TABLE 1.
Strains and plasmids used in this study
| Strain or plasmida | Relevant genotype | Source or reference |
|---|---|---|
| Strains | ||
| S. enterica serovar Typhimurium | ||
| TN1246 | leuBCD485 pepN90 pepA16 pepB11 supQ302 Δ(proAB pepD) pepP1 pepQ1 | Laboratory collection |
| TN2540 | metE551 metA22 ilv-452 trpB2 hisC527 galE496 xyl-404 rpsL120 flaA66 hsdL6 hsdSA29 (r− m+) | Laboratory collection |
| TN2718 | leuBCD485 pepN90 pepA16 pepB11 supQ302 Δ(proAB pepD) pepP1 pepQ1 pepE8::MudJ | Laboratory collection |
| TN2719 | leuBCD485 pepE8::MudJ | Laboratory collection |
| TN5213 | leuBCD485 pepB11 pepN90 pepA16 supQ302 Δ(proAB pepD) pepP1 pepQ1 pepE8::MudJ/pCM389 | This study |
| TN5415 | leuBCD485 pepB11 pepN90 pepA16 supQ302 Δ(proAB pepD) pepP1 pepQ1 pepE8::MudJ/pCM441 | This study |
| TN5416 | leuBCD485 pepE8::MudJ/pCM441 | This study |
| E. coli | ||
| DH5α | Φ80lacZΔM15 Δ(lacZYA)U169 endA1 hsdR17 (rK− mK−) supE44 thi-1 recA1 gyrA96 relA1 | Gibco BRL |
| BMH71-18 mutS | thi supE Δ(lac-proAB) (mutS::Tn10) (F′ proAB lacIqZΔM15) | Clontech |
| B. subtilis DB104 | his | R. Switzer |
| Plasmids | ||
| pSE380 | Cloning vector with the ptrc inducible promoter; Ampr | 2 |
| pCM247 | 2.6-kb fragment containing pepE and flanking sequence in pBluescript II KS(+); Ampr | 6 |
| pCM389 | pepE from serovar Typhimurium cloned into the EcoRI and BamHI restriction sites of pSE380 | This study |
| pCM440 | pepE from B. subtilis cloned into the EcoRI and BamHI restriction sites of pSE380 | This study |
| pCM441 | pepE from X. laevis cloned into the EcoRI and BamHI restriction sites of pSE380 | This study |
a
Plasmids carrying mutated pepE are listed in Table 2, where the mutation is also indicated.