The IS6 family of bacterial and archaeal insertion sequences, first identified in the early 1980s, has proved to be instrumental in the rearrangement and spread of multiple antibiotic resistance. Two IS, IS26 (found in many enterobacterial clinical isolates as components of both chromosome and plasmids) and IS257 (identified in the plasmids and chromosomes of gram-positive bacteria), have received particular attention for their clinical impact. Although few biochemical data are available concerning the transposition mechanism of these elements, genetic studies have provided some interesting observations suggesting that members of the family might transpose using an unexpected mechanism. In this review, we present an overview of the family, the distribution and phylogenetic relationships of its members, their impact on their host genomes and analyse available data concerning the particular transposition pathways they may use. We also provide a mechanistic model that explains the recent observations on one of the IS6 family transposition pathways: targeted cointegrate formation between replicons.

中文翻译：

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IS 6家族，是临床上很重要的一组插入序列，包括IS 26

IS6细菌和古细菌插入序列家族最早发现于1980年代初期，已被证明在多种抗生素抗性的重排和传播中发挥了作用。两种IS，IS26（在许多肠杆菌临床分离株中均作为染色体和质粒的组成部分）和IS257（在革兰氏阳性细菌的质粒和染色体中鉴定）因其临床影响而受到特别关注。尽管很少有关于这些元素转座机制的生化数据，但是遗传研究提供了一些有趣的观察结果，表明该家族成员可能会使用意想不到的机制进行转座。在这篇评论中，我们概述了该家族，其成员的分布和亲缘关系，它们对宿主基因组的影响，并分析有关它们可能使用的特定转座途径的可用数据。我们还提供了一种机理模型，该模型解释了对IS6家族转座途径之一的最新发现：复制子之间的靶向共整合形成。