Fig. 3
From: Characterization of the novel In1059 harbouring VIM gene cassette
Genetic structures and proposed mobilization and evolution of In0 to In1059 and the analysis of intI1 and attC in class 1 integrons from this study. I, genetic structures and putative mobilization. A, In0; B, A + GCaadB; C, B + GCaadA16; D, C + GCaacA4’-3; E, In1059 = D + GCbla VIM-5 + IS26 + (sul1 + orf5) (replacing sulΔ1); II, Sequences and structures of attI1 (59-be, 59-base elements) and attC. II-a, the attI1 (59-be) site positions are denoted by the bold black line. Open bars indicate potential IntI1 recognition sites, and arrows under the 7-bp core sites indicate relative orientations. The 7-bp core site sequences are shown in bold type, and the strong and weak IntI1-binding sites and direct repeats, DR1 and DR2, are indicated in accordance with the literature [29]. The simple site locations are denoted by an open bar. The “aacaaag(a)” sequences in the black boxes are reminiscent of the spacer in attI1 and occur between the two gene cassettes; recombination or excision of gene cassettes occurs frequently at these sites as indicated in panel I, process C to D. II-b, the attC sequences of class 1 integrons. The bold black letters denote the 7-bp core site, while the numbers are the nucleotide positions (left, negative, right, positive) of the recombination cross-over points, as indicated by a vertical arrow where the recombination or excision of gene cassettes regularly occurs, as shown in panel I. The GenBank accession numbers are shown on the left-hand side of the diagram