Transposition of Bacteriophage Mu DNA

我们的目标是了解移动遗传元件转位的分子机制。我们研究噬菌体Mu，因为在Mu转位中使用的机制与其他可移动的遗传元件（原核和真核）非常相似。因此，Mu作为溶原病毒和转座子的独特性质允许使用体内生化研究，这在低转座子频率的系统中是困难或不可能的。在目前的资助期内，我们将重点了解位于Mu基因组中心的新型转座增强子（CEN）的作用，该增强子包含一个强DNA旋切酶结合位点。我们将测试在其他系统中使用类似cen的增强器的模型。CEN是目前已知的具有特定功能的回转酶结合位点的最清晰的例子。对其作用机制的研究不仅有助于理解回转酶在转位中的作用，而且有助于理解回转酶在大型DNA结构（如原核生物的类核）的组织中的作用。

Our objective is understanding molecular mechanisms of transposition of mobiles genetic elements. We study bacteriophage Mu, as mechanisms used in Mu transposition are highly analogous to those of other mobile genetic elements, prokaryotic and eukaryotic. Thus unique properties of Mu as a lysogenic virus and a transposon allow use of in vivo biochemical studies which are difficult or impossible in systems with low frequency of transposition. During the present grant period, we will focus on understanding the role of a novel transposition enhancer (CEN), located in the center of the Mu genome, which contains a strong DNA gyrase binding site. We will test models for use of CEN-like enhancers in other systems. CEN is the clearest example presently available of a gyrase binding site with a specific function. Study of its mechanism of action should help in understanding not only the role of gyrase in transposition, but also in organization of large DNA structures such as the prokaryotes nucleoid.