1
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Martin EC, Bowie AGM, Wellfare Reid T, Neil Hunter C, Hitchcock A, Swainsbury DJK. Sulfoquinovosyl diacylglycerol is required for dimerisation of the Rhodobacter sphaeroides reaction centre-light harvesting 1 core complex. Biochem J 2024; 481:823-838. [PMID: 38780411 DOI: 10.1042/bcj20240125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 05/22/2024] [Accepted: 05/23/2024] [Indexed: 05/25/2024]
Abstract
The reaction centre-light harvesting 1 (RC-LH1) core complex is indispensable for anoxygenic photosynthesis. In the purple bacterium Rhodobacter (Rba.) sphaeroides RC-LH1 is produced both as a monomer, in which 14 LH1 subunits form a C-shaped antenna around 1 RC, and as a dimer, where 28 LH1 subunits form an S-shaped antenna surrounding 2 RCs. Alongside the five RC and LH1 subunits, an additional polypeptide known as PufX provides an interface for dimerisation and also prevents LH1 ring closure, introducing a channel for quinone exchange that is essential for photoheterotrophic growth. Structures of Rba. sphaeroides RC-LH1 complexes revealed several new components; protein-Y, which helps to form the quinone channel; protein-Z, of unknown function and seemingly unique to dimers; and a tightly bound sulfoquinovosyl diacylglycerol (SQDG) lipid that interacts with two PufX arginine residues. This lipid lies at the dimer interface alongside weak density for a second molecule, previously proposed to be an ornithine lipid. In this work we have generated strains of Rba. sphaeroides lacking protein-Y, protein-Z, SQDG or ornithine lipids to assess the roles of these previously unknown components in the assembly and activity of RC-LH1. We show that whilst the removal of either protein-Y, protein-Z or ornithine lipids has only subtle effects, SQDG is essential for the formation of RC-LH1 dimers but its absence has no functional effect on the monomeric complex.
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Affiliation(s)
- Elizabeth C Martin
- Plants, Photosynthesis and Soil, School of Bioscience, University of Sheffield, Sheffield, U.K
| | - Adam G M Bowie
- Plants, Photosynthesis and Soil, School of Bioscience, University of Sheffield, Sheffield, U.K
| | - Taylor Wellfare Reid
- Plants, Photosynthesis and Soil, School of Bioscience, University of Sheffield, Sheffield, U.K
| | - C Neil Hunter
- Plants, Photosynthesis and Soil, School of Bioscience, University of Sheffield, Sheffield, U.K
| | - Andrew Hitchcock
- Plants, Photosynthesis and Soil, School of Bioscience, University of Sheffield, Sheffield, U.K
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2
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Xin J, Shi Y, Zhang X, Yuan X, Xin Y, He H, Shen J, Blankenship RE, Xu X. Carotenoid assembly regulates quinone diffusion and the Roseiflexus castenholzii reaction center-light harvesting complex architecture. eLife 2023; 12:e88951. [PMID: 37737710 PMCID: PMC10516601 DOI: 10.7554/elife.88951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/16/2023] [Indexed: 09/23/2023] Open
Abstract
Carotenoid (Car) pigments perform central roles in photosynthesis-related light harvesting (LH), photoprotection, and assembly of functional pigment-protein complexes. However, the relationships between Car depletion in the LH, assembly of the prokaryotic reaction center (RC)-LH complex, and quinone exchange are not fully understood. Here, we analyzed native RC-LH (nRC-LH) and Car-depleted RC-LH (dRC-LH) complexes in Roseiflexus castenholzii, a chlorosome-less filamentous anoxygenic phototroph that forms the deepest branch of photosynthetic bacteria. Newly identified exterior Cars functioned with the bacteriochlorophyll B800 to block the proposed quinone channel between LHαβ subunits in the nRC-LH, forming a sealed LH ring that was disrupted by transmembrane helices from cytochrome c and subunit X to allow quinone shuttling. dRC-LH lacked subunit X, leading to an exposed LH ring with a larger opening, which together accelerated the quinone exchange rate. We also assigned amino acid sequences of subunit X and two hypothetical proteins Y and Z that functioned in forming the quinone channel and stabilizing the RC-LH interactions. This study reveals the structural basis by which Cars assembly regulates the architecture and quinone exchange of bacterial RC-LH complexes. These findings mark an important step forward in understanding the evolution and diversity of prokaryotic photosynthetic apparatus.
