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Abstract
Photosynthetic Cyanobacteria and their descendants are the only known organisms capable of oxygenic photosynthesis. Their metabolism permanently changed the Earth’s surface and the evolutionary trajectory of life, but little is known about their evolutionary history. Genomes of the Gloeobacterales, an order of deeply divergent photosynthetic Cyanobacteria, may hold clues about the evolutionary process. However, there are only three published genomes within this order, and it is difficult to make broad inferences based on such little data. Here, I describe five species within the Gloeobacterales retrieved from publicly available databases and examine their photosynthetic gene content and the environments in which Gloeobacterales genomes and 16S rRNA gene sequences are found. The Gloeobacterales contain reduced photosystems and inhabit cold, wet-rock, and low-light environments. They are likely present in low abundances due to their low growth rate. Future searches for Gloeobacterales should target these environments, and samples should be deeply sequenced to capture the low-abundance taxa. Publicly available databases contain undescribed taxa within the Gloeobacterales. However, searching through all available data with current methods is computationally expensive. Therefore, new methods must be developed to search for these and other evolutionarily important taxa. Once identified, these novel photosynthetic Cyanobacteria will help illuminate the origin and evolution of oxygenic photosynthesis. IMPORTANCE Early branching photosynthetic Cyanobacteria such as the Gloeobacterales may provide clues into the evolutionary history of oxygenic photosynthesis, but there are few genomes or cultured taxa from this order. Five new metagenome-assembled genomes suggest that members of the Gloeobacterales all contain reduced photosystems and lack genes associated with thylakoids and circadian rhythms. Their distribution suggests that they may thrive in environments that are marginal for other species, including wet-rock and cold environments. These traits may aid in the discovery and cultivation of novel species in this clade.
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A New Thermophilic Ene-Reductase from the Filamentous Anoxygenic Phototrophic Bacterium Chloroflexus aggregans. Microorganisms 2021; 9:microorganisms9050953. [PMID: 33925162 PMCID: PMC8146883 DOI: 10.3390/microorganisms9050953] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/23/2021] [Accepted: 04/27/2021] [Indexed: 11/25/2022] Open
Abstract
Aiming at expanding the biocatalytic toolbox of ene-reductase enzymes, we decided to explore photosynthetic extremophile microorganisms as unique reservoir of (new) biocatalytic activities. We selected a new thermophilic ene-reductase homologue in Chloroflexus aggregans, a peculiar filamentous bacterium. We report here on the functional and structural characterization of this new enzyme, which we called CaOYE. Produced in high yields in recombinant form, it proved to be a robust biocatalyst showing high thermostability, good solvent tolerance and a wide range of pH optimum. In a preliminary screening, CaOYE displayed a restricted substrate spectrum (with generally lower activities compared to other ene-reductases); however, given the amazing metabolic ductility and versatility of Chloroflexus aggregans, further investigations could pinpoint peculiar chemical activities. X-ray crystal structure has been determined, revealing conserved features of Class III (or thermophilic-like group) of the family of Old Yellow Enzymes: in the crystal packing, the enzyme was found to assemble as dimer even if it behaves as a monomer in solution. The description of CaOYE catalytic properties and crystal structure provides new details useful for enlarging knowledge, development and application of this class of enzymes.
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A phylogenetically novel cyanobacterium most closely related to Gloeobacter. ISME JOURNAL 2020; 14:2142-2152. [PMID: 32424249 PMCID: PMC7368068 DOI: 10.1038/s41396-020-0668-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 04/09/2020] [Accepted: 04/24/2020] [Indexed: 01/01/2023]
Abstract
Clues to the evolutionary steps producing innovations in oxygenic photosynthesis may be preserved in the genomes of organisms phylogenetically placed between non-photosynthetic Vampirovibrionia (formerly Melainabacteria) and the thylakoid-containing Cyanobacteria. However, only two species with published genomes are known to occupy this phylogenetic space, both within the genus Gloeobacter. Here, we describe nearly complete, metagenome-assembled genomes (MAGs) of an uncultured organism phylogenetically placed near Gloeobacter, for which we propose the name Candidatus Aurora vandensis {Au’ro.ra. L. fem. n. aurora, the goddess of the dawn in Roman mythology; van.de’nsis. N.L. fem. adj. vandensis of Lake Vanda, Antarctica}. The MAG of A. vandensis contains homologs of most genes necessary for oxygenic photosynthesis including key reaction center proteins. Many accessory subunits associated with the photosystems in other species either are missing from the MAG or are poorly conserved. The MAG also lacks homologs of genes associated with the pigments phycocyanoerethrin, phycoeretherin and several structural parts of the phycobilisome. Additional characterization of this organism is expected to inform models of the evolution of oxygenic photosynthesis.
