Deletions within the trap plasmid pMEC1 generated in <i>P. versutus</i> UW400 upon transposition of IS<i>Pve1</i>.

<p>The range of the deletion within four individual derivatives of pMEC1 is shown by curved gray lines.</p

Genetic organization of the Tn<i>3</i> family transposons captured in <i>Paracoccus</i> spp. using trap plasmids.

<p>The cryptic transposon Tn<i>3434</i>a (A), Tn<i>5393</i> carrying streptomycin resistance genes (B) and the composite element Tn<i>Ppa1</i> flanked by two identical copies of Tn<i>3434</i> (C). Predicted coding regions are represented by arrows indicating the direction of transcription. Gray arrows indicate TPase genes (<i>tnpA</i>) and additional genes (including resolvase genes – <i>tnpR</i>) are indicated by white arrows. Inverted repeats (IRs) flanking transposons are marked by black arrowheads (IRL – left IR; IRR – right IR) and <i>res</i> sites are shown by black squares. Plots of the G+C content of the Tn<i>3434</i>a and Tn<i>5393</i> sequences are shown in panels A and B (the average value is given on the right).</p

Schematic overview of five ways in which transposition can deliver promoters to the transcriptionally silent tetA (tetracycline resistance) gene of the trap plasmid pCM132TC.

<p>The location of promoters in the plasmids pCM132TC::TE, conferring a Tc^r phenotype, are appropriately indicated: an outwardly oriented promoter in the terminal parts of a TE (A), a hybrid promoter composed of a −35 hexamer (delivered by the TE) and a −10 hexamer located in close proximity to the target site of transposition (B), the promoter of a TPase gene (C), a promoter present in the core region of a composite transposon (D), and a promoter derived from another plasmid delivered by the generation of transient co-integrates resulting from replicative transposition (E). DNA fragments used in the localization of the promoters are shown as open thin boxes below each panel. The activity of promoters (tested in <i>Paracoccus</i> spp.) accompanying the presence of the DNA fragments is indicated on the right: (+) promoter activity, (−) lack of promoter activity.</p

<i>Paracoccus</i> spp. strains used in this study.

<p><i>Paracoccus</i> spp. strains used in this study.</p

Transposable elements of <i>Paracoccus</i> spp. identified in this study.

a<p>The length of the IRs/the number of identical residues.</p>b<p>Location in plasmids, if applicable.</p

The distribution of TEs (identified in our studies) in the genomes of strains of <i>Paracoccus</i> spp.

<p>A specific DNA probe (fragment of a TPase gene amplified by PCR and DIG-labeled) was prepared for each TE and used in dot blot hybridization analysis with total DNA isolated from the <i>Paracoccus</i> spp. strains.</p

Genetic organization of the insertion sequences (A, B, C, D, E) and composite transposon Tn<i>6097</i> (F) of <i>Paracoccus</i> spp. identified in this study.

<p>The families and names of the identified ISs are shown on the panel. Inverted repeats (IRL – left IR; IRR – right IR) flanking ISs are marked by black arrowheads. Predicted coding regions are represented by arrows indicating the direction of transcription. Gray arrows indicate TPase genes and white arrows indicate additional ORFs present within the ISs and within the core of Tn<i>6097</i>. Two of the ORFs of Tn<i>6097</i> (ORF2 and ORF13) are truncated (the disruptions are most probably remnants of the ancient IS<i>Pfe2</i> transposition events that led to the formation of Tn<i>6097</i> in its native host). The predicted genetic modules of the transposon are indicated.</p