Linearized partial map of p8E072658 encoding a new allele of mcr-4 within Tn6926. The horizontal central black lines represent the plasmid backbone. The arrows indicate gene orientation, and the boxed arrows represent IS. The grey shadings demonstrate significant percentage identities, marked in red. The genes/ORFs are labelled below according to their associated functions and the key is shown on the right. Iterons are shown in orange bars preceding the rep genes. Small vertical black bars labelled C/D or D/C represent the two pdif recombination sites (XerC/D or XerD/C). The long vertical bars (marked IRL and IRR) denote Tn6926. The scale bar is shown below and drawn to scale from GenBank accession numbers CP061706 (p8E072658), MK360916.1 (pAB18P065-MCR-4.3), CP038265.1 (pEC_mcr 4.3), CP038261.1 (pEH_mcr 4.3), CP033872.1 (pAb-MCR-4.3) and CP100354.1 (pYULZMPS10) and chromosome of Shewenella vesiculosa strain M7 from accession no. CP073588.1.