Department of Biochemistry, University of Western Ontario, London, Ontario N6A 5C1, Canada.
Microbiol Spectr. 2015 Feb;3(1):MDNA3-0002-2014. doi: 10.1128/microbiolspec.MDNA3-0002-2014.
The study of the bacterial transposons Tn10 and Tn5 has provided a wealth of information regarding steps in nonreplicative DNA transposition, transpososome dynamics and structure, as well as mechanisms employed to regulate transposition. The focus of ongoing research on these transposons is mainly on host regulation and the use of the Tn10 antisense system as a platform to develop riboregulators for applications in synthetic biology. Over the past decade two new regulators of both Tn10 and Tn5 transposition have been identified, namely H-NS and Hfq proteins. These are both global regulators of gene expression in enteric bacteria with functions linked to stress-response pathways and virulence and potentially could link the Tn10 and Tn5 systems (and thus the transfer of antibiotic resistance genes) to environmental cues. Work summarized here is consistent with the H-NS protein working directly on transposition complexes to upregulate both Tn10 and Tn5 transposition. In contrast, evidence is discussed that is consistent with Hfq working at the level of transposase expression to downregulate both systems. With regard to Tn10 and synthetic biology, some recent work that incorporates the Tn10 antisense RNA into both transcriptional and translational riboswitches is summarized.
对细菌转座子 Tn10 和 Tn5 的研究提供了大量关于非复制性 DNA 转座、转座体动力学和结构以及用于调节转座的机制的信息。目前对这些转座子的研究重点主要是宿主调节，以及利用 Tn10 反义系统作为平台开发用于合成生物学的核糖开关调节剂。在过去的十年中，已经确定了两种新的 Tn10 和 Tn5 转座的调节剂，即 H-NS 和 Hfq 蛋白。这些都是肠道细菌中基因表达的全局调节剂，其功能与应激反应途径和毒力有关，并且可能将 Tn10 和 Tn5 系统（以及抗生素耐药基因的转移）与环境线索联系起来。这里总结的工作与 H-NS 蛋白直接作用于转座复合物以上调 Tn10 和 Tn5 转座一致。相比之下，有证据表明 Hfq 作用于转座酶表达水平以下调两个系统。关于 Tn10 和合成生物学，总结了一些最近将 Tn10 反义 RNA 纳入转录和翻译核糖体开关的工作。
