Structure and Function of Nucleosome Assembly Protein 1

染色质起着两个重要的作用，但就其本质而言，它们是相互排斥的。一方面， 染色质负责DNA压缩的极端程度， 基因组以适应细胞核的范围。另一方面，它必须允许当地的解体， 让细胞机器进入基因组。介导相互转化的活动 在不同水平的紧密染色质状态之间， 需要获取基因组DNA的过程。机械和结构的洞察力， 生物学相关的过程是有限的。在这里，核小体组装蛋白1的作用 （NAP1）家族在维持和调节染色质结构中的作用， 将研究流动性。目的1和2解决分子伴侣的结构和分子基础 与组蛋白的相互作用，使用X射线衍射以及生物化学和体内方法。的 NAP1介导的组蛋白去除和组蛋白交换的机制和生物学作用将是 通过严格的动力学分析结合染色质结构的体内检查（目的 3）。最后，翻译后修饰调节NAP1活性的新假设， 后生动物将在目标4中接受测试。这一建议的力量在于广泛的 一系列的结构、生物物理、生物化学和遗传学方法，以解决 这是一个重要的问题，紧凑的DNA是如何提供给细胞机器的。

Chromatin plays two essential, yet by their very nature mutually exclusive roles. On one hand, chromatin is responsible for the extreme degree of DNA compaction that allows the eukaryotic genome to fit into the confines of the nucleus. On the other hand, it must permit the local unraveling of DNA to grant access of the cellular machinery to the genome. Activities that mediate the interconversion between various levels of compacted chromatin states are key regulators of all processes requiring access to genomic DNA. Mechanistic and structural insight into these biologically relevant processes is limited. Here, the role of the nucleosome assembly protein 1 (NAP1) family of histone chaperones in maintaining and modulating chromatin structure and fluidity will be investigated. Aims 1 and 2 address the structural and molecular basis for chaperone interaction with histones, using x-ray diffraction as well as biochemical and in vivo approaches. The mechanism and biological role of NAP1-mediated histone removal and histone exchange will be studied by rigorous kinetic analysis combined with in vivo examination of chromatin structure (aim 3). Finally, the novel hypothesis that a posttranslational modification regulates NAP1 activity in metazoans will be put to test in aim 4. The strength of this proposal lies in a combination of a broad spectrum of structural, biophysical, biochemical and genetic approaches to address the highly significant question of how compacted DNA is made available to the cellular machinery.