Cao, Peng, Bracun, Laura 
ORCID: 0000-0001-7698-3718, 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-.
|
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 and Life Sciences Faculty of Health and Life Sciences > Institute of Systems, Molecular and Integrative Biology |
| Depositing User: | Symplectic Admin |
| Date Deposited: | 19 Apr 2022 09:54 |
| Last Modified: | 18 Jan 2023 21:05 |
| DOI: | 10.1038/s41467-022-29563-3 |
| Related URLs: | |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3153307 |
Altmetric
Altmetric
