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Gisriel CJ. Recent structural discoveries of photosystems I and II acclimated to absorb far-red light. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2024; 1865:149032. [PMID: 38401604 PMCID: PMC11162955 DOI: 10.1016/j.bbabio.2024.149032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/22/2024] [Accepted: 02/09/2024] [Indexed: 02/26/2024]
Abstract
Photosystems I and II are the photooxidoreductases central to oxygenic photosynthesis and canonically absorb visible light (400-700 nm). Recent investigations have revealed that certain cyanobacteria can acclimate to environments enriched in far-red light (700-800 nm), yet can still perform oxygenic photosynthesis in a process called far-red light photoacclimation, or FaRLiP. During this process, the photosystem subunits and pigment compositions are altered. Here, the current structural understanding of the photosystems expressed during FaRLiP is described. The design principles may be useful for guiding efforts to engineer shade tolerance in organisms that typically cannot utilize far-red light.
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Gisriel CJ, Bryant DA, Brudvig GW, Cardona T. Molecular diversity and evolution of far-red light-acclimated photosystem I. FRONTIERS IN PLANT SCIENCE 2023; 14:1289199. [PMID: 38053766 PMCID: PMC10694217 DOI: 10.3389/fpls.2023.1289199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 10/31/2023] [Indexed: 12/07/2023]
Abstract
The need to acclimate to different environmental conditions is central to the evolution of cyanobacteria. Far-red light (FRL) photoacclimation, or FaRLiP, is an acclimation mechanism that enables certain cyanobacteria to use FRL to drive photosynthesis. During this process, a well-defined gene cluster is upregulated, resulting in changes to the photosystems that allow them to absorb FRL to perform photochemistry. Because FaRLiP is widespread, and because it exemplifies cyanobacterial adaptation mechanisms in nature, it is of interest to understand its molecular evolution. Here, we performed a phylogenetic analysis of the photosystem I subunits encoded in the FaRLiP gene cluster and analyzed the available structural data to predict ancestral characteristics of FRL-absorbing photosystem I. The analysis suggests that FRL-specific photosystem I subunits arose relatively late during the evolution of cyanobacteria when compared with some of the FRL-specific subunits of photosystem II, and that the order Nodosilineales, which include strains like Halomicronema hongdechloris and Synechococcus sp. PCC 7335, could have obtained FaRLiP via horizontal gene transfer. We show that the ancestral form of FRL-absorbing photosystem I contained three chlorophyll f-binding sites in the PsaB2 subunit, and a rotated chlorophyll a molecule in the A0B site of the electron transfer chain. Along with our previous study of photosystem II expressed during FaRLiP, these studies describe the molecular evolution of the photosystem complexes encoded by the FaRLiP gene cluster.
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Affiliation(s)
| | - Donald A. Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States
| | - Gary W. Brudvig
- Department of Chemistry, Yale University, New Haven, CT, United States
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Tanai Cardona
- Department of Life Sciences, Imperial College London, London, United Kingdom
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, United Kingdom
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3
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Agarwala N, Makita H, Hastings G. Time-resolved FTIR difference spectroscopy for the study of photosystem I with high potential naphthoquinones incorporated into the A 1 binding site. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148918. [PMID: 36116485 DOI: 10.1016/j.bbabio.2022.148918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/08/2022] [Accepted: 09/11/2022] [Indexed: 11/28/2022]
Abstract
Time-resolved step-scan Fourier transform infrared difference spectroscopy has been used to study cyanobacterial photosystem I photosynthetic reaction centers from Synechocystis sp. PCC 6803 (S6803) with four high-potential, 1,4-naphthoquinones incorporated into the A1 binding site. The high-potential naphthoquinones are 2-chloro-, 2-bromo-, 2,3-dichloro- and 2,3-dibromo-1,4-naphthoquinone. "Foreign minus native" double difference spectra (DDS) were constructed by subtracting difference spectra for native photosystem I (with phylloquinone in the A1 binding site) from corresponding spectra obtained using photosystem I with the different quinones incorporated. To help assess and assign bands in the difference and double difference spectra, density functional theory based vibrational frequency calculations for the different quinones in solvent, or in the presence of a single asymmetric H- bond to either a water molecule or a peptide backbone NH group, were undertaken. Calculated and experimental spectra agree best for the peptide backbone asymmetrically H- bonded system. By comparing multiple sets of double difference spectra, several new bands for the native quinone (phylloquinone) are identified. By comparing calculated and experimental spectra we conclude that the mono-substituted halogenated NQs can occupy the binding site in either of two different orientations, with the chlorine or bromine atom being either ortho or meta to the H- bonded CO group.