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Liu LN. Distribution and dynamics of electron transport complexes in cyanobacterial thylakoid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:256-65. [PMID: 26619924 PMCID: PMC4756276 DOI: 10.1016/j.bbabio.2015.11.010] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 11/17/2015] [Accepted: 11/19/2015] [Indexed: 12/24/2022]
Abstract
The cyanobacterial thylakoid membrane represents a system that can carry out both oxygenic photosynthesis and respiration simultaneously. The organization, interactions and mobility of components of these two electron transport pathways are indispensable to the biosynthesis of thylakoid membrane modules and the optimization of bioenergetic electron flow in response to environmental changes. These are of fundamental importance to the metabolic robustness and plasticity of cyanobacteria. This review summarizes our current knowledge about the distribution and dynamics of electron transport components in cyanobacterial thylakoid membranes. Global understanding of the principles that govern the dynamic regulation of electron transport pathways in nature will provide a framework for the design and synthetic engineering of new bioenergetic machinery to improve photosynthesis and biofuel production. This article is part of a Special Issue entitled: Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux. Cyanobacterial thylakoid membranes carry out both oxygenic photosynthesis and respiration. Electron transport components are located in the thylakoid membrane and functionally coordinate with each other. Distribution and dynamics of electron transport components are physiologically regulated in response to environmental change.
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Affiliation(s)
- Lu-Ning Liu
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, United Kingdom.
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Rast A, Heinz S, Nickelsen J. Biogenesis of thylakoid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:821-30. [PMID: 25615584 DOI: 10.1016/j.bbabio.2015.01.007] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 01/09/2015] [Accepted: 01/15/2015] [Indexed: 12/15/2022]
Abstract
Thylakoids mediate photosynthetic electron transfer and represent one of the most elaborate energy-transducing membrane systems. Despite our detailed knowledge of its structure and function, much remains to be learned about how the machinery is put together. The concerted synthesis and assembly of lipids, proteins and low-molecular-weight cofactors like pigments and transition metal ions require a high level of spatiotemporal coordination. While increasing numbers of assembly factors are being functionally characterized, the principles that govern how thylakoid membrane maturation is organized in space are just starting to emerge. In both cyanobacteria and chloroplasts, distinct production lines for the fabrication of photosynthetic complexes, in particular photosystem II, have been identified. This article is part of a Special Issue entitled: Chloroplast Biogenesis.
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Affiliation(s)
- Anna Rast
- Molekulare Pflanzenwissenschaften, Biozentrum LMU München, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Steffen Heinz
- Molekulare Pflanzenwissenschaften, Biozentrum LMU München, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Jörg Nickelsen
- Molekulare Pflanzenwissenschaften, Biozentrum LMU München, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany.
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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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Satoh S, Mimuro M, Tanaka A. Construction of a phylogenetic tree of photosynthetic prokaryotes based on average similarities of whole genome sequences. PLoS One 2013; 8:e70290. [PMID: 23922968 PMCID: PMC3724816 DOI: 10.1371/journal.pone.0070290] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 06/18/2013] [Indexed: 12/03/2022] Open
Abstract
Phylogenetic trees have been constructed for a wide range of organisms using gene sequence information, especially through the identification of orthologous genes that have been vertically inherited. The number of available complete genome sequences is rapidly increasing, and many tools for construction of genome trees based on whole genome sequences have been proposed. However, development of a reasonable method of using complete genome sequences for construction of phylogenetic trees has not been established. We have developed a method for construction of phylogenetic trees based on the average sequence similarities of whole genome sequences. We used this method to examine the phylogeny of 115 photosynthetic prokaryotes, i.e., cyanobacteria, Chlorobi, proteobacteria, Chloroflexi, Firmicutes and nonphotosynthetic organisms including Archaea. Although the bootstrap values for the branching order of phyla were low, probably due to lateral gene transfer and saturated mutation, the obtained tree was largely consistent with the previously reported phylogenetic trees, indicating that this method is a robust alternative to traditional phylogenetic methods.
