Transposons Tn 10 and Tn 5

Abstract

ABSTRACT The study of the bacterial transposons Tn 10 and Tn 5 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 Tn 10 antisense system as a platform to develop riboregulators for applications in synthetic biology. Over the past decade two new regulators of both Tn 10 and Tn 5 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 Tn 10 and Tn 5 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 Tn 10 and Tn 5 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 Tn 10 and synthetic biology, some recent work that incorporates the Tn 10 antisense RNA into both transcriptional and translational riboswitches is summarized.