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Affiliation(s)
- Jiyu Xin
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences and The Affiliated Hospital of Hangzhou Normal UniversityHangzhouChina
| | - Yang Shi
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence & Department of Neurobiology and Department of Pathology of the First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang UniversityHangzhouChina
| | - Xin Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences and The Affiliated Hospital of Hangzhou Normal UniversityHangzhouChina
- Photosynthesis Research Center, College of Life and Environmental Sciences, Hangzhou Normal UniversityHangzhouChina
| | - Xinyi Yuan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences and The Affiliated Hospital of Hangzhou Normal UniversityHangzhouChina
- Photosynthesis Research Center, College of Life and Environmental Sciences, Hangzhou Normal UniversityHangzhouChina
| | - Yueyong Xin
- Photosynthesis Research Center, College of Life and Environmental Sciences, Hangzhou Normal UniversityHangzhouChina
| | - Huimin He
- Photosynthesis Research Center, College of Life and Environmental Sciences, Hangzhou Normal UniversityHangzhouChina
| | - Jiejie Shen
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences and The Affiliated Hospital of Hangzhou Normal UniversityHangzhouChina
| | - Robert E Blankenship
- Departments of Biology and Chemistry, Washington University in St. LouisSt. LouisUnited States
| | - Xiaoling Xu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences and The Affiliated Hospital of Hangzhou Normal UniversityHangzhouChina
- Photosynthesis Research Center, College of Life and Environmental Sciences, Hangzhou Normal UniversityHangzhouChina
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3
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Thwaites O, Christianson BM, Cowan AJ, Jäckel F, Liu LN, Gardner AM. Unravelling the Roles of Integral Polypeptides in Excitation Energy Transfer of Photosynthetic RC-LH1 Supercomplexes. J Phys Chem B 2023; 127:7283-7290. [PMID: 37556839 PMCID: PMC10461223 DOI: 10.1021/acs.jpcb.3c04466] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 07/24/2023] [Indexed: 08/11/2023]
Abstract
Elucidating the photosynthetic processes that occur within the reaction center-light-harvesting 1 (RC-LH1) supercomplexes from purple bacteria is crucial for uncovering the assembly and functional mechanisms of natural photosynthetic systems and underpinning the development of artificial photosynthesis. Here, we examined excitation energy transfer of various RC-LH1 supercomplexes of Rhodobacter sphaeroides using transient absorption spectroscopy, coupled with lifetime density analysis, and studied the roles of the integral transmembrane polypeptides, PufX and PufY, in energy transfer within the RC-LH1 core complex. Our results show that the absence of PufX increases both the LH1 → RC excitation energy transfer lifetime and distribution due to the role of PufX in defining the interaction and orientation of the RC within the LH1 ring. While the absence of PufY leads to the conformational shift of several LH1 subunits toward the RC, it does not result in a marked change in the excitation energy transfer lifetime.
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Affiliation(s)
- Owen Thwaites
- Stephenson
Institute of Renewable Energy, University
of Liverpool, Liverpool L69 7ZF, U.K.
- Department
of Physics, University of Liverpool, Liverpool L69 7ZE, U.K.
| | - Bern M. Christianson
- Institute
of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, U.K.
| | - Alexander J. Cowan
- Stephenson
Institute of Renewable Energy, University
of Liverpool, Liverpool L69 7ZF, U.K.
- Department
of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K.
| | - Frank Jäckel
- Stephenson
Institute of Renewable Energy, University
of Liverpool, Liverpool L69 7ZF, U.K.
