Cao, Peng, Bracun, Laura, Yamagata, Atsushi, Christianson, Bern M, Negami, Tatsuki, Zou, Baohua, Terada, Tohru, Canniffe, Daniel P 
ORCID: 0000-0002-5022-0437, Shirouzu, Mikako, Li, Mei et al (show 1 more authors)
(2022)
Structural basis for the assembly and quinone transport mechanisms of the dimeric photosynthetic RC-LH1 supercomplex
NATURE COMMUNICATIONS, 13 (1).
1977-.
ISSN 2041-1723, 2041-1723
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Text
2022 sphaeroide RC-LH_NC.pdf - Published version Download (3MB) | Preview |
Abstract
The reaction center (RC) and light-harvesting complex 1 (LH1) form a RC–LH1 core supercomplex that is vital for the primary reactions of photosynthesis in purple phototrophic bacteria. Some species possess the dimeric RC–LH1 complex with a transmembrane polypeptide PufX, representing the largest photosynthetic complex in anoxygenic phototrophs. However, the details of the architecture and assembly mechanism of the RC–LH1 dimer are unclear. Here we report seven cryo-electron microscopy (cryo-EM) structures of RC–LH1 supercomplexes from Rhodobacter sphaeroides. Our structures reveal that two PufX polypeptides are positioned in the center of the S-shaped RC–LH1 dimer, interlocking association between the components and mediating RC–LH1 dimerization. Moreover, we identify another transmembrane peptide, designated PufY, which is located between the RC and LH1 subunits near the LH1 opening. PufY binds a quinone molecule and prevents LH1 subunits from completely encircling the RC, creating a channel for quinone/quinol exchange. Genetic mutagenesis, cryo-EM structures, and computational simulations provide a mechanistic understanding of the assembly and electron transport pathways of the RC–LH1 dimer and elucidate the roles of individual components in ensuring the structural and functional integrity of the photosynthetic supercomplex.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Rhodobacter sphaeroides, Benzoquinones, Light-Harvesting Protein Complexes, Photosynthetic Reaction Center Complex Proteins, Peptides, Bacterial Proteins, Cryoelectron Microscopy, Photosynthesis, Models, Molecular |
| Divisions: | Faculty of Health & Life Sciences Faculty of Health & Life Sciences > Inst. Systems, Molec & Integrative Biology > Inst. Systems, Molec & Integrative Biology |
| Depositing User: | Symplectic Admin |
| Date Deposited: | 19 Apr 2022 09:54 |
| Last Modified: | 16 Jun 2026 09:49 |
| DOI: | 10.1038/s41467-022-29563-3 |
| Related Websites: | |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3153307 |
| Disclaimer: | The University of Liverpool is not responsible for content contained on other websites from links within repository metadata. Please contact us if you notice anything that appears incorrect or inappropriate. |
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