MUTANTS OF RHODOBACTER-SPHAEROIDES LACKING ONE OR MORE PIGMENT PROTEIN COMPLEXES AND COMPLEMENTATION WITH REACTION-CENTER, LH1, AND LH2 GENES
MUTANTS OF RHODOBACTER-SPHAEROIDES LACKING ONE OR MORE PIGMENT PROTEIN COMPLEXES AND COMPLEMENTATION WITH REACTION-CENTER, LH1, AND LH2 GENES
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DOI：
10.1111/j.1365-2958.1992.tb01556.x
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发表时间：
1992-05-01
影响因子：
3.6
通讯作者：
HUNTER, CN
中科院分区：
文献类型：
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作者：
JONES, MR;FOWLER, GJS;HUNTER, CN
球形红细菌的光合机构由三种类型的色素蛋白复合物组成：光化学反应中心及其伴随的LH 1和LH 2捕光复合物。为了增强编码这些复合物的基因中现有的缺失/插入突变体，我们构建了另外两种突变体，其中之一是一种新的双突变体，它缺乏所有三种类型的复合物。我们还构建了用于表达LH 1、LH 2或反应中心基因的载体。由此产生的系统允许每个色素-蛋白质复合物作为完整光系统的一部分或作为细胞中的唯一复合物进行研究。通过这种方式，我们证明了反应中心可以独立于R中的任何一个捕光复合物进行组装。sphaeroides此外，在类胡萝卜素生物合成中表现出自发突变的缺失/插入突变体的衍生物的分离提供了一种途径，用于检查类胡萝卜素在光合装置组装中的作用。我们表明，LH 1复合物组装的类胡萝卜素背景无关，和类胡萝卜素的类型存在修改的LH 1细菌叶绿素的吸光度。
The photosynthetic apparatus of Rhodobacter sphaeroides is comprised of three types of pigment-protein complex: the photochemical reaction centre and its attendant LH1 and LH2 light-harvesting complexes. To augment existing deletion/insertion mutants in the genes coding for these complexes we have constructed two further mutants, one of which is a novel double mutant which is devoid of all three types of complex. We have also constructed vectors for the expression of either LH1, LH2 or reaction-centre genes. The resulting system allows each pigment-protein complex to be studied either as part of an intact photosystem or as the sole complex in the cell. In this way we have demonstrated that reaction centres can assemble independently of either light-harvesting complex in R. sphaeroides. In addition, the isolation of derivatives of the deletion/insertion mutants exhibiting spontaneous mutations in carotenoid biosynthesis provides an avenue for examining the role of carotenoids in the assembly of the photosynthetic apparatus. We show that the LH1 complex is assembled regardless of the carotenoid background, and that the type of carotenoid present modifies the absorbance of the LH1 bacteriochlorophylls.