7VOR

The structure of dimeric photosynthetic RC-LH1 supercomplex in Class-1

This is a non-PDB format compatible entry.

Summary for 7VOR

• Entry DOI: 10.2210/pdb7vor/pdb
• EMDB information: 32058
• Descriptor: Reaction center protein L chain, UBIQUINONE-10, 1,2-DIACYL-SN-GLYCERO-3-PHOSPHOCHOLINE, ... (14 entities in total)
• Functional Keywords: photosynthesis, supercomplex, purple bacteria
• Biological source: Cereibacter sphaeroides 2.4.1 (Cereibacter sphaeroides); More
• Total number of polymer chains: 66
• Total formula weight: 680087.42

Authors

Cao, P.,Li, M.,Liu, L.N. (deposition date: 2021-10-14, release date: 2022-04-27, Last modification date: 2024-06-19)

Primary citation

Cao, P.,Bracun, L.,Yamagata, A.,Christianson, B.M.,Negami, T.,Zou, B.,Terada, T.,Canniffe, D.P.,Shirouzu, M.,Li, M.,Liu, L.N.
Structural basis for the assembly and quinone transport mechanisms of the dimeric photosynthetic RC-LH1 supercomplex.
Nat Commun, 13:1977-1977, 2022

PubMed 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.

PubMed: 35418573
DOI: 10.1038/s41467-022-29563-3

Experimental method

ELECTRON MICROSCOPY (2.74 Å)