NMR STUDIES OF THE MECHANISMS OF ACTION OF TRP REPRESSOR

拟议项目的目标是实现一个详细和 精确理解遗传调控的分子机制， 在这一机制运作的具体变化的水平上 是可以预测和设计的。预测和控制的能力 对遗传调节机制功能的修改将具有 对治疗遗传病的能力和 将这些机制作为合理药物设计的目标，但现有的 到目前为止，知识还不足以实现这些目标。 选择来自大肠杆菌的trp阻遏子作为详细的模型系统 学习，因为它是最小和最简单的完整之一 目前可用的监管系统。从已知的结构开始 抑制蛋白，在有或没有激活剂L色氨酸的情况下， 而对于dna-抑制子-L-Trp三元复合体，有可能 系统地研究每个结构元素(氨基)的作用 酸残基)在(1)与L-色氨酸配体保持特定的接触 以及(2)与操纵者DNA和(3)传递信号调节 结合部位之间的DNA结合。这将通过以下方式实现 研究已知可改变基因的点突变和多重突变 系统的构象和动力学。非常有希望的初步结果 已经通过一些突变体获得了，提供了明确的 未来研究的方向。研究结果的相关性应该允许 对信令代码的理解和调节器的设计 仪器。

The objective of the proposed project is to achieve a detailed and precise understanding of the molecular mechanism of genetic regulation, at a level at which specific changes in the operation of this mechanism could be predicted and engineered. The ability to predict and control modifications to the function of genetic regulatory mechanisms will have far reaching consequences to the ability to treat genetic diseases and to use the mechanisms as targets for rational drug design, but existing knowledge is as yet insufficient to reach these goals. The trp-repressor from E. coli was chosen as a model system for detailed study, because it is one of the smallest and simplest complete regulatory systems available today. Starting with the known structures of the repressor protein, with and without the activator L-tryptophan, and of the ternary DNA-repressor-L-trp complex, it is possible to systematically investigate the role of each structural element (amino acid residue) in (1) maintaining specific contacts with the L-trp ligand and (2) with the operator DNA and (3) transmitting the signal regulating DNA binding between the binding sites. This will be achieved by studying point and multiple mutations which are known to alter the conformation and dynamics of the system. Very promising initial results have already been obtained with some of the mutants, providing clear directions for future studies. Correlation of the findings should allow an understanding of the signaling code and the design of the regulatory apparatus.