CONFORMATIONS OF LIGHT-SENSITIVE PROTEINS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 结构生物学的一个主要目标是设计新的蛋白质并控制它们的功能，包括新的蛋白质到蛋白质的信号传递。蛋白质的模块化特性使这种工程成为可能，但连接各组成部分的机制尚未完全阐明。我们已经开发了一种简单的方法来连接两种蛋白质的功能，我们在这里展示了光触发的DNA结合。当光照时，这种光活性LOV结构域和细菌色氨酸抑制物的融合在光照时选择性地结合操纵子DNA。这项工作提出了重新编程细胞行为的新方法，如新陈代谢、形态和细胞死亡。 我们感兴趣的是研究大规模构象变化如何参与我们设计的蛋白质中信号的传播。最近的工作表明，一些，也许许多，LOV结构域对光的反应具有相当大的结构变化。我们的设计策略旨在利用这些变化，测量它们的大小以及它们与活动的关联是验证我们的结果的重要手段。我们在BioCAT进行的SAXS实验是这项工作的关键部分。在某些方面，他们证实了我们的期望，在另一些方面，他们挑战了我们的期望，并引导我们改进了我们的模型。PNAS接受的论文有待微小修改：设计的变构蛋白中的光激活DNA结合。德文·斯特里克兰、基思·莫法特和托宾·R·索斯尼克

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. A major aim in structural biology is to design new proteins and control their function, including novel protein-to-protein signalling. The modular nature of proteins makes such engineering possible, but mechanisms by which component parts can be connected have not been fully elucidated. We have developed a simple method to couple the functions of two proteins, which we demonstrate here with light-triggered DNA binding. When illuminated, this fusion of a photoactive LOV domain and bacterial trp repressor selectively binds operator DNA upon illumination. This work suggests new ways of reprogramming cellular behaviors such as metabolism, morphology, and cell death. We are interested in investigating how large scale conformational changes are involved in the propagation of signals in our designed protein. Recent work has shown that some, and perhaps many, LOV domains respond to light with rather large structural changes. Our design strategy aims to take advantage of these changes, and measuring their magnitude and how they correlate with activity is an important means of validating our results. The SAXS experiments we have undertaken at BioCAT have been a critical part of this work. In some respects they have confirmed our expectations and in others they have challenged them and led us to refine our model. Paper accepted at PNAS pending minor revision: Light-activated DNA binding in a designed allosteric protein. Devin Strickland, Keith Moffat, and Tobin R. Sosnick