GENETICS OF FLAVIN DEHYDROGENASE-MEMBRANE INTERACTIONS

本研究的目的是确定黄素分解酶 与鼠伤寒沙门氏菌的膜相互作用。 这项工作将 重点关注两个主要议题： 1. put操纵子的调控。 put操纵子具有独特的控制能力 该机制由putA基因产物介导。 当外源 当脯氨酸可用时，PutA蛋白结合到膜上， 作为黄素脱氢酶的功能;但在缺乏脯氨酸的情况下， 在细胞质中积累，在那里它作为自体阻遏物。 确定脯氨酸脱氢酶如何控制其自身的表达， 帮助我们了解其他膜结合调节蛋白的工作原理。 此外，putA突变的调节特性提供了一种 膜相互作用突变体的遗传选择。 2. 黄素氧化酶-膜相互作用。 黄素氧化酶 必须与膜相关联，以便与膜适当地相互作用。 电子传递链。 然而，尚不清楚它们如何相互作用 与细胞膜或电子传递链的什么成分， 直接互动。 PutA基因互作的遗传学研究 蛋白质与膜的结合提供了一个模型系统， 蛋白质在体内与膜相互作用。 蛋白质-蛋白质和 膜结合所需的蛋白质-脂质相互作用可以是 通过分离防止PutA蛋白从 与膜结合。 这些基因和生化分析 突变体将表明什么样的相互作用之间需要 黄素化酶和膜电子传递链。 等 突变体应该提供洞察一般的生物学问题， 外周膜蛋白与膜相互作用。

The objective of this study is to determine how flavin dehydrogenases interact with the membrane in Salmonella typhimurium. This work will focus on two main topics: 1. Regulation of the put operon. The put operon has a unique control mechanism that is mediated by the putA gene product. When exogenous proline is available, the PutA protein binds to the membrane where it functions as a flavin dehydrogenase; but in the absence of proline, it accumulates in the cytoplasm where it acts as an autogenous repressor. Determining how proline dehydrogenase controls its own expression may help us understand how other membrane-bound regulatory proteins work. In addition, the regulatory properties of putA mutations provide a genetic selection for membrane interaction mutants. 2. Flavin dehydrogenase-membrane interactions. Flavin dehydrogenases must associate with the membrane in order to interact properly with the electron transport chain. However, it is not known how they interact with the membrane or what components of the electron transport chain they interact with directly. Genetic studies on the interaction of PutA protein with the membrane provides a model system for understanding how proteins interact with membranes in vivo. The protein-protein and protein-lipid interactions required for membrane association can be determined by isolation of mutants that prevent the PutA protein from binding to the membrane. Genetic and biochemical analysis of these mutants will indicate what kinds of interactions are required between flavin dehydrogenases and the membrane electron transport chain. Such mutants should provide insight into the general biological problem of how peripheral membrane proteins interact with the membrane.