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Affiliation(s)
- Neva Agarwala
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, USA
| | - Hiroki Makita
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, USA
| | - Gary Hastings
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, USA.
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Pinevich AV, Averina SG. On the Edge of the Rainbow: Red-Shifted Chlorophylls and Far-Red Light Photoadaptation in Cyanobacteria. Microbiology (Reading) 2022. [DOI: 10.1134/s0026261722602019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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Langley J, Purchase R, Viola S, Fantuzzi A, Davis GA, Shen JR, Rutherford AW, Krausz E, Cox N. Simulating the low-temperature, metastable electrochromism of Photosystem I: Applications to Thermosynechococcus vulcanus and Chroococcidiopsis thermalis. J Chem Phys 2022; 157:125103. [DOI: 10.1063/5.0100431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Low-temperature, metastable electrochromism has been used as a tool to assign pigments in Photosystem I (PS I) from Thermosynechococcus vulcanus and both the white light (WL) and far-red light (FRL) forms of Chroococcidiopsis thermalis. We find a minimum of seven pigments is required to satisfactorily model the electrochromism of PS I. Using our model, we provide a short list of candidates for the chlorophyll f pigment in FRL C. thermalis that absorbs at 756 nm, whose identity to date has proven to be controversial. Specifically, we propose the linker pigments A40 and B39, and two antenna pigments A26 and B24 as defined by crystal structure 1JB0. The pros and cons of these assignments are discussed, and we propose further experiments to better understand the functioning of FRL C. thermalis.
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Affiliation(s)
- Julien Langley
- Australian National University Research School of Chemistry, Australia
| | - Robin Purchase
- Australian National University Research School of Chemistry, Australia
| | | | | | | | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science, Okayama University, Japan
| | | | - Elmars Krausz
- Australian National University, Australian National University Research School of Chemistry, Australia
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Agarwala N, Rohani L, Hastings G. Experimental and calculated infrared spectra of disubstituted naphthoquinones. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 268:120674. [PMID: 34894562 DOI: 10.1016/j.saa.2021.120674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 10/21/2021] [Accepted: 11/26/2021] [Indexed: 06/14/2023]
Abstract
In recent years there has been interest in incorporating substituted 1,4-naphthoquinones (NQs) into the A1 binding site in photosystem I (PSI) photosynthetic protein complexes. This interest in part stems from the considerably altered bioenergetics of electron transfer that occur in PSI with such substitutions. Time resolved FTIR studies of PSI complexes with disubstituted NQs incorporated have and currently are being undertaken, and with this in mind it is worth considering FTIR absorption spectra of these disubstituted NQs in solution. Here we present FTIR absorbance spectra for 2-bromo-3-methyl-1,4-naphthoquinone (BrMeNQ), 2-chloromethyl-3-methyl-1,4-naphthoquinone (CMMeNQ) and 2-ethylthio-3-methyl-1,4-naphthoquinone (ETMeNQ) in tetrahydrofuran (THF). The FTIR spectra of these di-substituted naphthoquinones (NQs) were compared to FTIR spectra of 2-methyl-3-phytyl-1,4-naphthoquinone [phylloquinone (PhQ)], 2,3-dimethyl-1,4-naphthoquinone (DMNQ), and 2-methyl-1,4-naphthoquinone (2MNQ). To aid in the assignment of bands in the experimental spectra, density functional theory (DFT) based vibrational frequency calculations for all the substituted NQs in solution were undertaken. The calculated and experimental spectra agree well. By calculating normal mode potential energy distributions, unambiguous quantitative band assignments were made. The calculated and experimental spectra together make predictions about what may be observable in time resolved FTIR difference spectra obtained using PSI with the different NQs incorporated. Time resolved FTIR difference spectra are presented that support these predictions.
