The Butyrivibrio fibrisolvens tet(W) gene is carried on the novel conjugative transposon TnB1230, which contains duplicated nitroreductase coding sequences

The Butyrivibrio fibrisolvens tet(W) gene is located on the conjugative transposon TnB1230. TnB1230 encodes transfer proteins with 48 to 67% identity to some of those encoded by Tn1549. tet(W) is flanked by directly repeated sequences with significant homology to oxygen-insensitive nitroreductases. The 340 nucleotides upstream of tet(W) are strongly conserved and are required for tetracycline resistance.