8BD3

Cryo-EM structure of the Photosystem II - LHCII supercomplex from Chlorella ohadi

これはPDB形式変換不可エントリーです。

8BD3 の概要

• エントリーDOI: 10.2210/pdb8bd3/pdb
• EMDBエントリー: 15973
• 分子名称: Chlorophyll a-b binding protein, chloroplastic, Cytochrome b559 subunit beta, Photosystem II reaction center protein H, ... (49 entities in total)
• 機能のキーワード: green alga, psii, c.ohadi, membrane protein, cryo-em, photosynthesis
• 由来する生物種: Chlorella ohadii; 詳細
• タンパク質・核酸の鎖数: 66
• 化学式量合計: 1723567.67

構造登録者

Fadeeva, M.,Klaiman, D.,Caspy, I.,Nelson, N. (登録日: 2022-10-18, 公開日: 2023-08-09, 最終更新日: 2023-08-23)

主引用文献

Fadeeva, M.,Klaiman, D.,Caspy, I.,Nelson, N.
Structure of Chlorella ohadii Photosystem II Reveals Protective Mechanisms against Environmental Stress.
Cells, 12:-, 2023

PubMed Abstract: Green alga is known for its ability to carry out photosynthesis under harsh conditions. Using cryogenic electron microscopy (cryoEM), we obtained a high-resolution structure of PSII at 2.72 Å. This structure revealed 64 subunits, which encompassed 386 chlorophylls, 86 carotenoids, four plastoquinones, and several structural lipids. At the luminal side of PSII, a unique subunit arrangement was observed to protect the oxygen-evolving complex. This arrangement involved PsbO (OEE1), PsbP (OEE2), PsbB, and PsbU (a homolog of plant OEE3). PsbU interacted with PsbO, PsbC, and PsbP, thereby stabilizing the shield of the oxygen-evolving complex. Significant changes were also observed at the stromal electron acceptor side. PsbY, identified as a transmembrane helix, was situated alongside PsbF and PsbE, which enclosed cytochrome . Supported by the adjacent C-terminal helix of Psb10, these four transmembrane helices formed a bundle that shielded cytochrome from the surrounding solvent. Moreover, the bulk of Psb10 formed a protective cap, which safeguarded the quinone site and likely contributed to the stacking of PSII complexes. Based on our findings, we propose a protective mechanism that prevents Q (plastoquinone B) from becoming fully reduced. This mechanism offers insights into the regulation of electron transfer within PSII.

PubMed: 37566050
DOI: 10.3390/cells12151971

実験手法

ELECTRON MICROSCOPY (2.73 Å)