A SAXS STUDY OF THE LIGHT-SENSING REACTION OF PLANT AND BACTERIAL PHYTOCHROMES

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。蛋白质光感受器允许生物有机体感知、处理和传输环境光中包含的信息。光照强度是否足以支持生长？现在是一天/一年中的什么时候？邻近的生物是否阻挡了阳光的照射？植物和细菌利用光敏色素家族中的光感受器来寻找所有这些问题的答案。我们想了解光敏色素生物学功能的分子机制。光敏色素是一种大的水溶性多结构域光感受器。光敏色素的光活化已被证明能引起大规模的构象变化。大多数光敏色素结构域的蛋白质折叠是已知的，因此我们可以通过同源性建模来建立这些结构域的分子模型。本研究的目的是利用小角度x射线散射数据将单个区域的分子模型组装成全长光敏色素的模型。此外，我们还想确定这种结构域的排列是如何随着光激活而变化的。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Protein photoreceptors allow biological organisms to sense, process and transmit the information contained in ambient light. Are light intensities sufficient to support growth? What time of day / year is it? Is a neighboring organism blocking access to sunlight? Plants and bacteria use photoreceptors from the phytochrome family to find the answer to all of these questions. We want to understand the molecular mechanism underlying phytochromes¿¿ biological function. Phytochromes are large, water-soluble multi-domain photoreceptors. Light activation of phytochromes has been shown to induce large-scale conformational changes. The protein fold for most phytochrome domains is known, thus allowing us to built molecular model of these domains by homology modeling. The goal of the proposed research is to use Small Angle X-ray scattering data to assemble the molecular models of individual domains into a model for the full-length phytochrome. In addition we would want to determine how this domain arrangement changes as a result of light-activation.