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Structure of the plant photosystem I supercomplex at 2.6 Å resolution

Abstract

Four elaborate membrane complexes carry out the light reaction of oxygenic photosynthesis. Photosystem I (PSI) is one of two large reaction centres responsible for converting light photons into the chemical energy needed to sustain life. In the thylakoid membranes of plants, PSI is found together with its integral light-harvesting antenna, light-harvesting complex I (LHCI), in a membrane supercomplex containing hundreds of light-harvesting pigments. Here, we report the crystal structure of plant PSI–LHCI at 2.6 Å resolution. The structure reveals the configuration of PsaK, a core subunit important for state transitions in plants, a conserved network of water molecules surrounding the electron transfer centres and an elaborate structure of lipids bridging PSI and its LHCI antenna. We discuss the implications of the structure for energy transfer and the evolution of PSI.

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Figure 1: The structure of plant PSI–LHCI at 2.6 Å resolution.
Figure 2: The structure of the PsaK subunit suggests multiple conformations.
Figure 3: Lipid structure in PSI–LHCI, core asymmetry and a complete patch of lipids in the PSI–LHCI gap.
Figure 4: A small region determines the oligomeric state of LHC proteins.
Figure 5: Chlorophyll b molecules are located at the junctions of individual lhca subunits.
Figure 6: Chlorophyll b molecules are coordinated by a mixture of polar and hydrophobic interactions.
Figure 7: Förster rate calculations reveal the importance of the luminal-side pigment junctions.

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References

  1. Blankenship, R. E. Origin and early evolution of photosynthesis. Photosynth. Res. 33, 91–111 (1992).

    Article  CAS  Google Scholar 

  2. Barber, J. Engine of life and big bang of evolution: a personal perspective. Photosynth. Res. 80, 137–155 (2004).

    Article  CAS  Google Scholar 

  3. Nelson, N. Evolution of photosystem I and the control of global enthalpy in an oxidizing world. Photosynth. Res. 116, 145–151 (2013).

    Article  CAS  Google Scholar 

  4. Rensing, S. A. et al. The Physcomitrella genome reveals evolutionary insights into the conquest of land by plants. Science 319, 64–69 (2008).

    Article  CAS  Google Scholar 

  5. Nelson, N. & Yocum, C. F. Structure and function of photosystems I and II. Annu. Rev. Plant Biol. 57, 521–565 (2006).

    Article  CAS  Google Scholar 

  6. Croce, R. & van Amerongen, H. Light-harvesting in photosystem I. Photosynth. Res. 116, 153–166 (2013).

    Article  CAS  Google Scholar 

  7. Nelson, N. & Junge, W. Structure and energy transfer in photosystems of oxygenic photosynthesis. Annu. Rev. Biochem. 84, 659–683 (2015).

    Article  CAS  Google Scholar 

  8. Jordan, P. et al. Three-dimensional structure of cyanobacterial photosystem I at 2.5 Å resolution. Nature 411, 909–917 (2001).

    Article  CAS  Google Scholar 

  9. Ben-Shem, A., Frolow, F. & Nelson, N. Crystal structure of plant photosystem I. Nature 426, 630–635 (2003).

    Article  CAS  Google Scholar 

  10. Umena, Y., Kawakami, K., Shen, J. R. & Kamiya, N. Crystal structure of oxygen-evolving photosystem II at a resolution of 1.9 Å. Nature 473, 55–60 (2011).

    Article  CAS  Google Scholar 

  11. Wei, X. et al. Structure of spinach photosystem II-LHCII supercomplex at 3.2 Å resolution. Nature 534, 69–74 (2016).

    Article  CAS  Google Scholar 

  12. Mazor, Y., Borovikova, A. & Nelson, N. The structure of plant photosystem I super-complex at 2.8 Å resolution. eLife 4, e07433 (2015).

    Article  Google Scholar 

  13. Qin, X., Suga, M., Kuang, T. & Shen, J. R. Photosynthesis. Structural basis for energy transfer pathways in the plant PSI–LHCI supercomplex. Science 348, 989–995 (2015).

    Article  CAS  Google Scholar 

  14. Le Quiniou, C. et al. PSI–LHCI of Chlamydomonas reinhardtii: increasing the absorption cross section without losing efficiency. Biochim. Biophys. Acta 1847, 458–467 (2015).

