Type-1 Photochemical Reaction Centers: Paradigm, Variations, and Applications

智力价值这个项目提供了一个综合的、全面的研究和培训计划，通过关注自然光合作用研究的重要基础和应用方面，广泛地关注环境和能源主题。这项研究将在合作伙伴唐纳德·A·布莱恩特和约翰·H·戈尔贝克的实验室联合进行，他们在自然光合作用方面的合作研究已有20多年的历史。该项目的中心“范例”源于对蓝藻1型光化学反应中心(RCS)结构和功能细节的研究。这项工作对环境具有重要意义的潜在影响包括：新发现的耐氧同源二聚体1RC的生化特征(目标1)；确定嗜铁蓝藻中编码光系统I(PS I)亚单位的基因的多个拷贝的功能、环境和潜在的进化相关性(目标2)；在蓝藻聚球藻属的模型中使用条件控制基因表达来研究蓝藻的类囊体膜和PS I的生物发生。PCC 7002(目标3)。就对太阳能的重要性而言，该项目的潜在影响涉及描述PS I中初级电荷分离的动力学(目标4)。从本文建议的研究中获得的知识的应用，以及在NSF支持的20多年的研究中由Co-Pis进行的知识的应用，明显体现在拟议的PS I分子导线结构的开发中，该结构用作光驱动的电子注入装置，以研究氧化还原活性酶中的质子耦合电子转移反应的机制(目标5)。这项研究计划的成功完成将大大增加对第一类RCS中一次电荷分离机理的了解，并将为未来开发执行太阳能捕获和转换的设备提供具有启发性的新见解。有很好的理由相信，有可能识别出一种通过生物合成的无机催化剂，它将模拟费托反应，但在298K和1bar下产生C-C键。Broader Impact这个研究计划旨在提供出色的培训机会，使Co-PIs能够在微生物生态学、生理学、遗传学、基因组学、生物化学和生物物理学等主题上共同指导研究生和本科生。将这些研究项目合并为一个项目的原因之一是为学生提供更广泛、更好的综合培训，从而使他们能够更全球化地思考与能源和环境有关的问题。这项提案的目的也是以这种方式组织起来的，以说明这些项目如何从最初以微生物生态学和环境为基础的研究，到以生物化学和生物物理学为坚实基础的研究，在逻辑上取得进展。基于他们在自然光合作用、光收集和太阳能转换过程中的广泛研究兴趣和前景，CoPIs将帮助培养下一代学术和工业科学家，该领域对我们社会的战略利益和长期经济繁荣日益重要。合作伙伴将继续广泛参与科学领域的外展和协同关系。这一努力的重要方面包括承诺让专门或主要是本科院校的教职员工和学生参与我们的研究计划。合作伙伴致力于继续其目前对科学方面代表性不足的少数群体的学生的培训。最后，计划在高中和小学两级开展外联和教育活动。

Intellectual Merit This project presents an integrated, comprehensive research and training program that focuses broadly on the topics of environment and energy - through its focus on important fundamental and applied aspects of research on natural photosynthesis. The research will be conducted jointly in the laboratories of Co-PIs Donald A. Bryant and John H. Golbeck, who have collaborated on research in natural photosynthesis for more than twenty years. The central "paradigm" of this project derives from research to understand the structural and functional details of type-1 photochemical reaction center (RCs) of Cyanobacteria. The potential impact of the work in terms of significance to the environment includes the biochemical characterization a newly discovered, oxygen-tolerant homodimeric Type-1 RC (Aim 1); determining the functional, environmental, and potentially evolutionary relevance of multiple copies of genes encoding Photosystem I (PS I) subunits in an iron-loving cyanobacterium, (Aim 2); conducting studies of cyanobacterial thylakoid membrane and PS I biogenesis using conditionally controlled gene expression in the model cyanobacterium Synechococcus sp. PCC 7002 (Aim 3). The potential impact of the project in terms of significance to solar energy involves characterizing the dynamics of primary charge separation in PS I (Aim 4). The application of knowledge gained from the studies proposed herein, as well as those conducted during more than 20 years of NSF-supported research by the Co-PIs, is evident in the proposed development of a PS I-molecular wire construct to serve as a light-driven, electron-injection device to study the mechanisms of proton-coupled, electron transfer reactions in redox-active enzymes (Aim 5). The successful completion of this research program will significantly increase an understanding of the mechanism of primary charge separation in type-1 RCs and should also provide instructive new insights for the future development of devices to perform solar energy capture and conversion. There are excellent reasons to believe that it may be possible to identify an inorganic catalyst that is synthesized biologically and that would mimic the Fischer-Tropsch reaction but generate C-C bonds at 298 K and 1 bar.Broader Impacts This research program is designed to present outstanding training opportunities that will allow the Co-PIs to co-mentor graduate and undergraduate students in topics that include microbial ecology, physiology, genetics, genomics, biochemistry, and biophysics. One reason for merging these research programs into a single program was to provide broader, better integrated training to students, whom will thus be able to think more globally about issues concerning energy and the environment. The aims of this proposal were similarly organized in such a way to illustrate how these projects progress logically from studies with their origins in microbial ecology and the environment to those that are firmly based in biochemistry and biophysics. Based upon their combined, broad research interests and perspectives in natural photosynthesis, light harvesting, and solar energy conversion processes, the Co-PIs will help to train the next generation of academic and industrial scientists in a field that is growing in importance to the strategic interests and long-term economic prosperity of our society. The Co-PIs will continue their extensive involvement in outreach and synergistic relationships in science. Important aspects of this effort include a commitment to involving both faculty and students at exclusively or predominantly undergraduate institutions in our research program. The Co-PIs are committed to continuing their current training of students who are members of underrepresented minorities in science. Finally, outreach and educational activities at the high school and grade school levels are planned.