INTERACTIONS OF SEQUENCE-GENERAL DNA-BINDING PROTEINS

描述：总体目标是研究人类免疫缺陷的分子基础 蛋白质-DNA通过高分辨晶体结构的相互作用 几种序列通用DNA结合蛋白及其相互作用的分析 与DNA形成复合体。特别是，来自于 古细菌(Sulfolobus)和细菌(E.Coli)复合成 双链DNA和噬菌体单链DNA结合蛋白 与单链DNA的络合作用将是研究的主要焦点。 具体目的1.双链DNA结合蛋白。(A)Sac7d和Sso7d 是两种发挥稳定作用的dsDNA结合蛋白 超高温古生菌中的dsDNA。王博士获得了高质量的 Sac7d和Sso7d与DNA结合的晶体(分辨率在1.3埃到 1.9埃)。他将研究：(1)新的DNA结合模式 Sac7d/Sso7d通过蛋白质-DNA复合体的结构分析， (2)DNA在扭结部位的构象调制；(3) 利用蛋白质的定点突变体调节蛋白质的构象 Sac7d/Ddo7d。(B)来自大肠杆菌的Hu蛋白是一种细菌染色质蛋白 这形成了一种“核小体样”结构。王博士已经获得了 结合到DNA八核苷酸上的HU蛋白的衍射级晶体。 他建议将这种Hu-DNA复合体的结构解决到最高水平 可能会有解决办法。古生菌染色体蛋白质的比较 (Sac7d，HMFB)，细菌(HU)和真核(组蛋白)王国将是 有助于理解染色质组织的进化。 特定目的II.单链DNA结合蛋白在 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)的分辨结构和 提出了其超分子蛋白质-DNA复合体的模型。他会决定 M13 GVP与DNA六角体的晶体结构 允许蛋白质-DNA相互作用的直接可视化。此外, 来自另一个I2-2噬菌体(108 A.A)的GVP将在比 2.0埃分辨率。 上述蛋白质-DNA体系将用低温x射线结晶学进行研究。 它们的结构与生物功能相关。其他 必要时还将采用生物物理技术。这些研究 将极大地提高我们对这些细胞生物学功能的理解 序列--一般的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.