    Article  CAS  Google Scholar 

  15. Rochaix, J. D. Regulation and dynamics of the light-harvesting system. Annu. Rev. Plant Biol. 65, 287–309 (2014).

    Article  CAS  Google Scholar 

  16. Weinert, T. et al. Fast native-SAD phasing for routine macromolecular structure determination. Nat. Methods 12, 131–133 (2015).

    Article  CAS  Google Scholar 

  17. Mazor, Y., Nataf, D., Toporik, H. & Nelson, N. Crystal structures of virus-like photosystem I complexes from the mesophilic cyanobacterium Synechocystis PCC 6803. eLife 3, e01496 (2014).

    Article  Google Scholar 

  18. Guergova-Kuras, M., Boudreaux, B., Joliot, A., Joliot, P. & Redding, K. Evidence for two active branches for electron transfer in photosystem I. Proc. Natl Acad. Sci. USA 98, 4437–4442 (2001).

    Article  CAS  Google Scholar 

  19. Sharon, I. et al. Photosystem I gene cassettes are present in marine virus genomes. Nature 461, 258–262 (2009).

    Article  CAS  Google Scholar 

  20. Jensen, P. E., Gilpin, M., Knoetzel, J. & Scheller, H. V. The PSI-K subunit of photosystem I is involved in the interaction between light-harvesting complex I and the photosystem I reaction center core. J. Biol. Chem. 275, 24701–24708 (2000).

    Article  CAS  Google Scholar 

  21. Kouril, R. et al. Structural characterization of a complex of photosystem I and light-harvesting complex II of Arabidopsis thaliana. Biochemistry 44, 10935–10940 (2005).

    Article  CAS  Google Scholar 

  22. Gounaris, K. & Barber, J. Monogalactosyldiacylglycerol: the most abundant polar lipid in nature. Trends Biochem. Sci. 8, 378–381 (1983).

    Article  CAS  Google Scholar 

  23. Amunts, A., Drory, O. & Nelson, N. The structure of a plant photosystem I supercomplex at 3.4 Å resolution. Nature 447, 58–63 (2007).

    Article  CAS  Google Scholar 

  24. Sato, N., Suda, K. & Tsuzuki, M. Responsibility of phosphatidylglycerol for biogenesis of the PSI complex. Biochim. Biophys. Acta 1658, 235–243 (2004).

    Article  CAS  Google Scholar 

  25. Block, M. A., Douce, R., Joyard, J. & Rolland, N. Chloroplast envelope membranes: a dynamic interface between plastids and the cytosol. Photosynth. Res. 92, 225–244 (2007).

    Article  CAS  Google Scholar 

  26. Bishop, D. G., Kenrick, J. R., Bayston, J. H., Macpherson, A. S. & Johns, S. R. Monolayer properties of chloroplast lipids. Biochim. Biophys. Acta 602, 248–259 (1980).

    Article  CAS  Google Scholar 

  27. Jansson, S. A guide to the Lhc genes and their relatives in Arabidopsis. Trends Plant. Sci. 4, 236–240 (1999).

    Article  CAS  Google Scholar 

  28. Kargul, J. et al. Light-harvesting complex II protein CP29 binds to photosystem I of Chlamydomonas reinhardtii under State 2 conditions. FEBS J. 272, 4797–4806 (2005).

    Article  CAS  Google Scholar 

  29. Liu, Z. et al. Crystal structure of spinach major light-harvesting complex at 2.72 Å resolution. Nature 428, 287–292 (2004).

    Article  CAS  Google Scholar 

  30. Standfuss, J., Terwisscha van Scheltinga, A. C., Lamborghini, M. & Kühlbrandt, W. Mechanisms of photoprotection and nonphotochemical quenching in pea light-harvesting complex at 2.5 Å resolution. EMBO J. 24, 919–928 (2005).

    Article  CAS  Google Scholar 

  31. Wientjes, E., van Stokkum, I. H., van Amerongen, H. & Croce, R. Excitation-energy transfer dynamics of higher plant photosystem I light-harvesting complexes. Biophys. J. 100, 1372–1380 (2011).

    Article  CAS  Google Scholar 

  32. Morosinotto, T., Breton, J., Bassi, R. & Croce, R. The nature of a chlorophyll ligand in Lhca proteins determines the far red fluorescence emission typical of photosystem I. J. Biol. Chem. 278, 49223–9 (2003).

