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Saga Y, Takahashi N, Miyatake T, Tamiaki H. Amphiphilic zinc bacteriochlorophyll a derivatives that function as artificial energy acceptors in photosynthetic antenna complexes chlorosomes of the green sulfur photosynthetic bacterium Chlorobaculum limnaeum. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2017.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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2
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Saga Y, Yoshida N, Yamada S, Mizoguchi T, Tamiaki H. Biosynthesis of unnatural glycolipids possessing diyne moiety in the acyl chain in the green sulfur photosynthetic bacterium Chlorobaculum tepidum grown by supplementation of 10,12-heptadecadiynic acid. Biochem Biophys Rep 2017; 9:42-46. [PMID: 28955987 PMCID: PMC5614547 DOI: 10.1016/j.bbrep.2016.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 11/09/2016] [Accepted: 11/12/2016] [Indexed: 12/04/2022] Open
Abstract
Unnatural glycolipids possessing the diyne moiety in their acyl groups were successfully biosynthesized in the green sulfur photosynthetic bacterium Chlorobaculum (Cba.) tepidum by cultivation with supplementation of 10,12-heptadecadiynic acid. Monogalactosyldiacylglycerol (MGDG) and rhamnosylgalactosyldiacylglycerol (RGDG) esterified with one 10,12-heptadecadiynic acid were primarily formed in the cells, and small amounts of glycolipids esterified with the two unnatural fatty acids can also be detected. The relative ratio of these unnatural glycolipids occupied in the total glycolipids was estimated to be 49% based on HPLC analysis using a evaporative light scattering detector. These results indicate that the acyl groups in glycolipids, which play important roles in the formation of extramembranous antenna complexes called chlorosomes, can be modified in vivo by cultivation of green sulfur photosynthetic bacteria with exogenous synthetic fatty acids. Visible absorption and circular dichroism spectra of Cba. tepidum containing the unnatural glycolipids demonstrated the formation of chlorosomes, indicating that the unnatural glycolipids in this study did not interfere with the biogenesis of chlorosomes. Novel glycolipids possessing a diyne moiety in the acyl chain were biosynthesized. Supplemental fatty acids were used in the biosynthesis of glycolipids in the photosynthetic bacterium. The novel glycolipids did not inhibit the formation of photosynthetic antenna complexes.
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Affiliation(s)
- Yoshitaka Saga
- Department of Chemistry, Faculty of Science and Engineering, Kindai University, Higashi-Osaka, Osaka 577-8502, Japan.,PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan
| | - Nozomi Yoshida
- Department of Chemistry, Faculty of Science and Engineering, Kindai University, Higashi-Osaka, Osaka 577-8502, Japan
| | - Shota Yamada
- Department of Chemistry, Faculty of Science and Engineering, Kindai University, Higashi-Osaka, Osaka 577-8502, Japan
| | - Tadashi Mizoguchi
- Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Hitoshi Tamiaki
- Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
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Thweatt JL, Ferlez BH, Golbeck JH, Bryant DA. BciD Is a Radical S-Adenosyl-l-methionine (SAM) Enzyme That Completes Bacteriochlorophyllide e Biosynthesis by Oxidizing a Methyl Group into a Formyl Group at C-7. J Biol Chem 2016; 292:1361-1373. [PMID: 27994052 DOI: 10.1074/jbc.m116.767665] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 12/12/2016] [Indexed: 01/05/2023] Open
Abstract
Green bacteria are chlorophotorophs that synthesize bacteriochlorophyll (BChl) c, d, or e, which assemble into supramolecular, nanotubular structures in large light-harvesting structures called chlorosomes. The biosynthetic pathways of these chlorophylls are known except for one reaction. Null mutants of bciD, which encodes a putative radical S-adenosyl-l-methionine (SAM) protein, are unable to synthesize BChl e but accumulate BChl c; however, it is unknown whether BciD is sufficient to convert BChl c (or its precursor, bacteriochlorophyllide (BChlide) c) into BChl e (or BChlide e). To determine the function of BciD, we expressed the bciD gene of Chlorobaculum limnaeum strain DSMZ 1677T in Escherichia coli and purified the enzyme under anoxic conditions. Electron paramagnetic resonance spectroscopy of BciD indicated that it contains a single [4Fe-4S] cluster. In assays containing SAM, BChlide c or d, and sodium dithionite, BciD catalyzed the conversion of SAM into 5'-deoxyadenosine and BChlide c or d into BChlide e or f, respectively. Our analyses also identified intermediates that are proposed to be 71-OH-BChlide c and d Thus, BciD is a radical SAM enzyme that converts the methyl group of BChlide c or d into the formyl group of BChlide e or f This probably occurs by a mechanism involving consecutive hydroxylation reactions of the C-7 methyl group to form a geminal diol intermediate, which spontaneously dehydrates to produce the final products, BChlide e or BChlide f The demonstration that BciD is sufficient to catalyze the conversion of BChlide c into BChlide e completes the biosynthetic pathways for all "Chlorobium chlorophylls."
