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Figure 1 | BMC Microbiology

Figure 1

From: Mouse skin passage of a Streptococcus pyogenes Tn917 mutant of sagA/pel restores virulence, beta-hemolysis and sagA/pel expression without altering the position or sequence of the transposon

Figure 1

Comparison of the sagA/pel region in chromosomal DNA from the non-mouse-passaged β-hemolysis negative sagA/pel::Tn917 mutant and the mouse-passaged kidney-recovered (KR) β-hemolysis positive variant. A). XL-PCR. The sagA/pel region from wild type CS101 (wt), sagA/pel – (pel::Tn917) and sagA/pel ::Tn917 kidney-recovered (KR) was amplified by XL-PCR and sagA/pel specific primers. The position of wild type and sagA/pel::Tn917 amplification products are indicated to the left of the figure. Apparent molecular weights are indicated to the right of the figure. The size of the XL-PCR products was consistent with a Tn917 insertion into the sagA/pel region [4]. B). Schematic of the sagA/pel::Tn917 region from non mouse-passaged (pel::Tn917) and mouse-passaged kidney-recovered (KR) isolates. The schematic shows that the sagA/pel ORF (shaded box), sagA/pel upstream region (empty box) and the right end of the Tn917 transposon (hatched box) were identical between the two strains. C). Chromosomal DNA was isolated from the two strains and directly sequenced as described in Materials and Methods and the sequences were found to be identical. The bold text is 267 bases of sequence that covers the promoter and 5' end of the sagA/pel gene. This sequence is identical to bases 598525 through 598792 of the annotated S. pyogenes genome [43] The text in regular type shows 301 bases of sequence from the Tn917 transposon including the right terminal repeat and the 3' end of the transposase gene.

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