- Department
of Physics, University of Liverpool, Liverpool L69 7ZE, U.K.
| | - Lu-Ning Liu
- Institute
of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, U.K.
- College
of Marine Life Sciences, and Frontiers Science Center for Deep Ocean
Multispheres and Earth System, Ocean University
of China, Qingdao 266003, China
| | - Adrian M. Gardner
- Stephenson
Institute of Renewable Energy, University
of Liverpool, Liverpool L69 7ZF, U.K.
- Department
of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K.
- Early Career
Laser Laboratory, University of Liverpool, Liverpool L69 3BX, U.K.
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4
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Trindade IB, Firmino MO, Noordam SJ, Alves AS, Fonseca BM, Piccioli M, Louro RO. Protein Interactions in Rhodopseudomonas palustris TIE-1 Reveal the Molecular Basis for Resilient Photoferrotrophic Iron Oxidation. Molecules 2023; 28:4733. [PMID: 37375288 DOI: 10.3390/molecules28124733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 06/06/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
Rhodopseudomonas palustris is an alphaproteobacterium with impressive metabolic versatility, capable of oxidizing ferrous iron to fix carbon dioxide using light energy. Photoferrotrophic iron oxidation is one of the most ancient metabolisms, sustained by the pio operon coding for three proteins: PioB and PioA, which form an outer-membrane porin-cytochrome complex that oxidizes iron outside of the cell and transfers the electrons to the periplasmic high potential iron-sulfur protein (HIPIP) PioC, which delivers them to the light-harvesting reaction center (LH-RC). Previous studies have shown that PioA deletion is the most detrimental for iron oxidation, while, the deletion of PioC resulted in only a partial loss. The expression of another periplasmic HiPIP, designated Rpal_4085, is strongly upregulated in photoferrotrophic conditions, making it a strong candidate for a PioC substitute. However, it is unable to reduce the LH-RC. In this work we used NMR spectroscopy to map the interactions between PioC, PioA, and the LH-RC, identifying the key amino acid residues involved. We also observed that PioA directly reduces the LH-RC, and this is the most likely substitute upon PioC deletion. By contrast, Rpal_4085 demontrated significant electronic and structural differences from PioC. These differences likely explain its inability to reduce the LH-RC and highlight its distinct functional role. Overall, this work reveals the functional resilience of the pio operon pathway and further highlights the use of paramagnetic NMR for understanding key biological processes.
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Affiliation(s)
- Inês B Trindade
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157 Oeiras, Portugal
| | - Maria O Firmino
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157 Oeiras, Portugal
| | - Sander J Noordam
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157 Oeiras, Portugal
| | - Alexandra S Alves
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157 Oeiras, Portugal
| | - Bruno M Fonseca
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157 Oeiras, Portugal
| | - Mario Piccioli
- Magnetic Resonance Center, Department of Chemistry, University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy
| | - Ricardo O Louro
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157 Oeiras, Portugal
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5
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The role of the γ subunit in the photosystem of the lowest-energy phototrophs. Biochem J 2022; 479:2449-2463. [PMID: 36534468 PMCID: PMC9788563 DOI: 10.1042/bcj20220508] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/25/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022]
Abstract
Purple phototrophic bacteria use a 'photosystem' consisting of light harvesting complex 1 (LH1) surrounding the reaction centre (RC) that absorbs far-red-near-infrared light and converts it to chemical energy. Blastochloris species, which harvest light >1000 nm, use bacteriochlorophyll b rather than the more common bacteriochlorophyll a as their major photopigment, and assemble LH1 with an additional polypeptide subunit, LH1γ, encoded by multiple genes. To assign a role to γ, we deleted the four encoding genes in the model Blastochloris viridis. Interestingly, growth under halogen bulbs routinely used for cultivation yielded cells displaying an absorption maximum of 825 nm, similar to that of the RC only, but growth under white light yielded cells with an absorption maximum at 972 nm. HPLC analysis of pigment composition and sucrose gradient fractionation demonstrate that the white light-grown mutant assembles RC-LH1, albeit with an absorption maximum blue-shifted by 46 nm. Wavelengths between 900-1000 nm transmit poorly through the atmosphere due to absorption by water, so our results provide an evolutionary rationale for incorporation of γ; this polypeptide red-shifts absorption of RC-LH1 to a spectral range in which photons are of lower energy but are more abundant. Finally, we transformed the mutant with plasmids encoding natural LH1γ variants and demonstrate that the polypeptide found in the wild type complex red-shifts absorption back to 1018 nm, but incorporation of a distantly related variant results in only a moderate shift. This result suggests that tuning the absorption of RC-LH1 is possible and may permit photosynthesis past its current low-energy limit.
