Qian, Pu, Siebert, C Alistair, Wang, Peiyi, Canniffe, Daniel P ORCID: 0000-0002-5022-0437 and Hunter, C Neil
(2018)
Cryo-EM structure of the Blastochloris viridis LH1-RC complex at 2.9 angstrom.
NATURE, 556 (7700).
pp. 203-208.
Text
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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 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 P, which adopts a compact, export-ready conformation before passage through the pore and eventual diffusion to the cytochrome bc 1 complex.
Item Type: | Article |
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Uncontrolled Keywords: | Hyphomicrobiaceae, Magnesium, Benzoquinones, Bacteriochlorophylls, Light-Harvesting Protein Complexes, Apoproteins, Bacterial Proteins, Cryoelectron Microscopy, Photosynthesis, Binding Sites, Protein Conformation, Models, Molecular, Protein Stability |
Depositing User: | Symplectic Admin |
Date Deposited: | 08 May 2019 09:11 |
Last Modified: | 19 Jan 2023 01:05 |
DOI: | 10.1038/s41586-018-0014-5 |
Related URLs: | |
URI: | https://livrepository.liverpool.ac.uk/id/eprint/3032075 |