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Title | Cryo-EM structure of the Blastochloris viridis LH1-RC complex at 2.9 Å. |
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Journal, issue, pages | Nature, Vol. 556, Issue 7700, Page 203-208, Year 2018 |
Publish date | Apr 4, 2018 |
![]() | Pu Qian / C Alistair Siebert / Peiyi Wang / Daniel P Canniffe / C Neil Hunter / ![]() |
PubMed Abstract | The light-harvesting 1-reaction centre (LH1-RC) complex is a key functional component of bacterial photosynthesis. Here we present a 2.9 Å resolution cryo-electron microscopy structure of the ...The light-harvesting 1-reaction centre (LH1-RC) complex is a key functional component of bacterial photosynthesis. Here we present a 2.9 Å resolution cryo-electron microscopy structure of the bacteriochlorophyll b-based LH1-RC complex from Blastochloris viridis that reveals the structural basis for absorption of infrared light and the molecular mechanism of quinone migration across the LH1 complex. The triple-ring LH1 complex comprises a circular array of 17 β-polypeptides sandwiched between 17 α- and 16 γ-polypeptides. Tight packing of the γ-apoproteins between β-polypeptides collectively interlocks and stabilizes the LH1 structure; this, together with the short Mg-Mg distances of bacteriochlorophyll b pairs, contributes to the large redshift of bacteriochlorophyll b absorption. The 'missing' 17th γ-polypeptide creates a pore in the LH1 ring, and an adjacent binding pocket provides a folding template for a quinone, Q , which adopts a compact, export-ready conformation before passage through the pore and eventual diffusion to the cytochrome bc complex. |
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Methods | EM (single particle) |
Resolution | 2.87 Å |
Structure data | |
Chemicals | ![]() ChemComp-HEM: ![]() ChemComp-BCB: ![]() ChemComp-BPB: ![]() ChemComp-UQ9: ![]() ChemComp-FE: ![]() ChemComp-SO4: ![]() ChemComp-LDA: ![]() ChemComp-MQ9: ![]() ChemComp-NS5: ![]() ChemComp-NS0: |
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![]() | PHOTOSYNTHESIS / Reaction centre light harvesting complex 1 Blc. viridis Cryo-EM RC-LH1 Photosynthesis |