STRUCTURAL ANALYSIS OF THE MNT-DNA COMPLEX

基因调控蛋白如阻遏物和激活物参与其中 在各种基本的细胞过程中。这些蛋白质结合 特定的DNA序列，并调节多种 必需基因真正了解这些蛋白质的结构 在原子分辨率下，将允许蛋白质的合理设计， 可以与细胞或病毒DNA中的特定DNA序列结合。在 在本提案中描述的研究中，将使用X射线晶体学 确定噬菌体P22 Mnt的三维结构 阻遏物和几种Arc/Mnt杂合蛋白结合到mnt操纵基因DNA。 Mnt和Arc/Mnt杂合体的N-末端DNA结合结构域将是 克隆、表达和纯化。将生长蛋白质-DNA共晶体 并将确定复合物的三维结构， 原子分辨率从这些研究中获得的结构信息 无疑会加深我们对不同运营商 序列被识别，以及单个残基变化如何导致 蛋白质的DNA结合特异性的急剧变化。这 理解将增强我们用新DNA设计蛋白质的能力 用于医学和研究应用的结合特异性。

Gene regulatory proteins such as repressors and activators are involved in a variety of fundamental cellular processes. These proteins bind specific DNA sequences and regulate the expression of a multitude of essential genes. A true understanding of the structure of these proteins at atomic resolution would allow the rational design of proteins that could bind to specific DNA sequences in cellular or viral DNA. In research described in this proposal, x-ray crystallography will be used to determine the three dimensional structures of bacteriophage P22 Mnt repressor and several Arc/Mnt hybrid proteins bound to mnt operator DNA. The N-terminal DNA binding domains of Mnt and the Arc/Mnt hybrids will be cloned, expressed, and purified. Protein-DNA Co-crystals will be grown and the three-dimensional structure of the complexes will be determine at atomic resolution. The structural information gained from these studies will undoubtedly enhance our understanding of how distinct operator sequences are recognized and how a single residue change can result in drastic changes in DNA binding specificity of a protein. This understanding will augment our ability to design proteins with novel DNA binding specificities for use in medicinal and research applications.