CRYSTALLOGRAPHIC STUDY OF PHOTOSYNTHETIC REACTION CENTER

这个项目的目的是确定详细的分子结构。 来自光合作用细菌的光合作用反应中心 球状红杆菌对该蛋白单晶的研究 通过X-射线衍射法测定了络合物的含量。反应中心是内在的 执行光合作用初始步骤的膜蛋白 指控分离。RB。球状核反应中心(MR等于 约100,000)包含三个蛋白质亚基，四个 细菌叶绿素，两个细菌酚，两个泛醌，一个 类胡萝卜素和一个非血红素铁。我们将继续完善 R-26反应中心的结构，并将其与其他 反应中心结构。我们将开始结构确定在 通过特定部位改变的反应中心 诱变。我们计划通过使用常规方法来确定结构 结晶学方法。 RB。球藻反应中心服务模式系统研究 跨膜电子传递是如何与产物相耦合的 膜电位。这个反应中心已经得到了广泛的研究 通过光谱和生化方法。反应中心 络合物在晶体中是功能性的；因此，我们有一个独特的 将光谱结果与三维空间关联的机会 建筑群的结构。 这一研究将有助于对汉语句式结构的理解 膜蛋白。RB。斯帕罗里德反应中心只是 少数几种膜蛋白的可用性为高度有序 晶体使详细结构的测定成为可能。这个 ITS氨基酸序列与三维结构的相关性 结构将增加膜蛋白的数据库，从而 显著增强了对这些类型的结构预测的努力 蛋白质。

The aim of this project is to determine the detailed molecular structure of the photosynthetic reaction center from the photosynthetic bacterium Rhodobacter sphaeroides by studying single crystals of this protein complex through x-ray diffraction. Reaction centers are intrinsic membrane proteins that carry out the initial steps in photosynthetic charge separations. The Rb. sphaeroides reaction center (Mr equals approximately 100,000) contains three protein subunits, four bacteriochlorophylls, two bacteriophenophytins, two ubiquinones, one carotenoid, and one nonheme iron. We will continue to refine the structure of the reaction center from R-26 and will compare it to other reaction center structures. We will start structure determinations on reaction centers that have been altered through site-specific mutagenesis. We plan to determine structures by using conventional crystallographic methods. The Rb. sphaeroides reaction center serves a model system to study how transmembrane electron transport is coupled to the production of membrane potential. This reaction center has been studied extensively through both spectroscopic and biochemical methods. The reaction center complex is functional in the crystal; therefore, we have a unique opportunity to correlate spectroscopic results with the three-dimensional structure of the complex. This study will contribute to the understanding of the structure of membrane proteins. The Rb. sphaeroides reaction center is only one of a few membrane proteins for which the availability of highly ordered crystals makes the determination of detailed structure possible. The correlation of its amino acid sequence with the three-dimensional structure will increase the database for membrane proteins, thereby markedly enhancing structure prediction efforts for these types of proteins.