STRUCTURAL STUDIES OF THE PHOTOSYNTHETIC REACTION CENTER FROM RHODOBACTER SPHAER

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 反应中心(RC)是执行光诱导的电子转移反应的完整的膜蛋白，这是将阳光转化为化学能的第一步。电子从细菌叶绿素二聚体(D)的激发态通过几个中间受体分子转移到两个苯二酚分子QA和QB。RC与另一个含有色素的完整膜蛋白形成复合体，称为捕光复合体(LH1)，其主要功能是收集光并将这种能量转移到RC并光氧化D。此外，一个14千道尔顿的水溶性细胞色素c2瞬时与RC结合并重新还原D。我们在SSRL进行的工作将集中在RC的三个结构功能方面：1)。与其他蛋白质结合的RC的结构测定：a)。Rc和捕光蛋白(LH1)，以及b)。影响rc与cytc2结合和电子转移的突变体。2)。确定在RC中影响质子和电子转移事件的突变体的结构。3)。测定参与电荷分离的中间体的结构。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The Reaction Center (RC) is the integral membrane protein that performs the light induced electron transfer reactions that are the first steps in conversion of sunlight into chemical energy. Electron transfer occurs from the excited state of a bacteriochlorophyll dimer (D) through several intermediate acceptor molecules to two quinone molecules, QA and QB. The RC forms a complex with another pigment-containing integral membrane protein called the light-harvesting complex (LH1) whose primary function is to gather light and transfer this energy to the RC and photo-oxidize D. In addition, a 14-kilodalton water soluble-cytochrome c2 transiently binds to the RC and re-reduces D. Our ongoing work at SSRL will focus on three structure-function aspects of the RC: 1). Determination of the structure of the RC complexed with other proteins: a). RC and light harvesting protein (LH1), and b). Mutants that affect the binding and electron transfer between RC with cyt c2. 2). Determination of the structures of mutants that affect proton and electron transfer events in RC. 3). Determination of the structures of intermediates that are involved in the charge separation.