STRUCTURAL STUDIES OF THE REACTION CENTER FROM RHODOBACTER SPHAEROIDES

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。光合作用反应中心(RC)是一种完整的膜蛋白-色素复合体，它执行从细菌-叶绿素二聚体(D)到两个苯二酚分子QA和QB的光诱导电子转移。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)。对参与电荷分离的中间体，包括D+QA-、D+QB-和双自由基中间态DQA-QB-的结构进行提高分辨率的测定。

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. Photosynthetic reaction centers (RC) are integral membrane protein-pigment complexes that perform light induced electron transfer from a bacteriochlorophyll dimer (D) 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 the RC. 3). Determination of the structures at an enhanced resolution of intermediates that are involved in the charge separation, including D+QA-, D+QB-, and the biradical intermediate state DQA-QB-.