Structure and Function of Supercomplexes of Photosystem I with its Peripheral Antenna Systems in Green Algae and Cyanobacteria

绿藻和蓝藻中光系统 I 及其外围天线系统超级复合体的结构和功能

• 批准号: 0417142
• 负责人: Petra Fromme
• 金额: $ 164.8万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-12-01 至 2011-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0417142&HistoricalAwards=false
• 关键词: Structure; Function; Supercomplexes; Photosystem; its

Photosynthesis is the main process on Earth that converts light energy from the sun into chemical energy accessible for living organisms. The products of photosynthesis ultimately provide all higher life on earth with energy and produce all oxygen in the atmosphere. The aim of this project is to unravel the structure and function of the large molecular solar energy converter Photosystem I (PSI) and to determine the interaction of its peripheral antenna systems in eukaryotes (plants and green algae) and prokaryotes (cyanobacteria). The photosystem I complex consists of 12-14 proteins to which more than 120 cofactors (chlorophylls and carotenoids) are bound. Furthermore, photosystem I is dynamically coupled to additional peripheral antenna systems to further increase the efficiency of light capturing. The project aims to unravel the structure and function of both the plant-type photosystem I in a supercomplex with the light harvesting complex I and the cyanobacterial photosystem I in its supercomplex with 18 IsiA proteins. The overall goal of the project is the determination of the structure of both photosystem I-antenna supercomplexes in plant-type and cyanobacterial photosystem I. The experimental setup includes crystallization and structure-determination by X-ray structure analysis, the design of structurally and functionally improved complexes by mutagenesis and functional investigations by time-resolved spectroscopy. The project will lead to detailed insights into the structural organization of the photosynthetic system in prokaryotes and eukaryotes and will unravel the functional coupling of the external antenna complexes to the core units of photosynthesis. Furthermore the project will provide new insights into protein assembly during the formation of large supercomplexes of membrane proteins. Broader ImpactsKnowledge of the atomic details of the structure of giant Photosystem I supercomplexes will boost our understanding of the mechanisms of basic processes of bio-solar energy conversion. Moreover, this will help to elucidate structure-functional relationships between the photosynthetic reaction centers and their peripheral antennas in the supercomplexes that determine a higher efficiency and flexibility of the energy conversion in the bio-solar systems than in man-made systems. The project will thereby provide broad impacts for the development of new concepts for solar energy converters that mimic nature. Furthermore, fundamental understanding of the photosynthetic processes could lead to the development of plants with enhanced photosynthetic ability and increased tolerance to many kinds of environmental stress. One of the aims of the project is to use gained knowledge for boosting students' interest in revealing the secrets of natural energy conversion and enhancing their motivation in studying science. The project will also give an opportunity to inform the public on recent discoveries in this exciting area.

光合作用是地球上的主要过程，它将来自太阳的光能转化为生物体可获得的化学能。光合作用的产物最终为地球上所有高等生物提供能量，并产生大气中所有的氧气。本项目的目的是揭示大分子太阳能转换器光系统I（PSI）的结构和功能，并确定其外周天线系统在真核生物（植物和绿色藻类）和原核生物（蓝藻）中的相互作用。光系统I复合物由12-14种蛋白质组成，其上结合有超过120种辅因子（叶绿素和类胡萝卜素）。此外，光系统I动态耦合到额外的外围天线系统，以进一步提高光捕获的效率。该项目旨在揭示植物型光系统I与捕光复合物I的超复合物和蓝藻光系统I与18种IsiA蛋白的超复合物的结构和功能。该项目的总体目标是确定植物型和蓝藻光系统I中光系统I-天线超复合物的结构。实验设置包括结晶和结构测定的X-射线结构分析，设计的结构和功能改进的复合物的诱变和功能调查的时间分辨光谱。该项目将导致对原核生物和真核生物光合系统结构组织的详细了解，并将解开外部天线复合物与光合作用核心单元的功能耦合。此外，该项目将提供新的见解蛋白质组装过程中形成的大型超复合物的膜蛋白。更广泛的影响巨大的光系统I超复合物结构的原子细节的知识将促进我们对生物太阳能转换的基本过程的机制的理解。此外，这将有助于阐明超复合体中光合反应中心及其外围天线之间的结构-功能关系，这些关系决定了生物太阳能系统中能量转换的效率和灵活性高于人造系统。因此，该项目将为模仿自然的太阳能转换器的新概念的开发提供广泛的影响。此外，对光合作用过程的基本理解可以导致植物的发展，提高光合能力和对多种环境胁迫的耐受性。该项目的目的之一是利用获得的知识来提高学生揭示自然能源转换秘密的兴趣，并提高他们学习科学的动力。该项目还将提供一个机会，让公众了解这一令人兴奋的领域的最新发现。