TABLE 1.
Bacterial strains and plasmids used in this study
| Strain or plasmid | Relevant characteristics | Source or reference |
|---|---|---|
| Escherichia coli strains | ||
| DH5α | FsupE44 ΔlacU169(φ80dlacZΔM15) hsdR17(rK− mK+) recA1 endA1 gyrA96 thi-I relA1 | Bethesda Research Laboratories |
| MT616 | MT607(pRK600) | 8 |
| BL21(DE3)(pLysS) | F ompT hasdSB (rB− mB−) gal dcm (DE3) pLysS (Cmr) | Novagen |
| Sinorhizobium meliloti strains | ||
| RCR2011 | SU47, wild type | 30 |
| 1021 | Derivative of RCR2011, Strr | 20 |
| GM1211 | Derivative of RCR2011, Strr Lac | 23 |
| 5000 | Derivative or RCR2011, Rifr | 8 |
| M1A | Rm5000 choX::Ω, Rifr Spr | This study |
| Plasmids | ||
| PLAFR3 | IncP cosmid cloning vector, Tcr | 10 |
| pRK600 | ColE1 replicon with RK2 transfer region, Cmr | 8 |
| pBluescriptSK(−) | Derivative of pUC19 with f1(−)oriR, Ampr | Stratagene |
| pGEM T-3Zf(+) | Cloning vector | Promega |
| pET20-b(+) | Derivative of pBR322, T7 promoter, 3′ His codons, Ampr | Novagen |
| pSUP202 | ColE1, Mob+ Tcr Ampr Cmr | 33 |
| pHP45-Ω | Apr, pBR322 derivative with interposon Ω Smr/Spr | 28 |
| pGQ5 | pGEMT vector with bup1-pro4-amplified fragment | This study |
| pF1 | pLAFR3 with an S. meliloti 16-kb insert containing cho locus | This study |
| p1.2E | 1.2-kb EcoRI fragment from pF1 cloned into pBSSK− vector | This study |
| p1.5E | 1.5-kb EcoRI fragment from pF1 cloned into pBSSK− vector | This study |
| p3.4HE | 3.4-kb HindIII-EcoRI fragment from pF1 cloned into pBSSK vector | This study |
| p6.5H | 6.5-kb HindIII fragment from pF1 cloned into pBSSK vector | This study |
| pSUP6.5H | 6.5-kb HindIII fragment from pF1 cloned into pSUP202 vector | This study |
| pXΩ | pSUP6.5H, choX::Ω (BglII insertion) | This study |
| pETNE | pET20b, Nde1-EcoRI fragment (choX without His codon fusion) | This study |
| pETNX | pET20b, Nde1-Xho1 fragment (choX with 3′ His codon fusion) | This study |