TABLE 1.
Bacterial strains and plasmids used in this study
| Strain or plasmid | Genotype or description |
|---|---|
| Serovar Typhimurium | |
| TN1246 | leuBCD485 pepB11 pepN90 pepA16 supQ302 Δ(proAB pepD) pepP1 pepQ1 |
| TN2617 | TN1246/pJG97 |
| TN2654 | leuBCD485 pepB11 pepN90 pepA16 supQ302 Δ(proAB pepD) pepP1 pepQ1 pepE1 pepT1 recA sor::Tn10 |
| TN4804 | TN2654/pCM265 |
| E. coli | |
| CM89 | leu-9 pepB1 pepN102 pepA11 pepQ10 Δpro-lac met |
| TN5179 | CM89/pCM370 |
| Plasmids | |
| pBluescript SK II(+) | Plasmid cloning vector (Stratagene) |
| pBR328 | Plasmid cloning vector (a derivative of pBR322; New England Biolabs) |
| pSE380 | Plasmid cloning vector containing Ptrc promoter and ribosome binding site |
| pJG97 | 10.7-kb fragment carrying the serovar Typhimurium pepB gene cloned into the BamHI site of pBR328 |
| pCM236 | 11.1-kb subclone of pJG97 obtained after SalI digestion of pJG97 |
| pCM265 | 2.1-kb SalI/PstI fragment of pJG236 carrying the pepB gene cloned into SalI-PstI-digested pBluescript SK II(+) |
| pCM370 | 1.329-kb fragment containing the ribosome binding site and the ORF of the serovar Typhimurium pepB gene amplified by PCR and cloned into EcoRI-KpnI-digested pSE380 vector |