Transposons Tn 10 and Tn 5

Abstract

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.

Detect accessible chromatin using ATAC-sequencing, from principle to applications

“…At present, the most commonly used transposase is the Tn5 transposase, which can transpose in the accessible chromatin more often than in the inaccessible chromatin. The Tn5 transposase acts as a probe for measuring chromatin accessibility at the genome-wide level through the “cut and paste” mechanism, and the transposon can simultaneously fragment and tag the unprotected regions of DNA with sequencing adapters [25, 26] (Fig. 1b and Fig.…”

The Escherichia Coli Hfq Protein: An Unattended DNA-Transactions Regulator

“…Hfq-mediated regulation of transcription of the gene coding for the IS50 transposase might also explain the inhibition of Tn5 transposition (see Transcription; Haniford and Ellis, 2015 ). Moreover, Crp (cyclic AMP receptor protein) was proposed to mediate Hfq effect on Tn5 transposition (Ross et al, 2014 ).…”

Antimicrobial Resistance in ESKAPE Pathogens

“…The canonical IS unit is composed of one or two genes required for mobility, flanked by terminal inverted repeats (IRs) (263,264). IS are capable of mobilizing neighboring genes (cargo genes) in structures called composite/compound transposons, where two copies of an identical or related IS mobilize the region between them (265,266). Classic examples of composite transposons associated with the carriage of AMR genes include Tn9 (IS1; chloramphenicol resistance), Tn10 (IS10; tetracycline resistance), Tn5 (IS50; aminoglycoside and bleomycin resistance) (262,265), and, more recently, Tn6330 (ISApl1), which is responsible for mobilizing the colistin resistance gene mcr-1 (135,262,267).…”