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Affiliation(s)
| | - Bryan H Ferlez
- From the Departments of Biochemistry and Molecular Biology and
| | - John H Golbeck
- From the Departments of Biochemistry and Molecular Biology and.,Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802 and
| | - Donald A Bryant
- From the Departments of Biochemistry and Molecular Biology and .,the Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717
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Jendrny M, Aartsma TJ, Köhler J. Insights into the excitonic states of individual chlorosomes from Chlorobaculum tepidum. Biophys J 2014; 106:1921-7. [PMID: 24806924 DOI: 10.1016/j.bpj.2014.03.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 02/26/2014] [Accepted: 03/14/2014] [Indexed: 11/16/2022] Open
Abstract
Green-sulfur bacteria have evolved a unique light-harvesting apparatus, the chlorosome, by which it is perfectly adapted to thrive photosynthetically under extremely low light conditions. We have used single-particle, optical spectroscopy to study the structure-function relationship of chlorosomes each of which incorporates hundreds of thousands of self-assembled bacteriochlorophyll (BChl) molecules. The electronically excited states of these molecular assemblies are described as Frenkel excitons whose photophysical properties depend crucially on the mutual arrangement of the pigments. The signature of these Frenkel excitons and its relation to the supramolecular organization of the chlorosome becomes accessible by optical spectroscopy. Because subtle spectral features get obscured by ensemble averaging, we have studied individual chlorosomes from wild-type Chlorobaculum tepidum by polarization-resolved fluorescence-excitation spectroscopy. This approach minimizes the inherent sample heterogeneity and allows us to reveal properties of the exciton states without ensemble averaging. The results are compared with predictions from computer simulations of various models of the supramolecular organization of the BChl monomers. We find that the photophysical properties of individual chlorosomes from wild-type Chlorobaculum tepidum are consistent with a (multiwall) helical arrangement of syn-anti stacked BChl molecules in cylinders and/or spirals of different size.
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Affiliation(s)
- Marc Jendrny
- Experimental Physics IV and Bayreuth Institute of Macromolecular Research (BIMF), Universität Bayreuth, Universitätsstr. 30, Bayreuth, Germany
| | - Thijs J Aartsma
- Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, Leiden, The Netherlands
| | - Jürgen Köhler
- Experimental Physics IV and Bayreuth Institute of Macromolecular Research (BIMF), Universität Bayreuth, Universitätsstr. 30, Bayreuth, Germany.
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Saga Y, Saiki T, Takahashi N, Shibata Y, Tamiaki H. Scrambled Self-Assembly of Bacteriochlorophyllscandein Aqueous Triton X-100 Micelles. Photochem Photobiol 2013; 90:552-9. [DOI: 10.1111/php.12219] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Accepted: 11/28/2013] [Indexed: 01/13/2023]
Affiliation(s)
- Yoshitaka Saga
- Department of Chemistry; Faculty of Science and Engineering; Kinki University; Higashi-Osaka Japan
| | - Tatsuya Saiki
- Department of Chemistry; Faculty of Science and Engineering; Kinki University; Higashi-Osaka Japan
| | - Naoya Takahashi
- Department of Chemistry; Faculty of Science and Engineering; Kinki University; Higashi-Osaka Japan
| | - Yutaka Shibata
- Department of Chemistry; Graduate School of Science; Tohoku University; Sendai Japan
| | - Hitoshi Tamiaki
- Graduate School of Life Sciences; Ritsumeikan University; Kusatsu Japan
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6
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Numata M, Takayama M, Shoji S, Tamiaki H. Microflow-driven Temporal Self-assembly of Amphiphilic Molecules. CHEM LETT 2012. [DOI: 10.1246/cl.2012.1689] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Munenori Numata
- Department of Biomolecular Chemistry, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University
| | - Momoko Takayama
- Department of Biomolecular Chemistry, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University
| | - Sunao Shoji
- Graduate School of Life Sciences, Ritsumeikan University
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Shoji S, Hashishin T, Tamiaki H. Construction of Chlorosomal Rod Self-Aggregates in the Solid State on Any Substrates from Synthetic Chlorophyll Derivatives Possessing an Oligomethylene Chain at the 17-Propionate Residue. Chemistry 2012; 18:13331-41. [DOI: 10.1002/chem.201201935] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Indexed: 11/09/2022]
