Gyrase Binding Sites in Bacteriophage Mu Transposition and Chromosome Structure

9420804帕托噬菌体Mu由于其既是病毒又是转座子的性质，在转座子中不寻常的是其大尺寸和高转座频率。在裂解周期期间，Mu DNA的扩增通过在细菌类核内发生的一系列复制性转座事件发生，尽管该体的复杂结构施加了限制。对类核内前噬菌体DNA末端突触的潜在问题的担忧（转座过程的早期步骤）导致了在Mu基因组中心发现了有效复制所需的强促旋酶结合位点的研究。提出了一个假说，即促旋酶位点参与组织超螺旋原噬菌体DNA的拓扑结构，以帮助Mu末端的突触。在上一个资助期间对该模型的几个预测进行了测试，迄今为止的结果为该假设提供了强有力的支持。本研究继续与穆的研究，并将其扩展到包括强促旋酶结合位点在染色体结构中的可能作用的研究。将测试Mu强促旋酶位点可以帮助将与促旋酶位点等距的相互作用DNA序列聚集在一起的预测，并将检查促旋酶和该活性所需的结合位点的特征。一个强有力的选择程序，用于分离和表征潜在的强促旋酶结合位点的E。大肠杆菌染色体。染色体DNA片段将被克隆到原噬菌体的中心，其促旋酶位点被删除，因此不能形成噬斑;任何恢复噬斑形成能力的片段将是携带强促旋酶位点的片段的候选者。 本研究中对细菌和病毒复制的研究有可能提供有用的信息，以干扰其他生物体中的病毒生长。 *** ??

9420804 Pato Bacteriophage Mu/ by nature of its being both a virus and a transposon, is unusual among transposons in its large size and its high frequency of transposition. Amplification of Mu DNA during the lytic cycle occurs by a series of replicative transposition events which take place within the bacterial nucleoid, despite the restraints imposed by the complex structure of that body. Concerns about potential problems with synapsing the ends of prophage DNA within the nucleoid, an early step in the transposition process, led to studies which uncovered a strong gyrase binding site in the center of the Mu genome which is required for efficient replication. An hypothesis was proposed that the gyrase site is involved in organizing the topology of the supercoiled prophage DNA to assist in synapsis of the Mu ends. Several predictions of the model were tested during the previous grant period and the results to date offer strong support for the hypothesis. The present research continues the studies with Mu and extends them to include studies on the possible role of strong gyrase binding sites in chromosomal structure. The prediction that the Mu strong gyrase site can assist in bringing together interacting DNA sequences that are equidistant from the gyrase site will be tested/ and features of gyrase and of the binding site that are required for this activity will be examined. A powerful selection procedure for the isolation and characterization of potential strong gyrase binding sites from the E. coli chromosome is presented. Fragments of chromosomal DNA will be cloned into the center of a prophage deleted for its gyrase site, and hence unable to form a plaque; any fragment that restores plaque forming ability will be a candidate for one carrying a strong gyrase site. %%% Studies of bacterial and viral replication in this research have the potential to provide information useful in interfering with virus growth in other organisms. *** ??