Phage Mu is the most efficient transposable element known, its high efficiency being conferred by an enhancer DNA element. Transposition is the end result of a series of well choreographed steps that juxtapose the enhancer and the two Mu ends within a nucleoprotein complex called the 'transpososome.' The particular arrangement of DNA and protein components lends extraordinary stability to the transpososome and regulates the frequency, precision, directionality, and mechanism of transposition. The structure of the transpososome, therefore, holds the key to understanding all of these attributes, and ultimately to explaining the runaway genetic success of transposable elements throughout the biological world. This review focuses on the path of the DNA within the Mu transpososome, as uncovered by recent topological analyses. It discusses why Mu topology cannot be analyzed by standard methods, and how knowledge of the geometry of site alignment during Flp and Cre site-specific recombination was harnessed to design a new methodology called 'difference topology.' This methodology has also revealed the order and dynamics of association of the three interacting DNA sites, as well as the role of the enhancer in assembly of the Mu transpososome.

中文翻译：

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亩转座子通过拓扑透镜。

噬菌体Mu是已知的最有效的转座因子，其高效率由增强子DNA元素赋予。转座是一系列精心设计的步骤的最终结果，这些步骤将增强子和两个核糖核酸末端（称为“转座体”）内的两个Mu末端并置。DNA和蛋白质成分的特殊排列为转座体赋予了非凡的稳定性，并调节了转座的频率，精度，方向性和机制。因此，转座体的结构是理解所有这些属性，并最终解释整个生物世界中转座因子失控遗传成功的关键。这篇综述着重于Mu转座体中DNA的途径，正如最近的拓扑分析所未发现的那样。它讨论了为何无法通过标准方法分析Mu拓扑，以及如何利用Flp和Cre特定位置重组过程中的位点对齐几何知识来设计一种称为“差异拓扑”的新方法。该方法学还揭示了三个相互作用的DNA位点缔合的顺序和动力学，以及增强子在Mu转座子装配中的作用。