Molecular Analysis of Site Specific DNA Recombination

描述（由申请人提供）：遗传信息在 所有的细胞通常都涉及核蛋白复合物的有序组装， 随后以高度调节和精确的方式催化反应。 促成这一过程的因素包括序列特异性DNA结合 对于特定反应或反应类型是独特的蛋白质（例如， RNA聚合酶、特异性对照蛋白）、非特异性（或弱 序列特异性）DNA结合蛋白，其促进或特异性 调节许多不相关的反应，以及DNA的高级结构（例如， 超螺旋，染色质结构）。我们工作的一个主题是试图 将这些因素整合到对单个模型全面理解中 反应. 我们将继续对Hin催化的 来自沙门氏菌的位点特异性DNA倒位反应。这些目标 确定反应中间体的分子结构， Fis通过其激活Hin重组酶，以及DNA交换的机制。 Fis在Hin反应中的作用将与主要的DNA形成对比。 Fis与噬菌体特异性Xis蛋白结合的结构功能 调节噬菌体λ位点特异性重组。Fis的细胞水平 E.卷曲在不同的生长条件下变化，从最丰富的 类核蛋白几乎不存在。我们将评估 Fis在控制全球基因表达模式中的作用， 对Fis调节的生理学理解。详细研究具体 监管区域也将继续，特别是在阐明 Fis-RNA聚合酶相互作用的性质。HMG 1/2 DNA结合和 弯曲蛋白是真核生物中最丰富的成分之一， 染色质，虽然他们的具体生物活性知之甚少。 我们将研究它们的DNA结合特性如何与它们的功能相关。 在不同反应中的作用，特别强调S。酿酒酵母NHP 6A。

DESCRIPTION (provided by applicant): The processing of genetic information in all cells often involves the ordered assembly of nucleoprotein complexes that subsequently catalyze reactions in a highly regulated and precise manner. Factors contributing to this process include sequence-specific DNA binding proteins that are unique for a particular reaction or type of reactions (e.g., RNA polymerase, specific control proteins), non-specific (or weakly sequence-specific) DNA binding proteins that facilitate or specifically regulate many unrelated reactions, and the higher-order structure of DNA (e.g., supercoiling, chromatin structure). A theme of our work is to attempt to integrate these factors into a comprehensive understanding of individual model reactions. We will continue with a detailed investigation of the Hin-catalyzed site-specific DNA inversion reaction from Salmonella. The goals are to determine the molecular structures of the reaction intermediates, the process by which Fis activates the Hin recombinase, and the mechanism of DNA exchange. The role of Fis in the Hin reaction will be contrasted with the primarily DNA architectural function of Fis combined with the phage-specific Xis protein in regulating phage lambda site-specific recombination. Cellular levels of Fis in E. coil vary under different growth conditions, from being the most abundant nucleoid-associated protein to being near absent. We will assess the role of Fis in controlling global gene expression patterns to gain a broad physiological understanding of regulation by Fis. Detailed studies on specific regulatory regions will also continue, particularly with respect to elucidating the nature of Fis-RNA polymerase interactions. The HMG1/2 DNA binding and bending proteins are one of the most abundant constituents of eukaryotic chromatin, although their specific biological activities are poorly understood. We will investigate how their DNA binding properties relate to their functional roles in different reactions with particular emphasis on S. cerevisiae NHP6A.