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Azai C, Sano Y, Kato Y, Noguchi T, Oh-oka H. Mutation-induced perturbation of the special pair P840 in the homodimeric reaction center in green sulfur bacteria. Sci Rep 2016; 6:19878. [PMID: 26804137 PMCID: PMC4726426 DOI: 10.1038/srep19878] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 12/18/2015] [Indexed: 11/11/2022] Open
Abstract
Homodimeric photosynthetic reaction centers (RCs) in green sulfur bacteria and heliobacteria are functional homologs of Photosystem (PS) I in oxygenic phototrophs. They show unique features in their electron transfer reactions; however, detailed structural information has not been available so far. We mutated PscA-Leu688 and PscA-Val689 to cysteine residues in the green sulfur bacterium Chlorobaculum tepidum; these residues were predicted to interact with the special pair P840, based on sequence comparison with PS I. Spectroelectrochemical measurements showed that the L688C and V689C mutations altered a near-infrared difference spectrum upon P840 oxidation, as well as the redox potential of P840. Light-induced Fourier transform infrared difference measurements showed that the L688C mutation induced a differential signal of the S-H stretching vibration in the P840+/P840 spectrum, as reported in P800+/P800 difference spectrum in a heliobacterial RC. Spectral changes in the 131-keto C=O region, caused by both mutations, revealed corresponding changes in the electronic structure of P840 and in the hydrogen-bonding interaction at the 131-keto C=O group. These results suggest that there is a common spatial configuration around the special pair sites among type 1 RCs. The data also provided evidence that P840 has a symmetric electronic structure, as expected from a homodimeric RC.
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Affiliation(s)
- Chihiro Azai
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Yuko Sano
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Yuki Kato
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Takumi Noguchi
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Hirozo Oh-oka
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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Zabelin AA, Shkuropatova VA, Shkuropatov AY, Shuvalov VA. Temperature dependence of light-induced absorbance changes associated with chlorophyll photooxidation in manganese-depleted core complexes of photosystem II. BIOCHEMISTRY (MOSCOW) 2015; 80:1279-87. [DOI: 10.1134/s0006297915100089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Noguchi T. Fourier transform infrared spectroscopy of special pair bacteriochlorophylls in homodimeric reaction centers of heliobacteria and green sulfur bacteria. PHOTOSYNTHESIS RESEARCH 2010; 104:321-331. [PMID: 20094792 DOI: 10.1007/s11120-009-9509-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Accepted: 11/25/2009] [Indexed: 05/28/2023]
Abstract
Heliobacteria and green sulfur bacteria have type I homodimeric reaction centers analogous to photosystem I. One remaining question regarding these homodimeric reaction centers is whether the structures and electron transfer reactions are truly symmetric or not. This question is relevant to the origin of the heterodimeric reaction centers, such as photosystem I and type II reaction centers. In this mini-review, Fourier transform infrared studies on the special pair bacteriochlorophylls, P798 in heliobacteria and P840 in green sulfur bacteria, are summarized. The data are reinterpreted in the light of the X-ray crystallographic structure of photosystem I and the sequence alignments of type I reaction center proteins, and discussed in terms of hydrogen bonding interactions and the symmetry of charge distribution over the dimer.
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Affiliation(s)
- Takumi Noguchi
- Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki, Japan.
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Roy E, Gast P, van Gorkom H, de Groot HJM, Jeschke G, Matysik J. Photochemically induced dynamic nuclear polarization in the reaction center of the green sulphur bacterium Chlorobium tepidum observed by 13C MAS NMR. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:610-5. [PMID: 17292850 DOI: 10.1016/j.bbabio.2006.12.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Revised: 12/21/2006] [Accepted: 12/29/2006] [Indexed: 11/30/2022]
Abstract
Photochemically induced dynamic nuclear polarization has been observed in reaction centres of the green sulphur bacterium Chlorobium tepidum by (13)C magic-angle spinning solid-state NMR under continuous illumination with white light. An almost complete set of chemical shifts of the aromatic ring carbons of a BChl a molecule has been obtained. All light-induced (13)C NMR signals appear to be emissive, which is similar to the pattern observed in the reaction centers of plant photosystem I and purple bacterial reaction centres of Rhodobacter sphaeroides wild type. The donor in RCs of green sulfur bacteria clearly differs from the substantially asymmetric special pair of purple bacteria and appears to be similar to the more symmetric donor of photosystem I.
