The X‐ray structure of photosystem II reveals a novel electron transport pathway between P680, cytochrome b 559 and the energy‐quenching cation, ChlZ +

FEBS Letters

Brudvig, Gary W.¹  Vasil’ev, Sergej²  Bruce, Doug² 

[1] Department of Chemistry, Yale University, P.O. Box 208107, New Haven, CT 06520-8107, USA;Department of Biological Sciences, Brock University, St. Catharines, ON, Canada L2S 3A1

关键词: Photosynthesis;    Non-photochemical quenching;    Chlorophyll fluorescence;    Excitation energy transfer;    Electron transport;    PS;    photosystem;    Chl;    chlorophyll;    P680;    primary electron donor for photosystem II;    ChlZ(D1) and ChlZ(D2);    peripheral reaction center chlorophylls of photosystem II;    ChlD2;    reaction center chlorophyll of photosystem II;   

DOI  :  10.1016/S0014-5793(03)00442-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

When water oxidation by photosystem II (PSII) is impaired, an oxidized chlorophyll (Chl_Z ⁺) is formed that quenches excitation and may prevent photodamage. Both the identification of this Chl⁺ and the mechanism of its oxidation and reduction are controversial. Using the available X-ray structures of PSII we calculated the efficiency of two proposed quenchers, Chl_Z ⁺(D1) and Chl_Z ⁺(D2). Of these two, only Chl_Z ⁺(D1) can quench to the degree observed experimentally. We also identify a chain of closely spaced pigments in the structure from Thermosynechococcus vulcanus that we propose to form a novel electron transport pathway between Chl_Z(D1), β-carotene, P680⁺ and cytochrome b ₅₅₉.

【 授权许可】

Unknown