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Affiliation(s)
- Neva Agarwala
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA
| | - Leyla Rohani
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA
| | - Gary Hastings
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303, USA.
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7
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Breaking the Red Limit: Efficient Trapping of Long-Wavelength Excitations in Chlorophyll-f-Containing Photosystem I. Chem 2021. [DOI: 10.1016/j.chempr.2020.10.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Mascoli V, Bersanini L, Croce R. Far-red absorption and light-use efficiency trade-offs in chlorophyll f photosynthesis. NATURE PLANTS 2020; 6:1044-1053. [PMID: 32661277 DOI: 10.1038/s41477-020-0718-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 06/04/2020] [Indexed: 05/28/2023]
Abstract
Plants and cyanobacteria use the chlorophylls embedded in their photosystems to absorb photons and perform charge separation, the first step of converting solar energy to chemical energy. While oxygenic photosynthesis is primarily based on chlorophyll a photochemistry, which is powered by red light, a few cyanobacterial species can harness less energetic photons when growing in far-red light. Acclimatization to far-red light involves the incorporation of a small number of molecules of red-shifted chlorophyll f in the photosystems, whereas the most abundant pigment remains chlorophyll a. Due to its different energetics, chlorophyll f is expected to alter the excited-state dynamics of the photosynthetic units and, ultimately, their performances. Here we combined time-resolved fluorescence measurements on intact cells and isolated complexes to show that chlorophyll f insertion slows down the overall energy trapping in both photosystems. While this marginally affects the efficiency of photosystem I, it substantially decreases that of photosystem II. Nevertheless, we show that despite the lower energy output, the insertion of red-shifted chlorophylls in the photosystems remains advantageous in environments that are enriched in far-red light and therefore represents a viable strategy for extending the photosynthetically active spectrum in other organisms, including plants. However, careful design of the new photosynthetic units will be required to preserve their efficiency.
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Affiliation(s)
- Vincenzo Mascoli
- Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Luca Bersanini
- Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Roberta Croce
- Department of Physics and Astronomy and Institute for Lasers, Life and Biophotonics, Faculty of Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
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Agarwala N, Makita H, Luo L, Xu W, Hastings G. Reversible inhibition and reactivation of electron transfer in photosystem I. PHOTOSYNTHESIS RESEARCH 2020; 145:97-109. [PMID: 32447611 DOI: 10.1007/s11120-020-00760-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
In photosystem I (PSI) complexes at room temperature electron transfer from A1- to FX is an order of magnitude faster on the B-branch compared to the A-branch. One factor that might contribute to this branch asymmetry in time constants is TrpB673 (Thermosynechococcus elongatus numbering), which is located between A1B and FX. The corresponding residue on the A-branch, between A1A and FX, is GlyA693. Here, microsecond time-resolved step-scan FTIR difference spectroscopy at 77 K has been used to study isolated PSI complexes from wild type and TrpB673Phe mutant (WB673F mutant) cells from Synechocystis sp. PCC 6803. WB673F mutant cells require glucose for growth and are light sensitive. Photoaccumulated FTIR difference spectra indicate changes in amide I and II protein vibrations upon mutation of TrpB673 to Phe, indicating the protein environment near FX is altered upon mutation. In the WB673F mutant PSI samples, but not in WT PSI samples, the phylloquinone molecule that occupies the A1 binding site is likely doubly protonated following long periods of repetitive flash illumination at room temperature. PSI with (doubly) protonated quinone in the A1 binding site are not functional in electron transfer. However, electron transfer functionality can be restored by incubating the light-treated mutant PSI samples in the presence of added phylloquinone.
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Affiliation(s)
- Neva Agarwala
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30303, USA
| | - Hiroki Makita
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30303, USA
| | - Lujun Luo
- Department of Chemistry, University of Louisiana At Lafayette, Lafayette, LA, 70503, USA
| | - Wu Xu
- Department of Chemistry, University of Louisiana At Lafayette, Lafayette, LA, 70503, USA
| | - Gary Hastings
- Department of Physics and Astronomy, Georgia State University, Atlanta, GA, 30303, USA.
