Features of transposon Tn125, carrying the blaNDM-1 and blaNDM-2 genes. Genes and their transcription orientations are indicated by arrows. The lengths of the target genes and the exact location of the target site are not to scale. oriIS of ISCR21 is indicated by a circle. The 3-bp Tn125 target sites identified in each isolate are underlined and uppercase. GC content is indicated in percentages. Gene names are abbreviated according to their corresponding proteins: iso for phosphoribosylanthranilate isomerase; tat for the twin-arginine translocation pathway signal sequence protein; dvt for the divalent cation tolerance protein; Δpac for truncated phospholipid acetyltransferase; rhs for the Rhs protein; orf for an unknown open reading frame; and mfs for major facilitator superfamily metabolite/H+ symporter. IRL and IRR indicate inverted repeat left and right, respectively.