INTERACTIONS OF SEQUENCE-GENERAL DNA-BINDING PROTEINS

描述：总体目标是研究 通过高分辨率晶体结构的蛋白质-DNA相互作用 分析了一些序列通用的DNA结合蛋白及其 与DNA的复合物。 特别是， 古细菌（Sulfolobus）和细菌（E. 大肠杆菌）与 双链DNA和噬菌体单链DNA结合蛋白 与ssDNA复合将是主要焦点。 具体目标一。双链DNA结合蛋白。 (A)Sac 7 d和Sso 7 d 是两种dsDNA结合蛋白，发挥着稳定的重要作用 超嗜热古细菌中的双链DNA。 王博士获得了高质量的 与DNA结合的Sac 7 d和Sso 7 d的晶体（分辨率在1.3埃到1.5埃之间）， 1.9埃）。 他将研究：（1）新的DNA结合模式， Sac 7 d/Sso 7 d通过蛋白质-DNA复合物的结构分析， (2)DNA在扭结位点的构象调节，（3） 使用蛋白质的定点突变体的蛋白质构象调节 Sac7d/Ddo7d。 (B)HU蛋白来源于E.大肠杆菌是一种细菌染色质蛋白 形成“核小体样”结构。 王博士获得了 结合到DNA八核苷酸的HU蛋白的衍射质量晶体。 他建议解决这个HU-DNA复合物的结构，以其最高 解决可能。 古细菌染色体蛋白质的比较 （Sac 7 d，HMfb），细菌（HU）和真核细胞（组蛋白）王国将被 有助于理解染色质组织的进化。 具体目标二。 单链DNA结合蛋白在DNA合成中是重要的。 许多细胞的生命周期。 王博士已经确定了1.6埃 M13噬菌体基因V蛋白（GVP）的解析结构， 提出了一个超热蛋白质-DNA复合物的模型。 他将决定 与DNA六聚体复合的M13 GVP的晶体结构， 允许直接观察蛋白质-DNA相互作用。 此外，本发明还提供了一种方法， 来自另一个I2-2噬菌体（108 a.a）的GVP将在优于 2.0埃分辨率。 上述蛋白质-DNA系统将用低温X射线晶体学进行研究 其结构与生物学功能相关。 其他 必要时还将采用生物物理技术。 这些研究 将大大提高我们对这些生物功能的理解， 序列通用DNA结合蛋白。

DESCRIPTION: The overall aim is to investigate the molecular basis of protein-DNA interactions through the high resolution crystal structural analysis of a number of sequence-general DNA-binding proteins and their complexes with DNA. In particular, chromosomal proteins from archaeabacteria (Sulfolobus) and bacteria (E. coli) complexed to double-stranded DNA and bacteriophage single-stranded DNA binding proteins complexed to ssDNA will be the major focus. Specific Aim I. Double-stranded DNA-binding proteins. (A) Sac7d and Sso7d are two dsDNA-binding proteins that play the important role of stabilizing dsDNA in hyperthermophile archabacteria. Dr. Wang has obtained high quality crystals of Sac7d and Sso7d bound to DNA (resolution between 1.3 Angstrom to 1.9 Angstrom). He will study: (1) the novel DNA-binding mode of Sac7d/Sso7d through the structural analysis of the protein-DNA complexes, (2) the conformational modulation of DNA at the kink site, (3) the conformational modulation of proteins using site-directed mutants of Sac7d/Ddo7d. (B) HU protein from E. coli is a bacterial chromatin protein that forms a "nucleosome-like" structure. Dr. Wang has obtained diffraction-quality crystals of HU protein bound to a DNA octanucleotide. He proposes to solve the structure of this HU-DNA complex to its highest resolution possible. Comparison of chromosomal proteins from archaea (Sac7d, HMfb), bacterial (HU) and eucaryotic (histones) kingdoms will be useful in the understanding of the evolution of chromatin organization. Specific Aim II. Single-stranded DNA-binding proteins are important in the life cycle of many cells. Dr. Wang has determined the 1.6 Angstrom resolution structure of the M13 bacteriophage gene V protein (GVP) and proposed a model for its superheical protein-DNA complex. He will determine the crystal structure of the M13 GVP complexed with DNA hexamers which will allow a direct visualization of the protein-DNA interaction. In addition, the GVP from another I2-2 phage (108 a.a) will be analyzed at better than 2.0 Angstrom resolution. The above protein-DNA systems will be studied by cryo x-ray crystallography and their structures correlated with biological functions. Other biophysical techniques will also be employed when needed. These studies will greatly improve our understanding on the biological functions of those sequence-general DNA-binding proteins.