Activities of nucleoprotein complexes visualized in single-molecule experiments

描述（由申请人提供）：对生物的机械理解需要我们了解蛋白质和DNA如何相互作用以产生功能性染色体。这一认识对于保护人类健康、应对遗传疾病和对抗病原微生物至关重要。提议的项目集中在单分子分析，允许生物分子相互作用的直接可视化，并可用于详细分析蛋白质- dna相互作用。该提案的目的包括仔细研究从DNA中去除蛋白质的“交换”机制，这表明对DNA上蛋白质转换的传统描述进行重大修订，并将影响基因调控和染色体结构蛋白质的广泛研究。第二个目标是直接研究在真核细胞中介导染色体折叠的大型“染色体结构维持”蛋白复合物的机制。最后，第三个目标集中在“剪切和粘贴”DNA重组系统家族的潜在机制上，该系统部分负责产生细菌遗传多样性。提出的对dna加工机制的高度机械分析将使我们对细胞如何解释、折叠和改变其基因组有更深入的了解，从而更好地了解这些功能受损的病理情况，并更好地了解如何在致病生物体中靶向这些功能。

DESCRIPTION (provided by applicant): Mechanistic understanding of living things requires our understanding of how proteins and DNA interact together to generate functional chromosomes. This understanding is central to preserving human health, dealing with genetic disorders, and fighting pathogenic organisms. The proposed projects are focused on single-molecule analyses which permit direct visualization of biomolecule interactions, and can be used to analyze protein-DNA interactions in detail. The aims of the proposal include careful study of an "exchange" mechanism for removal of proteins from DNA that suggests a major revision of conventional descriptions of protein turnover on DNA, and which will affect a wide range of studies of gene regulatory and chromosome-structural proteins. A second aim is focused on direct study of mechanisms of large "Structural Maintenance of chromosomes" protein complexes which mediate the folding of chromosomes in eukaryote cells. Finally, a third aim is focused on mechanisms underlying a family of "cut and paste" DNA recombination systems responsible in part for generating bacteria genetic diversity. The highly mechanistic analyses of DNA-processing machinery that are proposed will give us a stronger understanding of how cells interpret, fold and change their genomes, leading to a better understanding of pathologies where those functions are impaired, and better understanding of how to target those functions in pathogenic organisms.