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Affiliation(s)
- Soichirou Satoh
- Graduate School of Life and Environmental Science, Kyoto Prefectural University, Kyoto, Japan
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | - Mamoru Mimuro
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Ayumi Tanaka
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
- CREST, Japan Science and Technology Agency, Sapporo, Japan
- * E-mail:
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Mareš J, Hrouzek P, Kaňa R, Ventura S, Strunecký O, Komárek J. The Primitive Thylakoid-Less Cyanobacterium Gloeobacter Is a Common Rock-Dwelling Organism. PLoS One 2013; 8:e66323. [PMID: 23823729 PMCID: PMC3688883 DOI: 10.1371/journal.pone.0066323] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2013] [Accepted: 05/03/2013] [Indexed: 01/09/2023] Open
Abstract
Cyanobacteria are an ancient group of photosynthetic prokaryotes, which are significant in biogeochemical cycles. The most primitive among living cyanobacteria, Gloeobacter violaceus, shows a unique ancestral cell organization with a complete absence of inner membranes (thylakoids) and an uncommon structure of the photosynthetic apparatus. Numerous phylogenetic papers proved its basal position among all of the organisms and organelles capable of plant-like photosynthesis (i.e., cyanobacteria, chloroplasts of algae and plants). Hence, G. violaceus has become one of the key species in evolutionary study of photosynthetic life. It also numbers among the most widely used organisms in experimental photosynthesis research. Except for a few related culture isolates, there has been little data on the actual biology of Gloeobacter, being relegated to an "evolutionary curiosity" with an enigmatic identity. Here we show that members of the genus Gloeobacter probably are common rock-dwelling cyanobacteria. On the basis of morphological, ultrastructural, pigment, and phylogenetic comparisons of available Gloeobacter strains, as well as on the basis of three new independent isolates and historical type specimen, we have produced strong evidence as to the close relationship of Gloeobacter to a long known rock-dwelling cyanobacterial morphospecies Aphanothece caldariorum. Our results bring new clues to solving the 40 year old puzzle of the true biological identity of Gloeobacter violaceus, a model organism with a high value in several biological disciplines. A probable broader distribution of Gloeobacter in common wet-rock habitats worldwide is suggested by our data, and its ecological meaning is discussed taking into consideration the background of cyanobacterial evolution. We provide observations of previously unknown genetic variability and phenotypic plasticity, which we expect to be utilized by experimental and evolutionary researchers worldwide.
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Affiliation(s)
- Jan Mareš
- Institute of Botany ASCR, Centre for Phycology, Třeboň, Czech Republic
- Department of Botany, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Pavel Hrouzek
- Institute of Microbiology ASCR, Department of Autotrophic Microorganisms - ALGATECH, Třeboň, Czech Republic
| | - Radek Kaňa
- Institute of Microbiology ASCR, Department of Autotrophic Microorganisms - ALGATECH, Třeboň, Czech Republic
| | - Stefano Ventura
- CNR-ISE Istituto per lo Studio degli Ecosistemi, Sesto Fiorentino, Italy
| | - Otakar Strunecký
- Institute of Botany ASCR, Centre for Phycology, Třeboň, Czech Republic
- Centre for Polar Ecology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Jiří Komárek
- Institute of Botany ASCR, Centre for Phycology, Třeboň, Czech Republic
- Department of Botany, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
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9
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Photosystem trap energies and spectrally-dependent energy-storage efficiencies in the Chl d-utilizing cyanobacterium, Acaryochloris marina. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1827:255-65. [DOI: 10.1016/j.bbabio.2012.11.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 10/08/2012] [Accepted: 11/02/2012] [Indexed: 12/27/2022]
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10
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Nickelsen J, Rengstl B. Photosystem II assembly: from cyanobacteria to plants. ANNUAL REVIEW OF PLANT BIOLOGY 2013; 64:609-35. [PMID: 23451783 DOI: 10.1146/annurev-arplant-050312-120124] [Citation(s) in RCA: 220] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Photosystem II (PSII) is an integral-membrane, multisubunit complex that initiates electron flow in oxygenic photosynthesis. The biogenesis of this complex machine involves the concerted assembly of at least 20 different polypeptides as well as the incorporation of a variety of inorganic and organic cofactors. Many factors have recently been identified that constitute an integrative network mediating the stepwise assembly of PSII components. One recurring theme is the subcellular organization of the assembly process in specialized membranes that form distinct biogenesis centers. Here, we review our current knowledge of the molecular components and events involved in PSII assembly and their high degree of evolutionary conservation.
