Figure 2.

Genetic organization of ORFs in the contig harboring the tetracycline resistance gene tet(S) from the genome sequence of S. thermophilus St-9 (A) and in the contig harboring the erythromycin resistance gene ermB from the genome of S. thermophilus St-5 (B). Color code of the ORFs: in yellow, ORFs complete and/or incomplete ORFs related to transposases, invertases, and topoisomerases; in purple, ORFs involved in antibiotic resistance; in light blue, ORFs related to plasmid segregation and stability; in green, ORF involved in conjugation/mobilization; in white, ORFs encoding hypothetical proteins or proteins coding for other systems. Specific features of (B): (i) the position of oriT is also indicated; (ii) arrowheads represent a region of direct repeats (DR) in front of the replication module, which showed no significant homology to those in pRE25 and pSM19035; (iii) long segments of the contig (black bars) highly similar (>99% nucleotide identity) or identical to plasmid sequences of pRE25 from Enterococcus faecalis and pSM19035 from Streptococcus pyogenes, as indicated; (iv) numbering in plasmids indicates start and end positions of regions of homology to sequences in the contig; (v) purple bars, constituted by truncated insertion sequence (IS) elements, separate non-colinear regions of homology; (vi) blue bars indicate regions of low homology to those found in pRE25 and pSM19035; (vii) the broken line indicates sequences not present in pSM19035.