The Transfer Origin for Bacteroides Mobilizable Transposon Tn4555 Is Related to a Plasmid Family from Gram-Positive Bacteria

Abstract

Conjugal transfer of Bacteroides mobilizable transposon Tn4555 was examined with an Escherichia coli-based assay system. It was shown that mobilization required the cis-acting oriTTn region and that the Tn4555 mobATn gene and RK231 must be present in trans. With alkaline agarose gel electrophoresis and filter blot hybridizations, it was shown that at oriTTn there was a site- and strand-specific cleavage event that was dependent on mobATn. The 5* end of this cleavage site was mapped by primer extension, and the nucleotide sequence surrounding the site had homology to a family of oriT nick sites found in mobilizable plasmids of gram-positive bacteria. Removal of the nick site by deletion of 18 bp surrounding the site resulted in a significant loss of transfer activity. Originally published Journal of Bacteriology, Vol. 180, No. 2, Jan 1998