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Affiliation(s)
- Jörg Nickelsen
- Molekulare Pflanzenwissenschaften, Biozentrum Ludwig-Maximilians-Universität München, 82152 Planegg-Martinsried, Germany.
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11
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Bernát G, Schreiber U, Sendtko E, Stadnichuk IN, Rexroth S, Rögner M, Koenig F. Unique properties vs. common themes: the atypical cyanobacterium Gloeobacter violaceus PCC 7421 is capable of state transitions and blue-light-induced fluorescence quenching. PLANT & CELL PHYSIOLOGY 2012; 53:528-542. [PMID: 22302714 DOI: 10.1093/pcp/pcs009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The atypical unicellular cyanobacterium Gloeobacter violaceus PCC 7421, which diverged very early during the evolution of cyanobacteria, can be regarded as a key organism for understanding many structural, functional, regulatory and evolutionary aspects of oxygenic photosynthesis. In the present work, the performance of two basic photosynthetic adaptation/protection mechanisms, common to all other oxygenic photoautrophs, had been challenged in this ancient cyanobacterium which lacks thylakoid membranes: state transitions and non-photochemical fluorescence quenching. Both low temperature fluorescence spectra and room temperature fluorescence transients show that G. violaceus is capable of performing state transitions similar to evolutionarily more recent cyanobacteria, being in state 2 in darkness and in state 1 upon illumination by weak blue or far-red light. Compared with state 2, variable fluorescence yield in state 1 is strongly enhanced (almost 80%), while the functional absorption cross-section of PSII is only increased by 8%. In contrast to weak blue light, which enhances fluorescence yield via state 1 formation, strong blue light reversibly quenches Chl fluorescence in G. violaceus. This strongly suggests regulated heat dissipation which is triggered by the orange carotenoid protein whose presence was directly proven by immunoblotting and mass spectrometry in this primordial cyanobacterium. The results are discussed in the framework of cyanobacterial evolution.
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Affiliation(s)
- Gábor Bernát
- Plant Biochemistry, Ruhr-University Bochum, D-44801 Bochum, Germany.
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12
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Vothknecht UC, Otters S, Hennig R, Schneider D. Vipp1: a very important protein in plastids?! JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:1699-712. [PMID: 22131161 DOI: 10.1093/jxb/err357] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
As a key feature in oxygenic photosynthesis, thylakoid membranes play an essential role in the physiology of plants, algae, and cyanobacteria. Despite their importance in the process of oxygenic photosynthesis, their biogenesis has remained a mystery to the present day. A decade ago, vesicle-inducing protein in plastids 1 (Vipp1) was described to be involved in thylakoid membrane formation in chloroplasts and cyanobacteria. Most follow-up studies clearly linked Vipp1 to membranes and Vipp1 interactions as well as the defects observed after Vipp1 depletion in chloroplasts and cyanobacteria indicate that Vipp1 directly binds to membranes, locally stabilizes bilayer structures, and thereby retains membrane integrity. Here current knowledge about the structure and function of Vipp1 is summarized with a special focus on its relationship to the bacterial phage shock protein A (PspA), as both proteins share a common origin and appear to have retained many similarities in structure and function.
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Affiliation(s)
- Ute C Vothknecht
- Department of Biology I, LMU Munich, D-82152 Planegg-Martinsried, Germany.
