Structural Studies of Transcriptional Regulators

描述（由申请人提供）：我们研究的长期目标是了解基因调控的结构基础以及阻遏物、激活物和反终止子如何调控转录。多年来，我们一直专注于两个范例，大肠杆菌的乳糖操纵子和λ噬菌体的“遗传开关”。该基金最初资助了完整的lac阻遏物的三维结构测定，lac阻遏物与无偿诱导剂1-异丙基-D-硫代半乳糖苷（IPTG）结合，lac阻遏物与21个碱基对的对称操纵基因DNA复合。这三种结构为阻遏物在诱导和阻遏状态下提供了详细的结构模型，并为理解大量的生物化学和遗传信息提供了框架（刘易斯等人，1996年）。在这些结果的基础上，我们设计了新的实验并解决了结构，以更深入地探索这种蛋白质的功能。在这最后的授权期，我们还恢复了来自λ噬菌体的阻遏物的早期研究（Bell等人，2000），并提供了结构的见解，这种遗传开关的分子基础。在此资助期间，我们计划继续研究调节转录的蛋白质。我们研究的长期目标是了解基因调控的结构基础以及阻遏物、激活物和反终止子如何调控转录。

DESCRIPTION (provided by applicant): The long-range goal of our research is to understand the structural basis of gene regulation and how repressors, activators, and anti-terminators regulate transcription. Over the years, we have focused on the two paradigms, the lactose operon of E-coli and the "genetic switch" of bacteriophage lambda. This grant originally funded the three-dimensional structure determination of the intact lac repressor, the lac repressor bound to the gratuitous inducer 1-isopropyl-D-thiogalactoside (IPTG) and the lac repressor complexed with a 21 base-pair symmetric operator DNA. These three structures have provided a detailed structural model for repressor in the induced and the repressed states, and a framework for understanding a wealth of biochemical and genetic information (Lewis et al., 1996). Building upon these results, we designed new experiments and solved structures to probe more deeply the function of this protein. In this last granting period, we also resumed earlier studies of the repressor from phage lambda (Bell et al., 2000) and provided structural insight as to the molecular basis of this genetic switch. In this funding period, we plan to continue our studies on proteins that regulate transcription. The long-range goal of our research is to understand the structural basis of gene regulation and how repressors, activators, and anti-terminators regulate transcription.