A transposon carrying the gene mphB for macrolide 2 '-phosphotransferase II

The mphB gene for macrolide 2'-phosphotransferase II is located on two plas mids, pTZ3721 and pTZ3723, in Escherichia coli BM2506. We examined transloc ation of mphB that originated from pTZ3721. The transposable element carryi ng mphB is 39 kb long and has a Tn21-like transposition module at one end a nd a Tn1721-like transposition module at other. The structure of the transp osition modules of this element resembles that of Tn2610. However: the gene arrangement of the internal region on the transposon carrying mphB was rev erse to that of Tn2610. The nucleotide sequences of both terminal regions s uggested that the inversion of the DNA fragment occurred between the res si tes by resolvase-mediated recombination. (C) 2000 Federation of European Mi crobiological Societies. Published by Elsevier Science B.V. All rights rese rved.