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6
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Brown B, Wilkins M, Saha R. Rhodopseudomonas palustris: A biotechnology chassis. Biotechnol Adv 2022; 60:108001. [PMID: 35680002 DOI: 10.1016/j.biotechadv.2022.108001] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 05/18/2022] [Accepted: 06/01/2022] [Indexed: 11/26/2022]
Abstract
Rhodopseudomonas palustris is an attractive option for biotechnical applications and industrial engineering due to its metabolic versatility and its ability to catabolize a wide variety of feedstocks and convert them to several high-value products. Given its adaptable metabolism, R. palustris has been studied and applied in an extensive variety of applications such as examining metabolic tradeoffs for environmental perturbations, biodegradation of aromatic compounds, environmental remediation, biofuel production, agricultural biostimulation, and bioelectricity production. This review provides a holistic summary of the commercial applications for R. palustris as a biotechnology chassis and suggests future perspectives for research and engineering.
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Affiliation(s)
- Brandi Brown
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
| | - Mark Wilkins
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; Industrial Agricultural Products Center, University of Nebraska-Lincoln, Lincoln, NE 68583, USA; Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Rajib Saha
- Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.
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7
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Structural basis for the assembly and quinone transport mechanisms of the dimeric photosynthetic RC-LH1 supercomplex. Nat Commun 2022; 13:1977. [PMID: 35418573 PMCID: PMC9007983 DOI: 10.1038/s41467-022-29563-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 03/22/2022] [Indexed: 12/15/2022] Open
Abstract
The reaction center (RC) and light-harvesting complex 1 (LH1) form a RC-LH1 core supercomplex that is vital for the primary reactions of photosynthesis in purple phototrophic bacteria. Some species possess the dimeric RC-LH1 complex with a transmembrane polypeptide PufX, representing the largest photosynthetic complex in anoxygenic phototrophs. However, the details of the architecture and assembly mechanism of the RC-LH1 dimer are unclear. Here we report seven cryo-electron microscopy (cryo-EM) structures of RC-LH1 supercomplexes from Rhodobacter sphaeroides. Our structures reveal that two PufX polypeptides are positioned in the center of the S-shaped RC-LH1 dimer, interlocking association between the components and mediating RC-LH1 dimerization. Moreover, we identify another transmembrane peptide, designated PufY, which is located between the RC and LH1 subunits near the LH1 opening. PufY binds a quinone molecule and prevents LH1 subunits from completely encircling the RC, creating a channel for quinone/quinol exchange. Genetic mutagenesis, cryo-EM structures, and computational simulations provide a mechanistic understanding of the assembly and electron transport pathways of the RC-LH1 dimer and elucidate the roles of individual components in ensuring the structural and functional integrity of the photosynthetic supercomplex.