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Affiliation(s)
- Esha Roy
- Leiden Institute of Chemistry, Gorlaeus Laboratoria, 2300 RA Leiden, The Netherlands
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Sivakumar V, Wang R, Hastings G. Photo-oxidation of P740, the primary electron donor in photosystem I from Acaryochloris marina. Biophys J 2004; 85:3162-72. [PMID: 14581216 PMCID: PMC1303592 DOI: 10.1016/s0006-3495(03)74734-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Fourier transform infrared spectroscopy (FTIR) difference spectroscopy in combination with deuterium exchange experiments has been used to study the photo-oxidation of P740, the primary electron donor in photosystem I from Acaryochloris marina. Comparison of (P740(+)-P740) and (P700(+)-P700) FTIR difference spectra show that P700 and P740 share many structural similarities. However, there are several distinct differences also: 1), The (P740(+)-P740) FTIR difference spectrum is significantly altered upon proton exchange, considerably more so than the (P700(+)-P700) FTIR difference spectrum. The P740 binding pocket is therefore more accessible than the P700 binding pocket. 2), Broad, "dimer" absorption bands are observed for both P700(+) and P740(+). These bands differ significantly in substructure, however, suggesting differences in the electronic organization of P700(+) and P740(+). 3), Bands are observed at 2727(-) and 2715(-) cm(-1) in the (P740(+)-P740) FTIR difference spectrum, but are absent in the (P700(+)-P700) FTIR difference spectrum. These bands are due to formyl CH modes of chlorophyll d. Therefore, P740 consists of two chlorophyll d molecules. Deuterium-induced modification of the (P740(+)-P740) FTIR difference spectrum indicates that only the highest frequency 13(3) ester carbonyl mode of P740 downshifts, indicating that this ester mode is weakly H-bonded. In contrast, the highest frequency ester carbonyl mode of P700 is free from H-bonding. Deuterium-induced changes in (P740(+)-P740) FTIR difference spectrum could also indicate that one of the chlorophyll d 3(1) carbonyls of P740 is hydrogen bonded.
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Affiliation(s)
- Velautham Sivakumar
- Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303, USA
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Reimers JR, Shapley WA, Hush NS. Modelling the bacterial photosynthetic reaction center. V. Assignment of the electronic transition observed at 2200 cm−1in the special-pair radical-cation as a second-highest occupied molecular orbital to highest occupied molecular orbital transition. J Chem Phys 2003. [DOI: 10.1063/1.1569909] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Hauska G, Schoedl T, Remigy H, Tsiotis G. The reaction center of green sulfur bacteria(1). BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1507:260-77. [PMID: 11687219 DOI: 10.1016/s0005-2728(01)00200-6] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The composition of the P840-reaction center complex (RC), energy and electron transfer within the RC, as well as its topographical organization and interaction with other components in the membrane of green sulfur bacteria are presented, and compared to the FeS-type reaction centers of Photosystem I and of Heliobacteria. The core of the RC is homodimeric, since pscA is the only gene found in the genome of Chlorobium tepidum which resembles the genes psaA and -B for the heterodimeric core of Photosystem I. Functionally intact RC can be isolated from several species of green sulfur bacteria. It is generally composed of five subunits, PscA-D plus the BChl a-protein FMO. Functional cores, with PscA and PscB only, can be isolated from Prostecochloris aestuarii. The PscA-dimer binds P840, a special pair of BChl a-molecules, the primary electron acceptor A(0), which is a Chl a-derivative and FeS-center F(X). An equivalent to the electron acceptor A(1) in Photosystem I, which is tightly bound phylloquinone acting between A(0) and F(X), is not required for forward electron transfer in the RC of green sulfur bacteria. This difference is reflected by different rates of electron transfer between A(0) and F(X) in the two systems. The subunit PscB contains the two FeS-centers F(A) and F(B). STEM particle analysis suggests that the core of the RC with PscA and PscB resembles the PsaAB/PsaC-core of the P700-reaction center in Photosystem I. PscB may form a protrusion into the cytoplasmic space where reduction of ferredoxin occurs, with FMO trimers bound on both sides of this protrusion. Thus the subunit composition of the RC in vivo should be 2(FMO)(3)(PscA)(2)PscB(PscC)(2)PscD. Only 16 BChl a-, four Chl a-molecules and two carotenoids are bound to the RC-core, which is substantially less than its counterpart of Photosystem I, with 85 Chl a-molecules and 22 carotenoids. A total of 58 BChl a/RC are present in the membranes of green sulfur bacteria outside the chlorosomes, corresponding to two trimers of FMO (42 Bchl a) per RC (16 BChl a). The question whether the homodimeric RC is totally symmetric is still open. Furthermore, it is still unclear which cytochrome c is the physiological electron donor to P840(+). Also the way of NAD(+)-reduction is unknown, since a gene equivalent to ferredoxin-NADP(+) reductase is not present in the genome.
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Affiliation(s)
- G Hauska
- Lehstuhl für Zellbiologie und Pflanzenphysiologie, Universität Regensburg, Germany.
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Rigby SE, Evans MC, Heathcote P. Electron nuclear double resonance (ENDOR) spectroscopy of radicals in photosystem I and related Type 1 photosynthetic reaction centres. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1507:247-59. [PMID: 11687218 DOI: 10.1016/s0005-2728(01)00211-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- S E Rigby
- School of Biological Sciences, University of London, UK.
