Structural and Functional Analysis of the Bacteriophytochrome Photoreceptors: Models for the Phytochrome Superfamily

细菌光敏色素光感受器的结构和功能分析：光敏色素超家族的模型

• 批准号: 0424062
• 负责人: Richard Vierstra
• 金额: $ 41.4万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2008-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0424062&HistoricalAwards=false
• 关键词: Structural; Functional; Analysis; Bacteriophytochrome; Photoreceptors

A complex array of photoreceptors help cellular organisms detect and respond to their light environment. One of the most influential is the phytochrome superfamily, a large and diverse group of photoreceptors present in both prokayotes and eukaryotes. They are photochromic pigments that use a linear tetrapyrrole or bilin chromophore to sense red and far-red light. Phytochrome-type photoreceptors were first discovered in higher plants by their ability to initiate numerous photoresponses critical for agricultural productivity. More recently, they have been shown to also exist in various microorganisms, including cyanobacteria, eubacteria, fungi and slime molds. The goal of this research project is to further understand how phytochromes function through an in-depth analysis of the bacteriophytochrome subfamily, a collection of related phytochromes that were recently discovered in bacteria and fungi. These bacteriophytochromes offer an attractive opportunity to study phytochromes in simple genetically-tractable organisms that possess few photoreceptors and lack the complications of photosynthesis, and the ability to generate ample quantities of homogeneous and stable pigment needed for structural analyses. This project specifically will attempt to: (1) solve the first three-dimensional structure of a phytochrome-type photoreceptor by X-ray diffraction analyses of bacteriophytochrome crystals, and (2) exploit various genomic methods to define how these photoreceptors function in microorganisms. Completion of this research will provide the first detailed picture of how phytochromes work mechanistically and affect the behavior of microorganisms. More broadly, this work will ultimately help elucidate how higher plants sense their light environment via this unique photoreceptor type and thus could have important agricultural implications. In addition, the research will enhance scientific infrastructure via a cooperative college/university arrangement for the training of postdoctoral, graduate and undergraduate students in modern molecular techniques.

一系列复杂的光感受器有助于细胞生物检测并响应其光环境。 最有影响力的人之一是植物色素超家族，这是原始人和真核生物中存在的大型且多样的感光体。 它们是使用线性四吡咯或Bilin发色团感知红色和远红色光的光致变色颜料。 植物色素型光感受器首先是在较高植物中发现的，其能够启动对农业生产力至关重要的许多光呼应的能力。 最近，它们也显示出在各种微生物中也存在，包括蓝细菌，花生菌，真菌和粘液霉菌。 该研究项目的目的是进一步了解植物色素如何通过对细菌性色素亚家族的深入分析，这是最近在细菌和真菌中发现的相关植物色素的集合。这些细菌性卵黄具有一个有吸引力的机会，可以在简单的遗传学生物中研究植物色素，这些生物具有很少的光感受器，并且缺乏光合作用的并发症，并且能够产生足够数量的结构性分析所需的均质和稳定的色素。 该项目将特别尝试：（1）通过X射线衍射分析植物色素晶体晶体的植物色素型光感受器的第一个三维结构，以及（2）利用各种基因组方法来定义这些光感受器在微生物中的作用。 这项研究的完成将提供第一个详细的图片，说明植物色素如何机械地工作并影响微生物的行为。 更广泛地说，这项工作最终将有助于阐明较高的植物如何通过这种独特的光感受器类型感知其光环境，从而具有重要的农业意义。 此外，该研究将通过合作学院/大学安排来增强科学基础设施，以培训现代分子技术的博士后，研究生和本科生。