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A seventh bacterial chlorophyll driving a large light-harvesting antenna. Sci Rep 2012; 2:671. [PMID: 22993696 PMCID: PMC3445912 DOI: 10.1038/srep00671] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 09/03/2012] [Indexed: 11/21/2022] Open
Abstract
The discovery of new chlorophyllous pigments would provide greater understanding of the mechanisms and evolution of photosynthesis. Bacteriochlorophyll f has never been observed in nature, although this name was proposed ~40 years ago based on structurally related compounds. We constructed a bacteriochlorophyll f–accumulating mutant of the green sulfur bacterium Chlorobaculum limnaeum, which originally produced bacteriochlorophyll e, by knocking out the bchU gene encoding C-20 methyltransferase based on natural transformation. This novel pigment self-aggregates in an in vivo light-harvesting antenna, the chlorosome, and exhibits a Qy peak of 705 nm, more blue-shifted than any other chlorosome reported so far; the peak overlaps the maximum (~700 nm) of the solar photon flux spectrum. Bacteriochlorophyll f chlorosomes can transfer light energy from core aggregated pigments to another bacteriochlorophyll in the chlorosomal envelope across an energy gap of ~100 nm, and is thus a promising material for development of new bioenergy applications.
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Nishimori R, Mizoguchi T, Tamiaki H, Kashimura S, Saga Y. Biosynthesis of Unnatural Bacteriochlorophyll c Derivatives Esterified with α,ω-Diols in the Green Sulfur Photosynthetic Bacterium Chlorobaculum tepidum. Biochemistry 2011; 50:7756-64. [DOI: 10.1021/bi200994h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Risato Nishimori
- Department of Chemistry, Faculty
of Science and Engineering, Kinki University, Higashi-Osaka, Osaka 577-8502, Japan
| | - Tadashi Mizoguchi
- Department of Bioscience and
Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Hitoshi Tamiaki
- Department of Bioscience and
Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Shigenori Kashimura
- Department of Chemistry, Faculty
of Science and Engineering, Kinki University, Higashi-Osaka, Osaka 577-8502, Japan
| | - Yoshitaka Saga
- Department of Chemistry, Faculty
of Science and Engineering, Kinki University, Higashi-Osaka, Osaka 577-8502, Japan
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11
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Kitagawa Y, Segawa H, Ishii K. Magneto-Chiral Dichroism of Organic Compounds. Angew Chem Int Ed Engl 2011; 50:9133-6. [DOI: 10.1002/anie.201101809] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 05/18/2011] [Indexed: 11/09/2022]
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Liu Z, Bryant DA. Identification of a gene essential for the first committed step in the biosynthesis of bacteriochlorophyll c. J Biol Chem 2011; 286:22393-402. [PMID: 21550979 DOI: 10.1074/jbc.m111.249433] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bacteriochlorophylls (BChls) c, d, and e are the major chlorophylls in chlorosomes, which are the largest and one of the most efficient antennae produced by chlorophototrophic organisms. In the biosynthesis of these three BChls, a C-13(2)-methylcarboxyl group found in all other chlorophylls (Chls) must be removed. This reaction is postulated to be the first committed step in the synthesis of these BChls. Analyses of gene neighborhoods of (B)Chl biosynthesis genes and distribution patterns in organisms producing chlorosomes helped to identify a gene (bciC) that appeared to be a good candidate to produce the enzyme involved in this biochemical reaction. To confirm that this was the case, a deletion mutant of an open reading frame orthologous to bciC, CT1077, was constructed in Chlorobaculum tepidum, a genetically tractible green sulfur bacterium. The CT1077 deletion mutant was unable to synthesize BChl c but still synthesized BChl a and Chl a. The deletion mutant accumulated large amounts of various (bacterio)pheophorbides, all of which still had C-13(2)-methylcarboxyl groups. A C. tepidum strain in which CT1077 was replaced by an orthologous gene, Cabther_B0081 [corrected] from "Candidatus Chloracidobacterium thermophilum" was constructed. Although the product of Cabther_B0081 [corrected] was only 28% identical to the product of CT1077, this strain synthesized BChl c, BChl a, and Chl a in amounts similar to wild-type C. tepidum cells. To indicate their roles in the first committed step of BChl c, d, and e biosynthesis, open reading frames CT1077 and Cabther_B0081 [corrected] have been redesignated bciC. The potential mechanism by which BciC removes the C-13(2)-methylcarboxyl moiety of chlorophyllide a is discussed.