    Article  CAS  Google Scholar 

  33. Morosinotto, T., Mozzo, M., Bassi, R. & Croce, R. Pigment-pigment interactions in Lhca4 antenna complex of higher plants photosystem I. J. Biol. Chem. 280, 20612–20619 (2005).

    Article  CAS  Google Scholar 

  34. Mozzo, M., Morosinotto, T., Bassi, R. & Croce, R. Probing the structure of Lhca3 by mutation analysis. Biochim. Biophys. Acta. 1757, 1607–1613 (2006).

    Article  CAS  Google Scholar 

  35. Wientjes, E., Roest, G. & Croce, R. From red to blue to far-red in Lhca4: how does the protein modulate the spectral properties of the pigments? Biochim. Biophys. Acta. 1817, 711–717 (2012).

    Article  CAS  Google Scholar 

  36. Morosinotto, T., Castelletti, S., Breton, J., Bassi, R. & Croce, R. Mutation analysis of Lhca1 antenna complex. Low energy absorption forms originate from pigment-pigment interactions. J. Biol. Chem. 277, 36253–36261 (2002).

    Article  CAS  Google Scholar 

  37. Förster, T. Ein beitrag zur theorie der photosynthese. Z. Naturforsch. 2b, 174–182 (1947).

  38. Gradinaru, C. C. et al. The flow of excitation energy in LHCII monomers: implications for the structural model of the major plant antenna. Biophys. J. 75, 3064–3077 (1998).

    Article  CAS  Google Scholar 

  39. van Oort, B. et al. Picosecond fluorescence of intact and dissolved PSI–LHCI crystals. Biophys. J. 95, 5851–5861 (2008).

    Article  CAS  Google Scholar 

  40. Foadi, J. et al. Clustering procedures for the optimal selection of data sets from multiple crystals in macromolecular crystallography. Acta Crystallogr. D 69, 1617–1632 (2013).

    Article  CAS  Google Scholar 

  41. Giordano, R., Leal, R. M., Bourenkov, G. P., McSweeney, S. & Popov, A. N. The application of hierarchical cluster analysis to the selection of isomorphous crystals. Acta Crystallogr. D 68, 649–658 (2012).

    Article  CAS  Google Scholar 

  42. Pape, T. & Schneider, T. R. HKL2MAP: a graphical user interface for macromolecular phasing with SHELX programs. J. Appl. Crystallogr. 37, 843–844 (2004).

    Article  CAS  Google Scholar 

  43. Sheldrick, G. M. A short history of SHELX. Acta Crystallogr. A 64, 112–122 (2008).

    Article  CAS  Google Scholar 

  44. McCoy, A. J. et al. Phaser crystallographic software. J. Appl. Crystallogr. 40, 658–674 (2007).

    Article  CAS  Google Scholar 

  45. Adams, P. D. et al. PHENIX: a comprehensive Python-based system for macromolecular structure solution. Acta Crystallogr. D 66, 213–221 (2010).

    Article  CAS  Google Scholar 

  46. Afonine, P. V., Headd, J. J., Terwilliger, T. C. & Adams, P. D. New tool: phenix.real_space_refine. Comput. Crystallogr. News 4, 36–42 (2013).

    Google Scholar 

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Acknowledgements

The authors would like to thank the ESRF, SLS and BESSYII synchrotrons for beam time and the staff scientists for excellent guide and relentless help. We would like to thank O. Rog for critical reading of the manuscript. This work is supported by a grant no. 293579—HOPSEP from the European Research Council, The Israel Science Foundation through grant no. 71/14 and by the I-CORE Program of the Planning and Budgeting Committee and The Israel Science Foundation (grant no. 1775/12).

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Y.M and N.N. performed experiments, analysed the data and wrote the paper. I.C. analysed the data. A.B. performed experiments.

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Correspondence to Yuval Mazor or Nathan Nelson.

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The authors declare no competing financial interests.

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Supplementary Figures 1–5, Supplementary Tables 1–3, Supplementary References. (PDF 1745 kb)

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Mazor, Y., Borovikova, A., Caspy, I. et al. Structure of the plant photosystem I supercomplex at 2.6 Å resolution. Nature Plants 3, 17014 (2017). https://doi.org/10.1038/nplants.2017.14

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