Assembly and Function of Cyanobacterial Photosystem II

蓝藻光系统II的组装和功能

• 批准号: 0448567
• 负责人: Robert Burnap
• 金额: --
• 依托单位: Oklahoma State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0448567&HistoricalAwards=false
• 关键词: Assembly; Function; Cyanobacterial; Photosystem; II

Photosystem II (PSII) is a crucial but complex enzyme that forms the foundation of the photosynthetic machinery that supports all life on earth. This enzyme is responsible for using light energy to extract hydrogen from water. The overall process results in food for life on earth along with the removal of inorganic carbon from the earth's atmosphere and production of oxygen essential for earth's animals and other heterotrophic life forms. From an economic perspective, an understanding of this process is important if successful biomimetic devices are to be developed for such things as solar energy conversion to produce utilizable hydrogen or hydrides as an energy source to power future electric cars. Despite its importance, many aspects of the enzyme's mechanism remain poorly understood. Furthermore, photosystem II sustains very high rates of damage during its normal operation and is, thus, the 'Achilles Heel' of the plant. Many types of plant stress, including drought, result in the rapid and potentially lethal loss of photosystem II because of this damage. Plants must therefore constantly replace the damaged parts of photosystem II and this presents important biosynthetic challenges that are also still not understood.This research project is developing an understanding of the water-splitting mechanism and how the high rates of photosystem II repair are accomplished. The research takes the perspective that photosystem II is a molecular machine and that it is possible to understand how this machine operates by changing its parts using state-of-the-art genetic methods and probing the resultant changes in the machine's operation using a variety of informative biochemical and biophysical techniques. This research takes advantage of the recent crystallization and visualization of the molecular structure of the PSII 'machine'. It combines structure-based mutagenesis to study the assembly and function of the photosystem II complex in a model organism, Synechocystis PCC 6803. Specifically, this project will address hypotheses on the mechanism of photoactivation of photosystem II and will better define the protein factors participating in the repair cycle using microarray experiments.Broader Impacts: These extend beyond the immediate scientific area: 1) The proposed work will provide significant training opportunities for undergraduate students, graduate students, and postdoctoral fellows. 2) The project will have positive impact on the production of Synechocystis microarrays (distributed on a cost-return basis) and the workshops that the Oklahoma Microarray Core Facility conducts. These arrays serve teaching objectives and are being used to teach the principals of microarray production and applications in summer workshops serving the university and surrounding regions. 3) It will allow increased participation in the recently renewed Native Americans in Biological Sciences (NABS) program at Oklahoma State University.

光系统II（PSII）是一种重要但复杂的酶，它构成了支持地球上所有生命的光合机制的基础。这种酶负责利用光能从水中提取氢。整个过程导致地球上生命的食物沿着从地球大气中去除无机碳，并产生地球动物和其他异养生命形式所必需的氧气。从经济的角度来看，如果要开发成功的仿生装置，如太阳能转换，以产生可利用的氢气或氢气作为能源，为未来的电动汽车提供动力，那么对这一过程的理解是重要的。尽管它的重要性，酶的机制的许多方面仍然知之甚少。此外，光系统II在其正常运作期间维持非常高的损害率，因此是植物的“阿喀琉斯之踵”。许多类型的植物胁迫，包括干旱，导致光系统II的快速和潜在的致命损失，因为这种损害。因此，植物必须不断地替换光系统II受损的部分，这就提出了重要的生物合成挑战，但目前还不清楚。该研究项目正在发展对水分解机制的理解，以及光系统II的高修复率是如何实现的。这项研究的观点是，光系统II是一个分子机器，可以通过使用最先进的遗传方法改变其部件来了解这台机器的运作方式，并使用各种信息丰富的生物化学和生物物理技术来探测机器运作中的变化。这项研究利用了最近的结晶和可视化的PSII“机器”的分子结构。它结合了基于结构的诱变研究的组装和功能的光系统II复合体的模式生物，集胞藻PCC 6803。具体而言，本项目将解决光系统II的光活化机制的假说，并将使用微阵列实验更好地确定参与修复周期的蛋白质因子。更广泛的影响：这些扩展超出了直接的科学领域：1）拟议的工作将为本科生，研究生和博士后研究员提供重要的培训机会。2)该项目将对集胞藻微阵列的生产（以成本回报为基础分发）和俄克拉荷马州微阵列核心设施举办的研讨会产生积极影响。这些阵列服务于教学目标，并被用于在为大学和周边地区服务的夏季研讨会上教授微阵列生产和应用的负责人。3)它将允许更多的人参与最近更新的俄克拉荷马州州立大学生物科学（NABS）计划。