Decrease in the efficiency of the electron donation to tyrosine Z of photosystem II in an SQDG‐deficient mutant of Chlamydomonas

FEBS Letters

Sato, Norihiro¹  Tsuzuki, Mikio¹  Minoda, Ayumi¹  Okada, Katsuhiko¹  Sonoike, Kintake² 

[1] School of Life Science, Tokyo University of Pharmacy and Life Science, Horinouchi, Hachioji, Tokyo 192-0392, Japan;Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa-shi, Chiba 277-8562, Japan

关键词: Sulfoquinovosyl diacylglycerol;    Photosystem II;    Thylakoid membrane;    Glycolipid;    Chlamydomonas;    SQDG;    sulfoquinovosyl diacylglycerol;    PSII;    photosystem II;    DCIP;    2;    6-dichlorophenol indophenol;    DPC;    diphenylcarbazide;    PG;    phosphatidylglycerol;    DCMU;    3-(3;    4-dichlorophenyl)-1;    1-dimethylurea;   

DOI  :  10.1016/S0014-5793(03)00981-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Photosystem (PS) II activity of a sulfoquinovosyl diacylglycerol (SQDG)-deficient mutant (hf-2) of Chlamydomonas was partially decreased compared with that of wild-type. The susceptibility to 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) was also modified in the mutant. Photometric measurements in the isolated thylakoid membranes of hf-2 revealed that the lowered activity in the mutant was derived from a decrease in the efficiency of the electron donation from water to tyrosine Z, not from the efficiency of the electron transport from Q_A to Q_B. This result was confirmed by the decay kinetics of chlorophyll fluorescence determined in vivo. We conclude that SQDG contributes to maintaining the conformation of PSII complexes, particularly that of D1 polypeptides, which are necessary for maximum activities in Chlamydomonas.

【 授权许可】

Unknown