Institut für Chemie/Max Volmer Laboratorium für Biophysikalische Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, D-10623 Berlin, Germany.
J Photochem Photobiol B. 2011 Jul-Aug;104(1-2):19-34. doi: 10.1016/j.jphotobiol.2011.02.025. Epub 2011 Mar 24.
To maintain its functionality, photosystem II (PSII) employs several types of auxiliary molecules (cofactors). As shown for PSII from Thermosynechococcus elongatus, lipids previously thought to play mostly the role of a hydrophobic matrix for embedding the membrane proteins, must be considered as a new, multifunctional type of cofactors, playing a vital role in the fine tuning of PSII and in its overall operation. The 2.9 Å resolution crystal structure of cyanobacterial homodimeric PSII showed the position of 25 lipid molecules per monomer, and allowed detailed analysis of individual binding sites as well as functional aspects related to lipids. The positions of the bound lipids suggest that they are essential for the assembly and disassembly of PSII, provide the proper environment for plastoquinone exchange, might tune electron transfer through contacts with chlorophylls and carotenoids, and might serve as an oxygen-outlet system from the lumen.
为了维持其功能，光系统 II（PSII）采用了几种类型的辅助分子（辅助因子）。如图所示，来自伸长鱼腥蓝细菌的 PSII，以前被认为主要起作为膜蛋白嵌入的疏水性基质作用的脂质，必须被视为一种新的、多功能类型的辅助因子，在 PSII 的精细调节及其整体运作中起着至关重要的作用。2.9Å 分辨率的蓝细菌同源二聚 PSII 晶体结构显示每个单体有 25 个脂质分子的位置，并允许对单个结合位点以及与脂质相关的功能方面进行详细分析。结合脂质的位置表明它们对于 PSII 的组装和拆卸是必不可少的，为质体醌交换提供适当的环境，可能通过与叶绿素和类胡萝卜素的接触来调节电子转移，并可能作为腔从的氧气出口系统。
