacteria before the evolution of thylakoid membranes and plant plastids. The long and largely independent evolutionary history of G. violaceus presents an organism retaining ancestral features of early oxygenic photoautotrophs, and in whom cyanobacteria evolution can be investigated. No other Gloeobacter species has been described since the genus was established in 1974 (Rippka et al., Arch Microbiol 100:435). Gloeobacter affiliated ribosomal gene sequences have been reported in environmental DNA libraries, but only the type strain's genome has been sequenced. However, we report here the cultivation of a new Gloeobacter species, G. kilaueensis JS1T, from an epilithic biofilm in a lava cave in Kīlauea Caldera, Hawai'i. The strain's genome was sequenced from an enriched culture resembling a low-complexity metagenomic sample, using 9 kb paired-end 454 pyrosequences and 400 bp paired-end Illumina reads. The JS1T and G. violaceus PCC 7421T genomes have little gene synteny despite sharing 2842 orthologous genes; comparing the genomes shows they do not belong to the same species. Our results support establishing a new species to accommodate JS1T, for which we propose the name Gloeobacter kilaueensis sp. nov. Strain JS1T has been deposited in the American Type Culture Collection (BAA-2537), the Scottish Marine Institute's Culture Collection of Algae and Protozoa (CCAP 1431/1), and the Belgian Coordinated Collections of Microorganisms (ULC0316). The G. kilaueensis holotype has been deposited in the Algal Collection of the US National Herbarium (US# 217948). The JS1T genome sequence has been deposited in GenBank under accession number CP003587. The G+C content of the genome is 60.54 mol%. The complete genome sequence of G. kilaueensis JS1T may further understanding of cyanobacteria evolution, and the shift from anoxygenic to oxygenic photosynthesis.
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Affiliation(s)
- Jimmy H. W. Saw
- Department of Microbiology, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States of America
| | - Michael Schatz
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America
| | - Mark V. Brown
- NASA Astrobiology Institute, University of Hawai'i, Honolulu, Hawai'i, United States of America
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | - Dennis D. Kunkel
- Dennis Kunkel Microscopy, Inc., Kailua, Hawai'i, United States of America
| | - Jamie S. Foster
- Department of Microbiology and Cell Science, University of Florida Space Life Science Laboratory, Kennedy Space Center, Kennedy, Florida, United States of America
| | | | - Stephanie Christensen
- Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, Honolulu, Hawai'I, United States of America
| | - Shaobin Hou
- Department of Microbiology, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States of America
- Advanced Studies of Genomics, Proteomics and Bioinformatics, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States of America
| | - Xuehua Wan
- Department of Microbiology, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States of America
- Advanced Studies of Genomics, Proteomics and Bioinformatics, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States of America
| | - Stuart P. Donachie
- Department of Microbiology, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States of America
- * E-mail:
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Fuciman M, Enriquez MM, Polívka T, Dall'Osto L, Bassi R, Frank HA. Role of xanthophylls in light harvesting in green plants: a spectroscopic investigation of mutant LHCII and Lhcb pigment-protein complexes. J Phys Chem B 2012; 116:3834-49. [PMID: 22372667 DOI: 10.1021/jp210042z] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The spectroscopic properties and energy transfer dynamics of the protein-bound chlorophylls and xanthophylls in monomeric, major LHCII complexes, and minor Lhcb complexes from genetically altered Arabidopsis thaliana plants have been investigated using both steady-state and time-resolved absorption and fluorescence spectroscopic methods. The pigment-protein complexes that were studied contain Chl a, Chl b, and variable amounts of the xanthophylls, zeaxanthin (Z), violaxanthin (V), neoxanthin (N), and lutein (L). The complexes were derived from mutants of plants denoted npq1 (NVL), npq2lut2 (Z), aba4npq1lut2 (V), aba4npq1 (VL), npq1lut2 (NV), and npq2 (LZ). The data reveal specific singlet energy transfer routes and excited state spectra and dynamics that depend on the xanthophyll present in the complex.
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Affiliation(s)
- Marcel Fuciman
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3060, United States
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