Recombination between two TnA transposon sequences oriented as inverse repeats is found less frequently than between direct repeats

Publisher Website
Google Scholar
Abstract
Inverse repeats of the transposon Tn2660 in either a ColEl or an R6K replicon, with or without inversions of the parental DNA sequences between the repeats, show no detectable (recA or recA + hosts. In contrast, attempts made to construct plasmids which carry two direct repeats by in vitro cleavage and ligation in a recA host were unsuccessful, although homologous plasmids with inverse repeats could be constructed, and other plasmids were found consistent with products of recombination between the direct repeats of a transient intermediate structure. It is concluded that in recA or recA + hosts recombination between direct repeats of a transposon is frequent, whereas recombination between inverse repeats of a homologous structure has not been observed. A model to explain this difference depends upon a mechanism that produces a nick in only one of the pair of strands at the internal resolution site (IRS) sequence of the transposon.