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帮助细胞有机体检测并响应其光环境。 其中最有影响力的是光敏色素超家族，它是原核生物和真核生物中存在的一大类多样化的光感受器。 它们是光致变色颜料，使用线性四吡咯或胆碱生色团来感应红光和远红光。 光敏色素型光感受器首先在高等植物中被发现，因为它们能够引发对农业生产力至关重要的大量光响应。 最近，它们也被证明存在于各种微生物中，包括蓝细菌、真细菌、真菌和粘菌。 该研究项目的目标是通过深入分析细菌光敏色素亚家族（最近在细菌和真菌中发现的相关光敏色素的集合），进一步了解光敏色素的功能。这些细菌光敏色素为研究简单的遗传易处理生物体中的光敏色素提供了一个有吸引力的机会，这些生物体几乎没有光感受器，缺乏光合作用的复杂性，并且能够产生结构分析所需的大量均匀且稳定的色素。 该项目具体将尝试：（1）通过细菌光敏色素晶体的 X 射线衍射分析解决光敏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如何在微生物中发挥作用。 这项研究的完成将首次详细介绍光敏色素如何发挥作用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高等植物如何通过这种独特的光感受器类型感知其光环境，从而可能具有重要的农业意义。 此外，该研究还将通过学院/大学合作安排加强科学基础设施，以培训现代分子技术的博士后、研究生和本科生。