Crystal structure of the PsbQ protein of photosystem II from higher plants
Crystal structure of the PsbQ protein of photosystem II from higher plants
复制标题
DOI：
10.1038/sj.embor.embor923
复制
发表时间：
2003-09-01
期刊：
影响因子：
7.7
通讯作者：
Zanotti, G
中科院分区：
文献类型：
--
作者：
Calderone, V;Trabucco, M;Zanotti, G
从菠菜（Spinacia oleracea）光系统II（PSII）膜中提取并纯化了水氧化复合物（PsbQ）的最小外源多肽。然后在Zn 2+存在下结晶，并使用多波长异常衍射方法通过X射线衍射以1.95埃分辨率确定其结构，其中锌作为异常散射体。晶体结构表明，蛋白质的核心是一个四螺旋束，而氨基末端部分，可能与光系统核心相互作用，是不可见的晶体。蛋白质表面的正、负电荷分布可能解释了PsbQ增加Cl-和Ca ~（2+）结合并使其可用于PSII的能力。
The smallest extrinsic polypeptide of the water-oxidizing complex (PsbQ) was extracted and purified from spinach ( Spinacia oleracea) photosystem II ( PSII) membranes. It was then crystallized in the presence of Zn2+ and its structure was determined by X-ray diffraction at 1.95-Angstrom resolution using the multiwavelength anomalous diffraction method, with the zinc as the anomalous scatterer. The crystal structure shows that the core of the protein is a four-helix bundle, whereas the amino-terminal portion, which possibly interacts with the photosystem core, is not visible in the crystal. The distribution of positive and negative charges on the protein surface might explain the ability of PsbQ to increase the binding of Cl- and Ca2+ and make them available to PSII.