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Affiliation(s)
- Zhenfeng Liu
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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Tamiaki H, Komada J, Kunieda M, Fukai K, Yoshitomi T, Harada J, Mizoguchi T. In vitro synthesis and characterization of bacteriochlorophyll-f and its absence in bacteriochlorophyll-e producing organisms. PHOTOSYNTHESIS RESEARCH 2011; 107:133-138. [PMID: 21161597 DOI: 10.1007/s11120-010-9603-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 12/01/2010] [Indexed: 05/30/2023]
Abstract
Bacteriochlorophyll(BChl)-f which has not yet been found in natural phototrophs was prepared by chemically modifying chlorophyll-b. The retention time of reverse-phase high-performance liquid chromatography of the synthetic monomeric BChl-f as well as its visible absorption and fluorescence emission spectra in a solution were identified and compared with other naturally occurring chlorophyll pigments obtained from the main light-harvesting antenna systems of green sulfur bacteria, BChls-c/d/e. Based on the above data, BChl-f was below the level of detection in three strains of green photosynthetic bacteria producing BChl-e.
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Affiliation(s)
- Hitoshi Tamiaki
- Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
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14
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Self-aggregates of natural chlorophylls and their synthetic analogues in aqueous media for making light-harvesting systems. Coord Chem Rev 2010. [DOI: 10.1016/j.ccr.2009.12.027] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Shibata Y, Tateishi S, Nakabayashi S, Itoh S, Tamiaki H. Intensity Borrowing via Excitonic Couplings among Soret and Qy Transitions of Bacteriochlorophylls in the Pigment Aggregates of Chlorosomes, the Light-Harvesting Antennae of Green Sulfur Bacteria. Biochemistry 2010; 49:7504-15. [DOI: 10.1021/bi100607c] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yutaka Shibata
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Shingo Tateishi
- Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Shosuke Nakabayashi
- Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Shigeru Itoh
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Hitoshi Tamiaki
- Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
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Linearly polarized light absorption spectra of chlorosomes, light-harvesting antennas of photosynthetic green sulfur bacteria. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2009.12.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Hirai Y, Tamiaki H, Kashimura S, Saga Y. Physicochemical Studies of Demetalation of Light-harvesting Bacteriochlorophyll Isomers Purified from Green Sulfur Photosynthetic Bacteria. Photochem Photobiol 2009; 85:1140-6. [DOI: 10.1111/j.1751-1097.2009.00580.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Saga Y, Harada J, Hattori H, Kaihara K, Hirai Y, Oh-oka H, Tamiaki H. Spectroscopic properties and bacteriochlorophyll c isomer composition of extramembranous light-harvesting complexes in the green sulfur photosynthetic bacterium Chlorobium tepidum and its CT0388-deleted mutant under vitamin B12-limited conditions. Photochem Photobiol Sci 2008; 7:1210-5. [PMID: 18846285 DOI: 10.1039/b802354a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The effects of exogenous vitamin B12 on the green sulfur photosynthetic bacterium Chlorobium (Chl.) tepidum were examined. Wild-type cells and mutant cells lacking a gene CT0388 (denoted as VB0388) of Chl.tepidum were grown in liquid cultures containing different concentrations of vitamin B12. The VB0388 cells hardly grew in vitamin B12-limited media, indicating that the product of CT0388 actually played an important role in vitamin B12 biosynthesis in Chl. tepidum. Both wild-type and VB0388 cells in vitamin B12-limited media exhibited absorption bands and CD signals at the Qy region that were shifted to a shorter wavelength than those of cells grown in normal media. BChl c isomers that had S-stereochemistry at the 3(1)-position tended to increase in Chl. tepidum grown in vitamin B12-limited media.
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Affiliation(s)
- Yoshitaka Saga
- Department of Chemistry, Faculty of Science and Engineering, Kinki University, Higashi-Osaka, Osaka 577-8502, Japan.