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Breton J. Fourier transform infrared spectroscopy of primary electron donors in type I photosynthetic reaction centers. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1507:180-93. [PMID: 11687214 DOI: 10.1016/s0005-2728(01)00206-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The vibrational properties of the primary electron donors (P) of type I photosynthetic reaction centers, as investigated by Fourier transform infrared (FTIR) difference spectroscopy in the last 15 years, are briefly reviewed. The results obtained on the microenvironment of the chlorophyll molecules in P700 of photosystem I and of the bacteriochlorophyll molecules in P840 of the green bacteria (Chlorobium) and in P798 of heliobacteria are presented and discussed with special attention to the bonding interactions with the protein of the carbonyl groups and of the central Mg atom of the pigments. The observation of broad electronic transitions in the mid-IR for the cationic state of all the primary donors investigated provides evidence for charge repartition over two (B)Chl molecules. In the green sulfur bacteria and the heliobacteria, the assignments proposed for the carbonyl groups of P and P(+) are still very tentative. In contrast, the axial ligands of P700 in photosystem I have been identified and the vibrational properties of the chlorophyll (Chl) molecules involved in P700, P700(+), and (3)P700 are well described in terms of two molecules, denoted P(1) and P(2), with very different hydrogen bonding patterns. While P(1) has hydrogen bonds to both the 9-keto and the 10a-ester C=O groups and bears all the triplet character in (3)P700, the carbonyl groups of P(2) are free from hydrogen bonding. The positive charge in P700(+) is shared between the two Chl molecules with a ratio ranging from 1:1 to 2:1, in favor of P(2), depending on the temperature and the species. The localization of the triplet in (3)P700 and of the unpaired electron in P700(+) deduced from FTIR spectroscopy is in sharp contrast with that resulting from the analysis of the magnetic resonance experiments. However, the FTIR results are in excellent agreement with the most recent structural model derived from X-ray crystallography of photosystem I at 2.5 A resolution that reveals the hydrogen bonds to the carbonyl groups of the Chl in P700 as well as the histidine ligands of the central Mg atoms predicted from the FTIR data.
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Affiliation(s)
- J Breton
- SBE/DBCM, CEA-Saclay, 91191 Cedex, Gif-sur-Yvette, France.
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van der Est A, Hager-Braun C, Leibl W, Hauska G, Stehlik D. Transient electron paramagnetic resonance spectroscopy on green-sulfur bacteria and heliobacteria at two microwave frequencies. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1409:87-98. [PMID: 9838060 DOI: 10.1016/s0005-2728(98)00152-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Spin polarized transient EPR spectra taken at X-band (9 GHz) and K-band (24 GHz) of membrane fragments of Chlorobium tepidum and Heliobacillus mobilis are presented along with the spectra of two fractions obtained in the purification of reaction centers (RC) from C. tepidum. The lifetime of P+. is determined by measuring the decay of the EPR signals following relaxation of the initial spin polarization. All samples except one of the RC fractions show evidence of light induced charge separation and formation of chlorophyll triplet states. The lifetime of P+. is found to be biexponential with components of 1.5 ms and 30 ms for C. tepidum and 1.0 and 4.5 ms for Hc. mobilis at 100 K. In both cases, the rates are assigned to recombination from F-X. The spin polarized radical pair spectra for both species are similar and those from Hc. mobilis at room temperature and 100 K are identical. In all cases, an emission/absorption polarization pattern with a net absorption is observed. A slight narrowing of the spectra and a larger absorptive net polarization is found at K-band. No out-of-phase echo modulation is observed. Taken together, the recombination kinetics, the frequency dependence of the spin polarization and the absence of an out-of-phase echo signal lead to the assignment of the spectra to the contribution from P+. to the state P+.F-X. The origin of the net polarization and its frequency dependence are discussed in terms of singlet-triplet mixing in the precursor. It is shown that the field-dependent polarization expected to develop during the 600-700 ps lifetime of P+.A-.0 is in qualitative agreement with the observed spectra. The identity that the acceptor preceding FX and the conflicting evidence from EPR, optical methods and chemical analyses of the samples are discussed.
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Affiliation(s)
- A van der Est
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
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Affiliation(s)
- Marianne L. McKelvy
- Analytical Sciences Laboratory, The Dow Chemical Company, U.S.A., Midland, Michigan 48667, and Applied Extrusion Technologies, 15 Reads Way, Newcastle, Delaware 19720
| | - Thomas R. Britt
- Analytical Sciences Laboratory, The Dow Chemical Company, U.S.A., Midland, Michigan 48667, and Applied Extrusion Technologies, 15 Reads Way, Newcastle, Delaware 19720
| | - Bradley L. Davis
- Analytical Sciences Laboratory, The Dow Chemical Company, U.S.A., Midland, Michigan 48667, and Applied Extrusion Technologies, 15 Reads Way, Newcastle, Delaware 19720
| | - J. Kevin Gillie
- Analytical Sciences Laboratory, The Dow Chemical Company, U.S.A., Midland, Michigan 48667, and Applied Extrusion Technologies, 15 Reads Way, Newcastle, Delaware 19720
| | - Felicia B. Graves
- Analytical Sciences Laboratory, The Dow Chemical Company, U.S.A., Midland, Michigan 48667, and Applied Extrusion Technologies, 15 Reads Way, Newcastle, Delaware 19720
| | - L. Alice Lentz
- Analytical Sciences Laboratory, The Dow Chemical Company, U.S.A., Midland, Michigan 48667, and Applied Extrusion Technologies, 15 Reads Way, Newcastle, Delaware 19720
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