The study on lipid modification of extrinsic proteins and thermotorelance of photosynthesis

本文利用Synechocystis sp. PCC 6803和Anabaena sp. PCC 7120研究了蓝藻光系统II复合体（PSII）的热依赖性机制，重点研究了脂质和外源蛋白在稳定PSII中的作用。研究发现，至少有一种与PSII的还原侧相关的磷脂酰甘油分子不仅通过影响PSII的还原侧，而且通过影响PSII的氧化侧，即外源蛋白与进化氧复合物的功能结合，参与了PSII的稳定。我们制作了一个Anabaena突变体，其中一个组氨酸标签附着在PSII的一个亚基上，以便从细胞中快速分离出高纯度的PSII复合体。

Mechanism of thermotorelance of cyanobacterial photosystem II complex (PSII) has been investigated using Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120 focusing on the role of lipids and extrinsic proteins in stabilization of PSII. It was found that at least one phosphatidylglycerol molecule associated with the reducing side of PSII is involved in the stabilization of PSII through affecting not only the reducing-side but also the oxidizing-side of PSII, namely, functional binding of extrinsic proteins to oxygen-evolving complex. We made an Anabaena mutant in which a histidine-tag was attached to one of subunits of PSII to allow the isolation of highly purified PSII complex rapidly from the cells.