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Linnanto JM, Korppi-Tommola JEI. Investigation on chlorosomal antenna geometries: tube, lamella and spiral-type self-aggregates. PHOTOSYNTHESIS RESEARCH 2008; 96:227-245. [PMID: 18443917 DOI: 10.1007/s11120-008-9304-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Accepted: 04/07/2008] [Indexed: 05/26/2023]
Abstract
Molecular mechanics calculations and exciton theory have been used to study pigment organization in chlorosomes of green bacteria. Single and double rod, multiple concentric rod, lamella, and Archimedean spiral macrostructures of bacteriochlorophyll c molecules were created and their spectral properties evaluated. The effects of length, width, diameter, and curvature of the macrostructures as well as orientations of monomeric transition dipole moment vectors on the spectral properties of the aggregates were studied. Calculated absorption, linear dichroism, and polarization dependent fluorescence-excitation spectra of the studied long macrostructures were practically identical, but circular dichroism spectra turned out to be very sensitive to geometry and monomeric transition dipole moment orientations of the aggregates. The simulations for long multiple rod and spiral-type macrostructures, observed in recent high-resolution electron microscopy images (Oostergetel et al., FEBS Lett 581:5435-5439, 2007) gave shapes of circular dichroism spectra observed experimentally for chlorosomes. It was shown that the ratio of total circular dichroism intensity to integrated absorption of the Q(y) transition is a good measure of degree of tubular structures in the chlorosomes. Calculations suggest that the broad Q(y) line width of chlorosomes of sulfur bacteria could be due to (1) different orientations of the transition moment vectors in multi-walled rod structures or (2) a variety of Bchl-aggregate structures in the chlorosomes.
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Affiliation(s)
- Juha M Linnanto
- Department of Chemistry, University of Jyväskylä, Jyväskylä, Finland.
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Saga Y, Hirai Y, Tamiaki H. Kinetic analysis of demetalation of bacteriochlorophyllcandehomologs purified from green sulfur photosynthetic bacteria. FEBS Lett 2007; 581:1847-50. [DOI: 10.1016/j.febslet.2007.03.079] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 03/22/2007] [Accepted: 03/27/2007] [Indexed: 11/25/2022]
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21
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Saga Y, Tamiaki H. Transmission electron microscopic study on supramolecular nanostructures of bacteriochlorophyll self-aggregates in chlorosomes of green photosynthetic bacteria. J Biosci Bioeng 2006; 102:118-23. [PMID: 17027873 DOI: 10.1263/jbb.102.118] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Accepted: 05/27/2006] [Indexed: 11/17/2022]
Abstract
Supramolecular nanostructures of bacteriochlorophyll (BChl) self-aggregates in major light-harvesting complexes (chlorosomes) of green photosynthetic bacteria were successfully observed by freeze-fracture transmission electron microscope. Rod-shaped nanostructures with approximately 10 nm in diameter could be visualized in three types of green sulfur bacteria (Chlorobium). Diameter of the rod-shaped nanostructures in Chlorobium chlorosomes was independent of the molecular structures of their light-harvesting pigments, namely BChl-c or d. In contrast, chlorosomes of the green filamentous bacterium Chloroflexus aurantiacus had rod-shaped nanostructures with approximately 5 nm in diameter. The present results support that BChl self-aggregates in chlorosomes form rod-shaped nanostructures called rod-elements with approximately 10- and 5-nm diameters for Chlorobium and Chloroflexus, respectively.
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Affiliation(s)
- Yoshitaka Saga
- Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
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Saga Y, Akai S, Miyatake T, Tamiaki H. Self-Assembly of Natural Light-Harvesting Bacteriochlorophylls of Green Sulfur Photosynthetic Bacteria in Silicate Capsules as Stable Models of Chlorosomes. Bioconjug Chem 2006; 17:988-94. [PMID: 16848406 DOI: 10.1021/bc050343s] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Naturally occurring bacteriochlorophyll(BChl)s-c, -d, and -e from green sulfur photosynthetic bacteria were self-assembled in an aqueous solution in the presence of octadecyltriethoxysilane and tetraethoxysilane, followed by polycondensation of the alkoxysilanes by incubation for 50 h at 25 degrees C. The resulting BChl self-assemblies in silicate capsules exhibited visible absorption and circular dichroism spectra similar to the corresponding natural light-harvesting systems (chlorosomes) of green sulfur bacteria. Dynamic light scattering measurements indicated that the silicate capsules had an average hydrodynamic diameter of several hundred nanometers. BChl self-aggregates in silicate capsules were significantly stable to a nonionic surfactant Triton X-100, which was apt to decompose the BChl aggregates to their monomeric form, compared with conventional micelle systems. BChls in silicate capsules were more tolerant to demetalation of the central magnesium under acidic conditions than the natural systems.
