8XKL

Structure of ACPII-CCPII from cryptophyte algae

8XKL の概要

• エントリーDOI: 10.2210/pdb8xkl/pdb
• EMDBエントリー: 38419
• 分子名称: ACPII-4, Chlorophyll c2, (1~{R})-3,5,5-trimethyl-4-[(3~{E},5~{E},7~{E},9~{E},11~{E},13~{E},15~{E},17~{E})-3,7,12,16-tetramethyl-18-(2,6,6-trimethylcyclohexen-1-yl)octadeca-3,5,7,9,11,13,15,17-octaen-1-ynyl]cyclohex-3-en-1-ol, ... (17 entities in total)
• 機能のキーワード: photosystem ii, photosynthesis, structural protein
• 由来する生物種: Chroomonas placoidea; 詳細
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 267612.05

構造登録者

Li, X.Y.,Mao, Z.Y.,Shen, J.R.,Han, G.Y. (登録日: 2023-12-23, 公開日: 2024-06-05)

主引用文献

Mao, Z.,Li, X.,Li, Z.,Shen, L.,Li, X.,Yang, Y.,Wang, W.,Kuang, T.,Shen, J.R.,Han, G.
Structure and distinct supramolecular organization of a PSII-ACPII dimer from a cryptophyte alga Chroomonas placoidea.
Nat Commun, 15:4535-4535, 2024

PubMed Abstract: Cryptophyte algae are an evolutionarily distinct and ecologically important group of photosynthetic unicellular eukaryotes. Photosystem II (PSII) of cryptophyte algae associates with alloxanthin chlorophyll a/c-binding proteins (ACPs) to act as the peripheral light-harvesting system, whose supramolecular organization is unknown. Here, we purify the PSII-ACPII supercomplex from a cryptophyte alga Chroomonas placoidea (C. placoidea), and analyze its structure at a resolution of 2.47 Å using cryo-electron microscopy. This structure reveals a dimeric organization of PSII-ACPII containing two PSII core monomers flanked by six symmetrically arranged ACPII subunits. The PSII core is conserved whereas the organization of ACPII subunits exhibits a distinct pattern, different from those observed so far in PSII of other algae and higher plants. Furthermore, we find a Chl a-binding antenna subunit, CCPII-S, which mediates interaction of ACPII with the PSII core. These results provide a structural basis for the assembly of antennas within the supercomplex and possible excitation energy transfer pathways in cryptophyte algal PSII, shedding light on the diversity of supramolecular organization of photosynthetic machinery.

PubMed: 38806516
DOI: 10.1038/s41467-024-48878-x

実験手法

ELECTRON MICROSCOPY (2.84 Å)