8WNW

the structure of PsaQ

Summary for 8WNW

• Entry DOI: 10.2210/pdb8wnw/pdb
• EMDB information: 37674
• Descriptor: PsaQ, 1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE, CHLOROPHYLL A, ... (4 entities in total)
• Functional Keywords: photosynthesis, chlorophyll, alloxanthin, growth phase
• Biological source: Rhodomonas salina
• Total number of polymer chains: 1
• Total formula weight: 26408.53

Authors

Zhang, S.M.,Si, L.,Li, M. (deposition date: 2023-10-06, release date: 2024-05-29)

Primary citation

Zhang, S.,Si, L.,Su, X.,Zhao, X.,An, X.,Li, M.
Growth phase-dependent reorganization of cryptophyte photosystem I antennae.
Commun Biol, 7:560-560, 2024

PubMed Abstract: Photosynthetic cryptophytes are eukaryotic algae that utilize membrane-embedded chlorophyll a/c binding proteins (CACs) and lumen-localized phycobiliproteins (PBPs) as their light-harvesting antennae. Cryptophytes go through logarithmic and stationary growth phases, and may adjust their light-harvesting capability according to their particular growth state. How cryptophytes change the type/arrangement of the photosynthetic antenna proteins to regulate their light-harvesting remains unknown. Here we solve four structures of cryptophyte photosystem I (PSI) bound with CACs that show the rearrangement of CACs at different growth phases. We identify a cryptophyte-unique protein, PsaQ, which harbors two chlorophyll molecules. PsaQ specifically binds to the lumenal region of PSI during logarithmic growth phase and may assist the association of PBPs with photosystems and energy transfer from PBPs to photosystems.

PubMed: 38734819
DOI: 10.1038/s42003-024-06268-5

Experimental method

ELECTRON MICROSCOPY (3.5 Å)