TABLE 1.
Strains and plasmids used in the study
| Strain or plasmid | Genotype and/or relevant characteristics | Reference or source |
|---|---|---|
| Y. pestis strains | ||
| CO92 | pgm+ pYV+ pMT1+ pPCP1+ | Centers for Disease Control, Fort Collins, CO |
| CO92 ompX+/ompX::aph | pgm+ pYV+ pMT1+ pPCP1+ompX+ with integrated pMHZ3; merodiploid for ompX | This study |
| CO92 ΔompX::aph | pgm+ pYV+ pMT1+ pPCP1+ ΔompX::aph | This study |
| KIM6+ | pgm+ pYV− pMT1+ pPCP1+ | 26 |
| KIM6+ ΔompX::npt | pgm+ pYV− pMT1+ pPCP1+ ΔompX::npt | 26 |
| E. coli K-12 strains | ||
| DH5α | F−endA1 glnV44 thi-1 recA1 relA1 gyrA96 deoR nupG φ80dlacZΔM15 Δ(lacZYA-argF)U169 hsdR17(rK− mK+) | Invitrogen |
| TOP10 | F−mcrA Δ(mrr-hsdRMS-mcrBC) φ80lacZΔM15 ΔlacX74 nupG recA1 araD139 Δ(ara-leu)7697 galE15 galK16 rpsL(Strr) endA1 | Invitrogen |
| D21 | F−proA23 lac-28 tsx-81 trp-30 his-51 rpsL173(Strr) ampCp-1 | H. G. Boman, Coli Genetic Stock Center, Yale University |
| D21e7 | F−proA23 lac-28 tsx-81 trp-30 his-51 rpsL173(Strr) rfa-1 ampCp-1 | H. G. Boman, Coli Genetic Stock Center, Yale University |
| D21f1 | F−proA23 lac-28 tsx-81 trp-30 his-51 rpsL173(Strr) rfa-21 rfa-1 ampCp-1 | H. G. Boman, Coli Genetic Stock Center, Yale University |
| D21f2 | F−proA23 lac-28 tsx-81 trp-30 his-51 rpsL173(Strr) rfa-31 rfa-1 ampCp-1 | H. G. Boman, Coli Genetic Stock Center, Yale University |
| CC118 λpir | r− m+ λpir+; cloning strain | 12 |
| SM10 λpir | thi-1 thr leu tonA lacY supE recA::RP4-2-Tc::Mu Kmr λpir+; conjugation strain | 51 |
| Plasmids | ||
| pPCR2.1-TOPO | Ampr Kmr | Invitrogen |
| pOmpX | pPCR2.1-TOPO carrying ompX gene with its native promoter from Y. pestis | This study |
| pTA | ompX− control plasmid derived from pOmpX by deletion of the fragment between EcoRI restriction enzyme-cut sites | This study |
| pMHZ1 | mob+, pir-dependent oriR6K, sacBR Cmr containing y1324ompX gene from Y. pestis | 26 |
| pMHZ3 | pMHZ1 containing ΔompX::aph | This study |
| pGP704 | mob+, pir-dependent oriR6K, Ampr | J. J. Mekalanos, PlasmID, Harvard Medical School |
| pRL250 | sacBR+ | 52 |
| pGP704.L | pGP704 containing sacBR cloned from pRL250 | This study |
| pGP704.O | pGP704.L containing ΔompX::aph; allelic exchange plasmid | This study |