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8
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Sutherland GA, Qian P, Hunter CN, Swainsbury DJ, Hitchcock A. Engineering purple bacterial carotenoid biosynthesis to study the roles of carotenoids in light-harvesting complexes. Methods Enzymol 2022; 674:137-184. [DOI: 10.1016/bs.mie.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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9
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du Toit JP, Lea-Smith DJ, Git A, Hervey JRD, Howe CJ, Pott RWM. Expression of Alternative Nitrogenases in Rhodopseudomonas palustris Is Enhanced Using an Optimized Genetic Toolset for Rapid, Markerless Modifications. ACS Synth Biol 2021; 10:2167-2178. [PMID: 34431288 DOI: 10.1021/acssynbio.0c00496] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The phototrophic bacterium Rhodopseudomonas palustris is emerging as a promising biotechnological chassis organism, due to its resilience to a range of harsh conditions, a wide metabolic repertoire, and the ability to quickly regenerate ATP using light. However, realization of this promise is impeded by a lack of efficient, rapid methods for genetic modification. Here, we present optimized tools for generating chromosomal insertions and deletions employing electroporation as a means of transformation. Generation of markerless strains can be completed in 12 days, approximately half the time for previous conjugation-based methods. This system was used for overexpression of alternative nitrogenase isozymes with the aim of improving biohydrogen productivity. Insertion of the pucBa promoter upstream of vnf and anf nitrogenase operons drove robust overexpression up to 4000-fold higher than wild-type. Transcript quantification was facilitated by an optimized high-quality RNA extraction protocol employing lysis using detergent and heat. Overexpression resulted in increased nitrogenase protein levels, extending to superior hydrogen productivity in bioreactor studies under nongrowing conditions, where promoter-modified strains better utilized the favorable energy state created by reduced competition from cell division. Robust heterologous expression driven by the pucBa promoter is thus attractive for energy-intensive biosyntheses suited to the capabilities of R. palustris. Development of this genetic modification toolset will accelerate the advancement of R. palustris as a biotechnological chassis organism, and insights into the effects of nitrogenase overexpression will guide future efforts in engineering strains for improved hydrogen production.
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Affiliation(s)
- Jan-Pierre du Toit
- Department of Process Engineering, Stellenbosch University, Banghoek Road, Stellenbosch, 7600, South Africa
| | - David J. Lea-Smith
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom
- Department of Biochemistry, University of Cambridge, Hopkins Building, Downing Site, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
| | - Anna Git
- Department of Biochemistry, University of Cambridge, Hopkins Building, Downing Site, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
| | - John R. D. Hervey
- Department of Biochemistry, University of Cambridge, Hopkins Building, Downing Site, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
| | - Christopher J. Howe
- Department of Biochemistry, University of Cambridge, Hopkins Building, Downing Site, Tennis Court Road, Cambridge, CB2 1QW, United Kingdom
| | - Robert W. M. Pott
- Department of Process Engineering, Stellenbosch University, Banghoek Road, Stellenbosch, 7600, South Africa
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10
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Swainsbury DJK, Qian P, Jackson PJ, Faries KM, Niedzwiedzki DM, Martin EC, Farmer DA, Malone LA, Thompson RF, Ranson NA, Canniffe DP, Dickman MJ, Holten D, Kirmaier C, Hitchcock A, Hunter CN. Structures of Rhodopseudomonas palustris RC-LH1 complexes with open or closed quinone channels. SCIENCE ADVANCES 2021; 7:7/3/eabe2631. [PMID: 33523887 PMCID: PMC7806223 DOI: 10.1126/sciadv.abe2631] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/18/2020] [Indexed: 05/23/2023]
Abstract
The reaction-center light-harvesting complex 1 (RC-LH1) is the core photosynthetic component in purple phototrophic bacteria. We present two cryo-electron microscopy structures of RC-LH1 complexes from Rhodopseudomonas palustris A 2.65-Å resolution structure of the RC-LH114-W complex consists of an open 14-subunit LH1 ring surrounding the RC interrupted by protein-W, whereas the complex without protein-W at 2.80-Å resolution comprises an RC completely encircled by a closed, 16-subunit LH1 ring. Comparison of these structures provides insights into quinone dynamics within RC-LH1 complexes, including a previously unidentified conformational change upon quinone binding at the RC QB site, and the locations of accessory quinone binding sites that aid their delivery to the RC. The structurally unique protein-W prevents LH1 ring closure, creating a channel for accelerated quinone/quinol exchange.
