Repeated sequences isolated from Bordetella pertussis induce DNA rearrangements and deletions at high frequency

Two repeated sequences (RS) from Bordetella pertussis were cloned in Escherichia coli and sequenced. The RS, called RSBP1 and RSBP3, are highly homologous to other B. pertussis RS. The recombinant plasmids containing RSBP1 and RSBP3 or transposon-like structures of these elements were not stable but segregated plasmids with deletions or rearranged DNA. RS of B. pertussis seem to be able to stimulate both intra- and inter-genomic RecA-independent recombination events. In at least one case, the observed deletion had occurred precisely between the RS terminus and a site with sequence homology to the terminus. The high frequency rearrangements associated with the RS imply that the RS are transposable elements.