ETS TRANSCRIPTION FACTOR--THE PU.1-DNA COMPLEX

转录因子结合到特定的DNA序列并调节 重要的代谢功能，如细胞生长、发育和 差异化。人们对了解其功能非常感兴趣 这些调节蛋白，特别是当它们的作用与 致癌作用。PU.1转录因子是Ets基因的一个成员 与红系白血病发生有关的家族 和乳腺癌的肿瘤发生有关。ETS蛋白具有保守的 85个氨基酸组成的区域(Ets结构域)，与DNA结合并识别 以5‘-GGAA/T-3’为核心序列的富嘌呤序列。此域 代表了一个新的，但尚未确定的DNA结合基序，没有同源性 到其他DNA结合结构。PU.1结构域已经结晶 在与DNA的络合物和高分辨率的x射线衍射数据 收好了。在本项目中，碘化DNA和重金属取代 蛋白质将被用来解决复合体的晶相 通过多种同构置换方法。将使用原子模型 了解内毒素相关功能的分子基础 转录因子并评价它们在肿瘤发生发展中的作用。 癌症。将使用从DNA结合结构域获得的经验 表达和纯化PU1全长蛋白用于结晶和 结构分析。这种结构将揭示出结构-功能 激活结构域与DNA结合域的关系。

Transcription factors bind to a specific DNA sequence and regulate important metabolic functions such as cell growth, development and differentiation. There is great interest in understanding the function of these regulatory proteins, especially when their role is linked to oncogenesis. The PU.1 transcription factor is a member of the ets gene family that have been implicated in the development of erythroid leukemia and tumorigenesis in breast cancers. The ets proteins share a conserved region of 85 amino acids (the ETS domain) that binds DNA and recognizes a purine-rich sequence with the core sequence: 5'-GGAA/T-3'. This domain represents a new, yet uncharacterized DNA-binding motif, with no homology to other DNA-binding structures. The PU.1 domain has been crystallized in complex with DNA and high resolution x-ray diffraction data have been collected. In this project, iodinated DNA and heavy metal-substituted protein will be used to solve the crystallographic phases of the complex by multiple isomorphous replacement methods. Atomic models will be used to understand the molecular basis for the function of ets-related transcription factors and to evaluate their role in the development of cancer. The experience gained from the DNA-binding domain will be used to express and purify full-length PU.1 protein for crystallization and structure analysis. This structure will reveal the structure-function relationship of the activation domain to the DNA-binding domain.