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13
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Evolution of a divinyl chlorophyll-based photosystem in Prochlorococcus. Proc Natl Acad Sci U S A 2011; 108:18014-9. [PMID: 22006316 DOI: 10.1073/pnas.1107590108] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Acquisition of new photosynthetic pigments has been a crucial process for the evolution of photosynthesis and photosynthetic organisms. In this process, pigment-binding proteins must evolve to fit new pigments. Prochlorococcus is a unique photosynthetic organism that uses divinyl chlorophyll (DVChl) instead of monovinyl chlorophyll. However, cyanobacterial mutants that accumulate DVChl immediately die even under medium-light conditions, suggesting that chlorophyll (Chl)-binding proteins had to evolve to fit to DVChl concurrently with Prochlorococcus evolution. To elucidate the coevolutionary process of Chl and Chl-binding proteins during the establishment of DVChl-based photosystems, we first compared the amino acid sequences of Chl-binding proteins in Prochlorococcus with those in other photosynthetic organisms. Two amino acid residues of the D1 protein, V205 and G282, are conserved in monovinyl chlorophyll-based photosystems; however, in Prochlorococcus, they are substituted with M205 and C282, respectively. According to the solved photosystem II structure, these amino acids are not involved in Chl binding. To mimic Prochlorococcus, V205 was mutated to M205 in the D1 protein from Synechocystis sp. PCC6803 and Synechocystis dvr mutant was transformed with this construct. Although these transgenic cells could not grow under high-light conditions, they acquired light tolerance and grew under medium-light conditions, whereas untransformed dvr mutants could not survive. Substitution of G282 for C282 contributed additional light tolerance, suggesting that the amino acid substitutions in the D1 protein played an essential role in the development of DVChl-based photosystems. Here, we discuss the coevolution of a photosynthetic pigment and its binding protein.
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14
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Chen M, Blankenship RE. Expanding the solar spectrum used by photosynthesis. TRENDS IN PLANT SCIENCE 2011; 16:427-31. [PMID: 21493120 DOI: 10.1016/j.tplants.2011.03.011] [Citation(s) in RCA: 192] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 03/11/2011] [Accepted: 03/11/2011] [Indexed: 05/03/2023]
Abstract
A limiting factor for photosynthetic organisms is their light-harvesting efficiency, that is the efficiency of their conversion of light energy to chemical energy. Small modifications or variations of chlorophylls allow photosynthetic organisms to harvest sunlight at different wavelengths. Oxygenic photosynthetic organisms usually utilize only the visible portion of the solar spectrum. The cyanobacterium Acaryochloris marina carries out oxygenic photosynthesis but contains mostly chlorophyll d and only traces of chlorophyll a. Chlorophyll d provides a potential selective advantage because it enables Acaryochloris to use infrared light (700-750 nm) that is not absorbed by chlorophyll a. Recently, an even more red-shifted chlorophyll termed chlorophyll f has been reported. Here, we discuss using modified chlorophylls to extend the spectral region of light that drives photosynthetic organisms.
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Affiliation(s)
- Min Chen
- School of Biological Sciences, University of Sydney, Sydney, NSW 2006, Australia
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15
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Rexroth S, Mullineaux CW, Ellinger D, Sendtko E, Rögner M, Koenig F. The plasma membrane of the cyanobacterium Gloeobacter violaceus contains segregated bioenergetic domains. THE PLANT CELL 2011; 23:2379-90. [PMID: 21642550 PMCID: PMC3160022 DOI: 10.1105/tpc.111.085779] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 04/01/2011] [Accepted: 05/14/2011] [Indexed: 05/18/2023]
Abstract
The light reactions of oxygenic photosynthesis almost invariably take place in the thylakoid membranes, a highly specialized internal membrane system located in the stroma of chloroplasts and the cytoplasm of cyanobacteria. The only known exception is the primordial cyanobacterium Gloeobacter violaceus, which evolved before the appearance of thylakoids and harbors the photosynthetic complexes in the plasma membrane. Thus, studies on G. violaceus not only shed light on the evolutionary origin and the functional advantages of thylakoid membranes but also might include insights regarding thylakoid formation during chloroplast differentiation. Based on biochemical isolation and direct in vivo characterization, we report here structural and functional domains in the cytoplasmic membrane of a cyanobacterium. Although G. violaceus has no internal membranes, it does have localized domains with apparently specialized functions in its plasma membrane, in which both the photosynthetic and the respiratory complexes are concentrated. These bioenergetic domains can be visualized by confocal microscopy, and they can be isolated by a simple procedure. Proteomic analysis of these domains indicates their physiological function and suggests a protein sorting mechanism via interaction with membrane-intrinsic terpenoids. Based on these results, we propose specialized domains in the plasma membrane as evolutionary precursors of thylakoids.