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10
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Gisriel CJ, Wang J, Brudvig GW, Bryant DA. Opportunities and challenges for assigning cofactors in cryo-EM density maps of chlorophyll-containing proteins. Commun Biol 2020; 3:408. [PMID: 32733087 PMCID: PMC7393486 DOI: 10.1038/s42003-020-01139-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 07/10/2020] [Indexed: 01/21/2023] Open
Abstract
The accurate assignment of cofactors in cryo-electron microscopy maps is crucial in determining protein function. This is particularly true for chlorophylls (Chls), for which small structural differences lead to important functional differences. Recent cryo-electron microscopy structures of Chl-containing protein complexes exemplify the difficulties in distinguishing Chl b and Chl f from Chl a. We use these structures as examples to discuss general issues arising from local resolution differences, properties of electrostatic potential maps, and the chemical environment which must be considered to make accurate assignments. We offer suggestions for how to improve the reliability of such assignments. In this Perspective, Christopher Gisriel et al. discuss the challenges in accurate assignment of co-factors in cryo-EM, particularly for chlorophylls. They explore the factors that lead to misassignment and offer suggestions for improving reliability of cryo-EM-based assignments.
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Affiliation(s)
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, CT, 06520, USA.,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA.,Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, 59717, USA
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11
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Evidence that chlorophyll f functions solely as an antenna pigment in far-red-light photosystem I from Fischerella thermalis PCC 7521. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148184. [PMID: 32179058 DOI: 10.1016/j.bbabio.2020.148184] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 02/21/2020] [Accepted: 03/09/2020] [Indexed: 11/20/2022]
Abstract
The Photosystem I (PSI) reaction center in cyanobacteria is comprised of ~96 chlorophyll (Chl) molecules, including six specialized Chl molecules denoted Chl1A/Chl1B (P700), Chl2A/Chl2B, and Chl3A/Chl3B that are arranged in two branches and function in primary charge separation. It has recently been proposed that PSI from Chroococcidiopsis thermalis (Nürnberg et al. (2018) Science 360, 1210-1213) and Fischerella thermalis PCC 7521 (Hastings et al. (2019) Biochim. Biophys. Acta 1860, 452-460) contain Chl f in the positions Chl2A/Chl2B. We tested this proposal by exciting RCs from white-light grown (WL-PSI) and far-red light grown (FRL-PSI) F. thermalis PCC 7521 with femtosecond pulses and analyzing the optical dynamics. If Chl f were in the position Chl2A/Chl2B in FRL-PSI, excitation at 740 nm should have produced the charge-separated state P700+A0- followed by electron transfer to A1 with a τ of ≤25 ps. Instead, it takes ~230 ps for the charge-separated state to develop because the excitation migrates uphill from Chl f in the antenna to the trapping center. Further, we observe a strong electrochromic shift at 685 nm in the final P700+A1- spectrum that can only be explained if Chl a is in the positions Chl2A/Chl2B. Similar arguments rule out the presence of Chl f in the positions Chl3A/Chl3B; hence, Chl f is likely to function solely as an antenna pigment in FRL-PSI. We additionally report the presence of an excitonically coupled homo- or heterodimer of Chl f absorbing around 790 nm that is kinetically independent of the Chl f population that absorbs around 740 nm.
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12
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Gisriel C, Shen G, Kurashov V, Ho MY, Zhang S, Williams D, Golbeck JH, Fromme P, Bryant DA. The structure of Photosystem I acclimated to far-red light illuminates an ecologically important acclimation process in photosynthesis. SCIENCE ADVANCES 2020; 6:eaay6415. [PMID: 32076649 PMCID: PMC7002129 DOI: 10.1126/sciadv.aay6415] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 12/03/2019] [Indexed: 06/01/2023]
Abstract
Phototrophic organisms are superbly adapted to different light environments but often must acclimate to challenging competition for visible light wavelengths in their niches. Some cyanobacteria overcome this challenge by expressing paralogous photosynthetic proteins and by synthesizing and incorporating ~8% chlorophyll f into their Photosystem I (PSI) complexes, enabling them to grow under far-red light (FRL). We solved the structure of FRL-acclimated PSI from the cyanobacterium Fischerella thermalis PCC 7521 by single-particle, cryo-electron microscopy to understand its structural and functional differences. Four binding sites occupied by chlorophyll f are proposed. Subtle structural changes enable FRL-adapted PSI to extend light utilization for oxygenic photosynthesis to nearly 800 nm. This structure provides a platform for understanding FRL-driven photosynthesis and illustrates the robustness of adaptive and acclimation mechanisms in nature.
