7Y1A

Lateral hexamer

Summary for 7Y1A

• Entry DOI: 10.2210/pdb7y1a/pdb
• EMDB information: 33558
• Descriptor: B-phycoerythrin beta chain, Phycoerythrin alpha subunit, LRH, ... (5 entities in total)
• Functional Keywords: lateral hexamer, pbs, photosynthesis
• Biological source: Porphyridium purpureum; More
• Total number of polymer chains: 14
• Total formula weight: 256904.67

Authors

You, X.,Zhang, X.,Cheng, J.,Xiao, Y.N.,Sun, S.,Sui, S.F. (deposition date: 2022-06-07, release date: 2023-01-18, Last modification date: 2023-04-19)

Primary citation

You, X.,Zhang, X.,Cheng, J.,Xiao, Y.,Ma, J.,Sun, S.,Zhang, X.,Wang, H.W.,Sui, S.F.
In situ structure of the red algal phycobilisome-PSII-PSI-LHC megacomplex.
Nature, 616:199-206, 2023

PubMed Abstract: In oxygenic photosynthetic organisms, light energy is captured by antenna systems and transferred to photosystem II (PSII) and photosystem I (PSI) to drive photosynthesis. The antenna systems of red algae consist of soluble phycobilisomes (PBSs) and transmembrane light-harvesting complexes (LHCs). Excitation energy transfer pathways from PBS to photosystems remain unclear owing to the lack of structural information. Here we present in situ structures of PBS-PSII-PSI-LHC megacomplexes from the red alga Porphyridium purpureum at near-atomic resolution using cryogenic electron tomography and in situ single-particle analysis, providing interaction details between PBS, PSII and PSI. The structures reveal several unidentified and incomplete proteins and their roles in the assembly of the megacomplex, as well as a huge and sophisticated pigment network. This work provides a solid structural basis for unravelling the mechanisms of PBS-PSII-PSI-LHC megacomplex assembly, efficient energy transfer from PBS to the two photosystems, and regulation of energy distribution between PSII and PSI.

PubMed: 36922595
DOI: 10.1038/s41586-023-05831-0

Experimental method

ELECTRON MICROSCOPY (6.3 Å)