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Affiliation(s)
- Sascha Rexroth
- Plant Biochemistry, Ruhr-University Bochum, 44780 Bochum, Germany.
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Nakamura A, Suzawa T, Kato Y, Watanabe T. Species Dependence of the Redox Potential of the Primary Electron Donor P700 in Photosystem I of Oxygenic Photosynthetic Organisms Revealed by Spectroelectrochemistry. ACTA ACUST UNITED AC 2011; 52:815-23. [DOI: 10.1093/pcp/pcr034] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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17
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Allen JP, Williams JC. The evolutionary pathway from anoxygenic to oxygenic photosynthesis examined by comparison of the properties of photosystem II and bacterial reaction centers. PHOTOSYNTHESIS RESEARCH 2011; 107:59-69. [PMID: 20449659 DOI: 10.1007/s11120-010-9552-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Accepted: 04/05/2010] [Indexed: 05/29/2023]
Abstract
In photosynthetic organisms, such as purple bacteria, cyanobacteria, and plants, light is captured and converted into energy to create energy-rich compounds. The primary process of energy conversion involves the transfer of electrons from an excited donor molecule to a series of electron acceptors in pigment-protein complexes. Two of these complexes, the bacterial reaction center and photosystem II, are evolutionarily related and structurally similar. However, only photosystem II is capable of performing the unique reaction of water oxidation. An understanding of the evolutionary process that lead to the development of oxygenic photosynthesis can be found by comparison of these two complexes. In this review, we summarize how insight is being gained by examination of the differences in critical functional properties of these complexes and by experimental efforts to alter pigment-protein interactions of the bacterial reaction center in order to enable it to perform reactions, such as amino acid and metal oxidation, observable in photosystem II.
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Affiliation(s)
- J P Allen
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-1604, USA.
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Pascual MB, Mata-Cabana A, Florencio FJ, Lindahl M, Cejudo FJ. Overoxidation of 2-Cys peroxiredoxin in prokaryotes: cyanobacterial 2-Cys peroxiredoxins sensitive to oxidative stress. J Biol Chem 2010; 285:34485-92. [PMID: 20736168 PMCID: PMC2966063 DOI: 10.1074/jbc.m110.160465] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 08/16/2010] [Indexed: 12/29/2022] Open
Abstract
In eukaryotic organisms, hydrogen peroxide has a dual effect; it is potentially toxic for the cell but also has an important signaling activity. According to the previously proposed floodgate hypothesis, the signaling activity of hydrogen peroxide in eukaryotes requires a transient increase in its concentration, which is due to the inactivation by overoxidation of 2-Cys peroxiredoxin (2-Cys Prx). Sensitivity to overoxidation depends on the structural GGLG and YF motifs present in eukaryotic 2-Cys Prxs and is believed to be absent from prokaryotic enzymes, thus representing a paradoxical gain of function exclusive to eukaryotic organisms. Here we show that 2-Cys Prxs from several prokaryotic organisms, including cyanobacteria, contain the GG(L/V/I)G and YF motifs characteristic of sensitive enzymes. In search of the existence of overoxidation-sensitive 2-Cys Prxs in prokaryotes, we have analyzed the sensitivity to overoxidation of 2-Cys Prxs from two cyanobacterial strains, Anabaena sp. PCC7120 and Synechocystis sp. PCC6803. In vitro analysis of wild type and mutant variants of the Anabaena 2-Cys Prx showed that this enzyme is overoxidized at the peroxidatic cysteine residue, thus constituting an exception among prokaryotes. Moreover, the 2-Cys Prx from Anabaena is readily and reversibly overoxidized in vivo in response to high light and hydrogen peroxide, showing higher sensitivity to overoxidation than the Synechocystis enzyme. These cyanobacterial strains have different strategies to cope with hydrogen peroxide. While Synechocystis has low content of less sensitive 2-Cys Prx and high catalase activity, Anabaena contains abundant and sensitive 2-Cys Prx, but low catalase activity, which is remarkably similar to the chloroplast system.
