Liu Haijun, Frankel Laurie K, Bricker Terry M
Department of Biological Sciences, Division of Biochemistry and Molecular Biology, Louisiana State University, Baton Rouge, LA 70803, USA.
Arch Biochem Biophys. 2009 Sep;489(1-2):34-40. doi: 10.1016/j.abb.2009.07.014. Epub 2009 Jul 28.
In this communication we have characterized an Arabidopsis thaliana mutant which lacks the PsbR protein of Photosystem II and complemented its phenotype by introduction and expression of a C-terminally His(6)-tagged PsbR protein. Absence of the PsbR protein leads to decreased levels of the PsbP, PsbQ and D2 proteins associated with Photosystem II membranes. Functional defects in the mutant were localized principally to the reducing-side of the photosystem and included slowing of electron transfer from Q(A)(-) to Q(B). These defects were almost fully corrected in transgenic plants containing the C-terminally His(6)-tagged PsbR protein. We hypothesize that the functional defects observed in the mutant were due to defective assembly and/or binding of the PsbP and PsbQ components to Photosystem II in the absence of the PsbR protein.
在本通讯中，我们鉴定了一种拟南芥突变体，该突变体缺乏光系统II的PsbR蛋白，并通过引入和表达C末端带有His(6)标签的PsbR蛋白来互补其表型。PsbR蛋白的缺失导致与光系统II膜相关的PsbP、PsbQ和D2蛋白水平降低。突变体中的功能缺陷主要定位于光系统的还原侧，包括从Q(A)(-)到Q(B)的电子传递减慢。在含有C末端His(6)标签的PsbR蛋白的转基因植物中，这些缺陷几乎得到了完全纠正。我们推测，在突变体中观察到的功能缺陷是由于在没有PsbR蛋白的情况下，PsbP和PsbQ组件与光系统II的组装和/或结合存在缺陷。
