A Novel Fur Protein in Bradyrhizobium japonicum

铁是几乎所有生物体的必需营养素。然而，高浓度的铁也会对细胞产生毒性，因此生物体必须保持这种营养素的适当平衡。该项目旨在了解细胞如何感知环境中铁的可用性并调节其在细胞中的浓度。本研究的重点是大豆慢生根瘤菌（Bradyrhizobium japonicum）的铁稳态，大豆慢生根瘤菌是一种重要的农业细菌，也是研究基因表达代谢调控的良好模型。大多数细菌都含有一种名为Fur的蛋白质，它可以感知并结合铁，并调节与铁代谢有关的基因。Fur功能的模型是与铁结合赋予蛋白质通过识别特定靶DNA序列来负调控基因的能力。然而，来自B. Japonicum（BjFur）具有独特的性质，表明新的细胞作用。特别地，BjFur结合到被其他Fur蛋白识别的DNA序列，但也特异性地结合到不被来自其他细菌的Fur识别的DNA元件。此外，最近的证据有力地表明，BjFur可以在铁限制下发挥作用，这在其他生物体中尚未报道。这些观察结果导致的假设，毛皮是功能更多样化的活动和作用比一般假设。将进行实验，解决B的新功能。japonicum Fur蛋白。这项工作将包括培训研究生和本科生，并将大力鼓励妇女和代表性不足的少数民族受训人员参与。

Iron is an essential nutrient in almost all living organisms. However, iron can also be toxic to cells in high concentrations, and therefore organisms must maintain the proper balance of this nutrient. This project aims to understand how cells sense the availability of iron in the environment and regulate its concentration in cells. The research focuses on iron homeostasis in Bradyrhizobium japonicum, a bacterium important to agriculture and a good model for studying the metabolic regulation of gene expression. Most bacteria contain a protein called Fur, which senses and binds to iron, and regulates genes involved in iron metabolism. The model for Fur function is that binding to iron confers on the protein the ability to negatively regulate genes by recognizing specific target DNA sequences. However, the Fur protein from B. japonicum (BjFur) has unique properties that indicate novel cellular roles. In particular, BjFur binds to DNA sequences recognized by other Fur proteins, but also binds specifically to a DNA element not recognized by Fur from other bacteria. In addition, recent evidence strongly suggests that BjFur can function under iron limitation, which has not been reported in other organisms. These observations lead to the hypothesis that Fur is functionally more diverse in its activities and roles than is generally assumed. Experiments will be carried out that address the novel features of the B. japonicum Fur protein. This work will involve the training of graduate and undergraduate students, and will strongly encourage participation by women and underrepresented minority trainees.