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Affiliation(s)
- Yoshitaka Saga
- Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
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Harada J, Saga Y, Oh-oka H, Tamiaki H. Different sensitivities to oxygen between two strains of the photosynthetic green sulfur bacterium Chlorobium vibrioforme NCIB 8327 with bacteriochlorophyll c and d. PHOTOSYNTHESIS RESEARCH 2005; 86:137-43. [PMID: 16172933 DOI: 10.1007/s11120-005-5669-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Accepted: 04/18/2005] [Indexed: 05/04/2023]
Abstract
Two sub-strains of the anoxygenic photosynthetic green sulfur bacterium Chlorobium vibrioforme NCIB 8327 were derived from the same clone and could be discriminated only by their possession of either bacteriochlorophyll (BChl) c or d as the major pigment in the peripheral light-harvesting antenna system, chlorosome (Saga Y et al. (2003) Anal Sci 19: 1575-1579). In the presence of a proper amount of oxygen in the initial culture medium, the BChl d strain showed longer retardation on its growth initiation than the BChl c strain, indicating that the latter was advantageous for survival under aerobic light conditions which produced reactive oxygen species in vivo. The result would be ascribable to the difference of the midpoint potentials between two kinds of chlorosomes formed by self-aggregates of BChl c and d as measured by their fluorescence quenching.
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Affiliation(s)
- Jiro Harada
- Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, 525-8577, Shiga, Japan
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Saga Y, Osumi S, Higuchi H, Tamiaki H. Bacteriochlorophyll-c homolog composition in green sulfur photosynthetic bacterium Chlorobium vibrioforme dependent on the concentration of sodium sulfide in liquid cultures. PHOTOSYNTHESIS RESEARCH 2005; 86:123-30. [PMID: 16172931 DOI: 10.1007/s11120-005-5301-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2004] [Accepted: 04/11/2005] [Indexed: 05/04/2023]
Abstract
Green sulfur photosynthetic bacteria Chlorobium (Chl.) vibrioforme (DSM 263 strain and NCIB 8327 substrain possessing BChl-c) and Chl. tepidum (ATCC 49652) were photoautotrophically grown in liquid cultures containing different concentrations of sodium sulfide (Na2S). BChl-c homologs possessing a methyl group at the 12-position tended to increase in cells of the two strains of Chl. vibrioforme cultured under high Na2S concentrations. In contrast, the Na2S concentration in liquid cultures did not affect the relative composition of BChl-c homologs in Chl. tepidum. 8-Propyl-12-methyl([P,M])-BChl-c homolog, which has been little observed in usual cultivations, could be isolated by reverse-phase high-performance liquid chromatography from the cells of Chl. vibrioforme grown under high Na2S contents. The [P,M]-BChl-c homolog has the R-configuration at the 3(1)-position, which was determined by 1H-NMR analyses.
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Affiliation(s)
- Yoshitaka Saga
- Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, 525-8577, Kusatsu, Shiga, Japan
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Harada J, Saga Y, Yaeda Y, Oh-Oka H, Tamiaki H. In vitro activity of C-20 methyltransferase, BchU, involved in bacteriochlorophyllcbiosynthetic pathway in green sulfur bacteria. FEBS Lett 2005; 579:1983-7. [PMID: 15792807 DOI: 10.1016/j.febslet.2005.01.087] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Revised: 02/14/2005] [Accepted: 02/14/2005] [Indexed: 11/21/2022]
Abstract
The activity of a methyltransferase, BchU, which catalyzes methylation at the C-20 position of chlorin ring in the biosynthetic pathway of bacteriochlorophyll c, was investigated in vitro. The bchU gene derived from the photosynthetic green sulfur bacterium, Chlorobium tepidum, was overexpressed in Escherichia coli as a His-tagged protein (His(6)-BchU), and the enzyme was purified. In the presence of S-adenosylmethionine, His(6)-BchU methylated zinc bacteriopheophorbide d at the C-20 position to give zinc bacteriopheophorbide c. Metal-free bacteriopheophorbide d could not be methylated by the BchU, indicating that the central metal in the chlorin should be required for the recognition by the BchU.
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Affiliation(s)
- Jiro Harada
- Department of Bioscience and Biotechnology, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
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