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Affiliation(s)
- David J K Swainsbury
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
| | - Pu Qian
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands
| | - Philip J Jackson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, S1 3JD, UK
| | - Kaitlyn M Faries
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Dariusz M Niedzwiedzki
- Center for Solar Energy and Energy Storage, Washington University in St. Louis, St. Louis, MO 63130, USA
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Elizabeth C Martin
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - David A Farmer
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Lorna A Malone
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Rebecca F Thompson
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Neil A Ranson
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Daniel P Canniffe
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Mark J Dickman
- Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, S1 3JD, UK
| | - Dewey Holten
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Christine Kirmaier
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Andrew Hitchcock
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK.
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11
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Gardiner AT, Nguyen-Phan TC, Cogdell RJ. A comparative look at structural variation among RC-LH1 'Core' complexes present in anoxygenic phototrophic bacteria. PHOTOSYNTHESIS RESEARCH 2020; 145:83-96. [PMID: 32430765 PMCID: PMC7423801 DOI: 10.1007/s11120-020-00758-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/10/2020] [Indexed: 05/30/2023]
Abstract
All purple photosynthetic bacteria contain RC-LH1 'Core' complexes. The structure of this complex from Rhodobacter sphaeroides, Rhodopseudomonas palustris and Thermochromatium tepidum has been solved using X-ray crystallography. Recently, the application of single particle cryo-EM has revolutionised structural biology and the structure of the RC-LH1 'Core' complex from Blastochloris viridis has been solved using this technique, as well as the complex from the non-purple Chloroflexi species, Roseiflexus castenholzii. It is apparent that these structures are variations on a theme, although with a greater degree of structural diversity within them than previously thought. Furthermore, it has recently been discovered that the only phototrophic representative from the phylum Gemmatimonadetes, Gemmatimonas phototrophica, also contains a RC-LH1 'Core' complex. At present only a low-resolution EM-projection map exists but this shows that the Gemmatimonas phototrophica complex contains a double LH1 ring. This short review compares these different structures and looks at the functional significance of these variations from two main standpoints: energy transfer and quinone exchange.
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Affiliation(s)
- Alastair T Gardiner
- Institute of Molecular, Cellular and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
- Laboratory of Anoxygenic Phototrophs, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Novohradska 237, 379 01, Třeboň, Czech Republic.
| | - Tu C Nguyen-Phan
- Institute of Molecular, Cellular and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Richard J Cogdell
- Institute of Molecular, Cellular and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
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12
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Lai EP, Kersten H, Benter T. Ion-Trap Mass Spectrometric Analysis of Bisphenol A Interactions With Titanium Dioxide Nanoparticles and Milk Proteins. Molecules 2020; 25:E708. [PMID: 32041367 PMCID: PMC7037553 DOI: 10.3390/molecules25030708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 01/27/2020] [Accepted: 02/05/2020] [Indexed: 11/21/2022] Open
Abstract
Quantitative analysis of endocrine-disrupting molecules such as bisphenol A (BPA) in freshwater to determine their widespread occurrence in environmental resources has been challenged by various adsorption and desorption processes. In this work, ion trap mass spectrometry (ITMS) analysis of BPA was aimed at studying its molecular interactions with titanium dioxide (TiO2) nanoparticles and milk whey proteins. Addition of sodium formate prevented TiO2 nanoparticles from sedimentation while enhancing the electrospray ionization (ESI) efficiency to produce an abundance of [BPA + Na]+ ions at m/z 251.0. More importantly, the ESI-ITMS instrument could operate properly during a direct infusion of nanoparticles up to 500 μg/mL without clogging the intake capillary. Milk protein adsorption of BPA could decrease the [BPA + Na]+ peak intensity significantly unless the proteins were partially removed by curdling to produce whey, which allowed BPA desorption during ESI for quantitative analysis by ITMS.
