Schematic diagram of the NDM-1 region of pTR3 and pTR4, compared to those from the other known plasmids.

The bla_NDM-1 (red), and nearby IS elements (various colors) are shown. ORFs are depicted with arrows and the IRs were depicted by short vertical bars. The regions corresponding to possible vestiges of unknown IS identified in pTR3/4 and p271A are marked by yellow rectangles. Nucleotide sequences of the two regions are shown in the boxes, of which the 39-bp putative IRs are underlined. Corresponding repeat sequences in the boxes are shown in the same color. Differences are shown in lower case.