Remy André, Niklas Jens, Kuhl Helena, Kellers Petra, Schott Thomas, Rögner Matthias, Gerwert Klaus
Lehrstuhl für Biophysik, Ruhr-Universität Bochum, Germany.
Eur J Biochem. 2004 Feb;271(3):563-7. doi: 10.1046/j.1432-1033.2003.03958.x.
Photosystem II (PSII), an essential component of oxygenic photosynthesis, is a membrane-bound pigment protein complex found in green plants and cyanobacteria. Whereas the molecular structure of cyanobacterial PSII has been resolved with at least medium resolution [Zouni, A., Witt, H.-T., Kern, J., Fromme, P., Krauss, N., Saenger, W. & Orth, P. (2001) Nature (London) 409, 739-743; Kamiya, N. & Shen, J.R. (2003) Proc. Natl Acad. Sci. USA 100, 98-103], the structure of higher plant PSII is only known at low resolution. Therefore Fourier transform infrared (FTIR) difference spectroscopy was used to compare PSII from both Thermosynechococcus elongatus and Synechocystis PCC6803 core complexes with PSII-enriched membranes from spinach (BBY). FTIR difference spectra of T. elongatus core complexes are presented for several different intermediates. As the FTIR difference spectra show close similarities among the three species, the structural arrangement of cofactors in PSII and their interactions with the protein microenvironment during photosynthetic charge separation must be very similar in higher plant PSII and cyanobacterial PSII. A structural model of higher plant PSII can therefore be predicted from the structure of cyanobacterial PSII.
光系统II（PSII）是产氧光合作用的重要组成部分，是一种存在于绿色植物和蓝细菌中的膜结合色素蛋白复合体。虽然蓝细菌PSII的分子结构已至少以中等分辨率解析出来[祖尼，A.，维特，H.-T.，克恩，J.，弗罗梅，P.，克劳斯，N.，森格，W.和奥尔特，P.（2001年）《自然》（伦敦）409，739–743；神谷，N.和沈，J.R.（2003年）《美国国家科学院院刊》100，98–103]，但高等植物PSII的结构仅在低分辨率下已知。因此，利用傅里叶变换红外（FTIR）差示光谱法，将嗜热栖热菌和聚球藻PCC6803核心复合体中的PSII与菠菜（BBY）富含PSII的膜进行比较。给出了嗜热栖热菌核心复合体在几种不同中间体状态下的FTIR差示光谱。由于FTIR差示光谱显示这三种物种之间有密切的相似性，因此在高等植物PSII和蓝细菌PSII中，PSII中辅因子的结构排列及其在光合电荷分离过程中与蛋白质微环境的相互作用一定非常相似。因此，可以根据蓝细菌PSII的结构预测高等植物PSII的结构模型。