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Affiliation(s)
- Edward P.C. Lai
- Ottawa-Carleton Chemistry Institute, Department of Chemistry, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Hendrik Kersten
- Institute for Pure and Applied Mass Spectrometry, Physical and Theoretical Chemistry, Bergische Universität Wuppertal, Gaussstr. 20, 42119 Wuppertal, Germany; (H.K.); (T.B.)
| | - Thorsten Benter
- Institute for Pure and Applied Mass Spectrometry, Physical and Theoretical Chemistry, Bergische Universität Wuppertal, Gaussstr. 20, 42119 Wuppertal, Germany; (H.K.); (T.B.)
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Imanishi M, Takenouchi M, Takaichi S, Nakagawa S, Saga Y, Takenaka S, Madigan MT, Overmann J, Wang-Otomo ZY, Kimura Y. A Dual Role for Ca 2+ in Expanding the Spectral Diversity and Stability of Light-Harvesting 1 Reaction Center Photocomplexes of Purple Phototrophic Bacteria. Biochemistry 2019; 58:2844-2852. [PMID: 31145583 DOI: 10.1021/acs.biochem.9b00351] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The light-harvesting 1 reaction center (LH1-RC) complex in the purple sulfur bacterium Thiorhodovibrio ( Trv.) strain 970 cells exhibits its LH1 Q y transition at 973 nm, the lowest-energy Q y absorption among purple bacteria containing bacteriochlorophyll a (BChl a). Here we characterize the origin of this extremely red-shifted Q y transition. Growth of Trv. strain 970 did not occur in cultures free of Ca2+, and elemental analysis of Ca2+-grown cells confirmed that purified Trv. strain 970 LH1-RC complexes contained Ca2+. The LH1 Q y band of Trv. strain 970 was blue-shifted from 959 to 875 nm upon Ca2+ depletion, but the original spectral properties were restored upon Ca2+ reconstitution, which also occurs with the thermophilic purple bacterium Thermochromatium ( Tch.) tepidum. The amino acid sequences of the LH1 α- and β-polypeptides from Trv. strain 970 closely resemble those of Tch. tepidum; however, Ca2+ binding in the Trv. strain 970 LH1-RC occurred more selectively than in Tch. tepidum LH1-RC and with a reduced affinity. Ultraviolet resonance Raman analysis indicated that the number of hydrogen-bonding interactions between BChl a and LH1 proteins of Trv. strain 970 was significantly greater than for Tch. tepidum and that Ca2+ was indispensable for maintaining these bonds. Furthermore, perfusion-induced Fourier transform infrared analyses detected Ca2+-induced conformational changes in the binding site closely related to the unique spectral properties of Trv. strain 970. Collectively, our results reveal an ecological strategy employed by Trv. strain 970 of integrating Ca2+ into its LH1-RC complex to extend its light-harvesting capacity to regions of the near-infrared spectrum unused by other purple bacteria.
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Affiliation(s)
- Michie Imanishi
- Graduate School of Agricultural Science , Kobe University , Nada, Kobe 657-8501 , Japan
| | - Mizuki Takenouchi
- Faculty of Science , Ibaraki University , Bunkyo, Mito 310-8512 , Japan
| | - Shinichi Takaichi
- Faculty of Life Sciences , Tokyo University of Agriculture , Setagaya, Tokyo 156-8502 , Japan
| | - Shiori Nakagawa
- Department of Chemistry , Kindai University , Higashi-Osaka, Osaka 577-8502 , Japan
| | - Yoshitaka Saga
- Department of Chemistry , Kindai University , Higashi-Osaka, Osaka 577-8502 , Japan
| | - Shinji Takenaka
- Graduate School of Agricultural Science , Kobe University , Nada, Kobe 657-8501 , Japan
| | - Michael T Madigan
- Department of Microbiology , Southern Illinois University , Carbondale , Illinois 62901 , United States
| | - Jörg Overmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures , 38124 Braunschweig , Germany.,Microbiology , Braunschweig University of Technology , 38106 Braunschweig , Germany
| | | | - Yukihiro Kimura
- Graduate School of Agricultural Science , Kobe University , Nada, Kobe 657-8501 , Japan
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