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Affiliation(s)
- Christopher Gisriel
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ 85287-5001, USA
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287-1604, USA
| | - Gaozhong Shen
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802 USA
| | - Vasily Kurashov
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802 USA
| | - Ming-Yang Ho
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802 USA
- Intercollege Graduate Program in Plant Biology, The Pennsylvania State University, University Park, PA 16802 USA
| | - Shangji Zhang
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ 85287-5001, USA
| | - Dewight Williams
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ 85287-5001, USA
| | - John H. Golbeck
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802 USA
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802 USA
| | - Petra Fromme
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ 85287-5001, USA
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287-1604, USA
| | - Donald A. Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802 USA
- Intercollege Graduate Program in Plant Biology, The Pennsylvania State University, University Park, PA 16802 USA
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717 USA
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13
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Kato K, Shinoda T, Nagao R, Akimoto S, Suzuki T, Dohmae N, Chen M, Allakhverdiev SI, Shen JR, Akita F, Miyazaki N, Tomo T. Structural basis for the adaptation and function of chlorophyll f in photosystem I. Nat Commun 2020; 11:238. [PMID: 31932639 PMCID: PMC6957486 DOI: 10.1038/s41467-019-13898-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 12/05/2019] [Indexed: 12/03/2022] Open
Abstract
Chlorophylls (Chl) play pivotal roles in energy capture, transfer and charge separation in photosynthesis. Among Chls functioning in oxygenic photosynthesis, Chl f is the most red-shifted type first found in a cyanobacterium Halomicronema hongdechloris. The location and function of Chl f in photosystems are not clear. Here we analyzed the high-resolution structures of photosystem I (PSI) core from H. hongdechloris grown under white or far-red light by cryo-electron microscopy. The structure showed that, far-red PSI binds 83 Chl a and 7 Chl f, and Chl f are associated at the periphery of PSI but not in the electron transfer chain. The appearance of Chl f is well correlated with the expression of PSI genes induced under far-red light. These results indicate that Chl f functions to harvest the far-red light and enhance uphill energy transfer, and changes in the gene sequences are essential for the binding of Chl f. Chlorophyll f (Chl f) is the most red-shifted Chl in oxygenic photosynthesis but its localization in photosystem I (PSI) has been unknown so far. Here the authors determine the cryo-EM structures of PSI complexes from a Chl f-containing cyanobacterium grown either under white light or far-red light conditions and identify seven Chls f in the far-red light PSI structure, whereas PSI from cells grown under white light contains only Chl a.
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Affiliation(s)
- Koji Kato
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Toshiyuki Shinoda
- Faculty of Science, Tokyo University of Science, Tokyo, 162-8601, Japan
| | - Ryo Nagao
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Seiji Akimoto
- Graduate School of Science, Kobe University, Kobe, 657-8501, Japan
| | - Takehiro Suzuki
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Wako, Japan
| | - Naoshi Dohmae
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Wako, Japan
| | - Min Chen
- School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Suleyman I Allakhverdiev
- K.A. Timiryazev Institute of Plant Physiology RAS, Moscow, Russia.,Institute of Basic Biological Problems RAS, Pushchino, Moscow Region, Russia.,M.V. Lomonosov Moscow State University, Moscow, Russia.,Moscow Institute of Physics and Technology, Dolgoprudny, Moscow region, Russia.,Institute of Molecular Biology and Biotechnology ANAS, -Baku, Azerbaijan
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.
| | - Fusamichi Akita
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan. .,Japan Science and Technology Agency, PRESTO, Saitama, 332-0012, Japan.
| | - Naoyuki Miyazaki
- Institute for Protein Research, Laboratory of Protein Synthesis and Expression, Osaka University, Osaka, 565-0871, Japan. .,Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance, University of Tsukuba, Ibaraki, 305-8577, Japan.
| | - Tatsuya Tomo
- Faculty of Science, Tokyo University of Science, Tokyo, 162-8601, Japan.
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