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Affiliation(s)
- María B Pascual
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and Consejo Superior de Investigaciones Científicas, 41092 Sevilla, Spain
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Schliep M, Crossett B, Willows RD, Chen M. 18O labeling of chlorophyll d in Acaryochloris marina reveals that chlorophyll a and molecular oxygen are precursors. J Biol Chem 2010; 285:28450-6. [PMID: 20610399 DOI: 10.1074/jbc.m110.146753] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The cyanobacterium Acaryochloris marina was cultured in the presence of either H(2)(18)O or (18)O(2), and the newly synthesized chlorophylls (Chl a and Chl d) were isolated using high performance liquid chromatography and analyzed by mass spectroscopy. In the presence of H(2)(18)O, newly synthesized Chl a and d, both incorporated up to four isotopic (18)O atoms. Time course H(2)(18)O labeling experiments showed incorporation of isotopic (18)O atoms originating from H(2)(18)O into Chl a, with over 90% of Chl a (18)O-labeled at 48 h. The incorporation of isotopic (18)O atoms into Chl d upon incubation in H(2)(18)O was slower compared with Chl a with approximately 50% (18)O-labeled Chl d at 115 h. The rapid turnover of newly synthesized Chl a suggested that Chl a is the direct biosynthetic precursor of Chl d. In the presence of (18)O(2) gas, one isotopic (18)O atom was incorporated into Chl a with approximately the same kinetic incorporation rate observed in the H(2)(18)O labeling experiment, reaching over 90% labeling intensity at 48 h. The incorporation of two isotopic (18)O atoms derived from molecular oxygen ((18)O(2)) was observed in the extracted Chl d, and the percentage of double isotopic (18)O-labeled Chl d increased in parallel with the decrease of non-isotopic-labeled Chl d. This clearly indicated that the oxygen atom in the C3(1)-formyl group of Chl d is derived from dioxygen via an oxygenase-type reaction mechanism.
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Affiliation(s)
- Martin Schliep
- Schools of Biological Sciences, The University of Sydney, Sydney, New South Wales 2006, Australia
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20
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Gao B, Boeglin WE, Brash AR. Omega-3 fatty acids are oxygenated at the n-7 carbon by the lipoxygenase domain of a fusion protein in the cyanobacterium Acaryochloris marina. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1801:58-63. [PMID: 19786119 DOI: 10.1016/j.bbalip.2009.09.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Revised: 08/31/2009] [Accepted: 09/14/2009] [Indexed: 11/30/2022]
Abstract
Lipoxygenases (LOX) are found in most organisms that contain polyunsaturated fatty acids, usually existing as individual genes although occasionally encoded as a fusion protein with a catalase-related hemoprotein. Such a fusion protein occurs in the cyanobacterium Acaryochloris marina and herein we report the novel catalytic activity of its LOX domain. The full-length protein and the C-terminal LOX domain were expressed in Escherichia coli, and the catalytic activities characterized by UV, HPLC, GC-MS, and CD. All omega-3 polyunsaturates were oxygenated by the LOX domain at the n-7 position and with R stereospecificity: alpha-linolenic and the most abundant fatty acid in A. marina, stearidonic acid (C18.4omega3), are converted to the corresponding 12R-hydroperoxides, eicosapentaenoic acid to its 14R-hydroperoxide, and docosahexaenoic acid to its 16R-hydroperoxide. Omega-6 polyunsaturates were oxygenated at the n-10 position, forming 9R-hydroperoxy-octadecadienoic acid from linoleic acid and 11R-hydroperoxy-eicosatetraenoic acid from arachidonic acid. The metabolic transformation of stearidonic acid by the full-length fusion protein entails its 12R oxygenation with subsequent conversion by the catalase-related domain to a novel allene epoxide, a likely precursor of cyclopentenone fatty acids or other signaling molecules (Gao et al, J. Biol. Chem. 284:22087-98, 2009). Although omega-3 fatty acids and lipoxygenases are of widespread occurrence, this appears to be the first description of a LOX-catalyzed oxygenation that specifically utilizes the terminal pentadiene of omega-3 fatty acids.
