Excision of transposon Tn5 is dependent on the inverted repeats but not on the transposase function of Tn5.

Abstract

The excision of the Kanamycin resistant determinant Tn5 from sites of insertion in the Escherichia coli genome was studied by examining the reversion of lac::Tn5 insertion mutations to lac+. The frequency of excision depended on the site of Tn5 insertion, excision occurred efficiently in RecA- cells, excision did not require a Tn5-encoded transposition function and efficient excision required the inverted repeats of Tn5. Excision of Tn5 may be similar to the formation of spontaneous deletions and may occur by slippage during DNA synthesis.