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Affiliation(s)
- Benlian Gao
- Department of Pharmacology, and the Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, USA
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21
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Gao B, Boeglin WE, Zheng Y, Schneider C, Brash AR. Evidence for an ionic intermediate in the transformation of fatty acid hydroperoxide by a catalase-related allene oxide synthase from the Cyanobacterium Acaryochloris marina. J Biol Chem 2009; 284:22087-22098. [PMID: 19531485 DOI: 10.1074/jbc.m109.013151] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Allene oxides are reactive epoxides biosynthesized from fatty acid hydroperoxides by specialized cytochrome P450s or by catalase-related hemoproteins. Here we cloned, expressed, and characterized a gene encoding a lipoxygenase-catalase/peroxidase fusion protein from Acaryochloris marina. We identified novel allene oxide synthase (AOS) activity and a by-product that provides evidence of the reaction mechanism. The fatty acids 18.4omega3 and 18.3omega3 are oxygenated to the 12R-hydroperoxide by the lipoxygenase domain and converted to the corresponding 12R,13-epoxy allene oxide by the catalase-related domain. Linoleic acid is oxygenated to its 9R-hydroperoxide and then, surprisingly, converted approximately 70% to an epoxyalcohol identified spectroscopically and by chemical synthesis as 9R,10S-epoxy-13S-hydroxyoctadeca-11E-enoic acid and only approximately 30% to the 9R,10-epoxy allene oxide. Experiments using oxygen-18-labeled 9R-hydroperoxide substrate and enzyme incubations conducted in H2(18)O indicated that approximately 72% of the oxygen in the epoxyalcohol 13S-hydroxyl arises from water, a finding that points to an ionic intermediate (epoxy allylic carbocation) during catalysis. AOS and epoxyalcohol synthase activities are mechanistically related, with a reacting intermediate undergoing a net hydrogen abstraction or hydroxylation, respectively. The existence of epoxy allylic carbocations in fatty acid transformations is widely implicated although for AOS reactions, without direct experimental support. Our findings place together in strong association the reactions of allene oxide synthesis and an ionic reaction intermediate in the AOS-catalyzed transformation.
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Affiliation(s)
- Benlian Gao
- Department of Pharmacology and the Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232
| | - William E Boeglin
- Department of Pharmacology and the Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232
| | - Yuxiang Zheng
- Department of Pharmacology and the Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232
| | - Claus Schneider
- Department of Pharmacology and the Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232
| | - Alan R Brash
- Department of Pharmacology and the Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232
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Raven JA. Functional evolution of photochemical energy transformations in oxygen-producing organisms. FUNCTIONAL PLANT BIOLOGY : FPB 2009; 36:505-515. [PMID: 32688665 DOI: 10.1071/fp09087] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Accepted: 04/21/2009] [Indexed: 05/21/2023]
Abstract
Chlorophyll a is the photochemical agent accounting for most oxygenic photosynthesis, that is, over 99.9% of photosynthetic primary activity on Earth. The spectral and energetic properties of chlorophyll a can, at least in part, be rationalised in terms of the solar spectral output and the energetics of oxygen production and carbon dioxide reduction with two photochemical reactions. The long wavelength limit on in vivo chlorophyll a absorption is probably close to the energetic limit: longer wavelengths could not support a high rate and efficiency of oxygenic photosynthesis. Retinal, a β-carotene derivative that is the chromophore of rhodopsin, acts not only as a sensory pigment, but also as an ion-pumping photochemical transducer. Both sensory and energy-transforming rhodopsins occur in oxygenic phototrophs, although the extent of expression and the function of the latter are not well understood.
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Affiliation(s)
- John A Raven
- Division of Plant Sciences, University of Dundee at SCRI, Invergowrie, Dundee DD2 5DA, UK. Email
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