TABLE 1.
Characteristics of the strains used in this study
| Strain, phage, or plasmid | Relevant genotype | Source or reference |
|---|---|---|
| Strains | ||
| Rhizobium meliloti | ||
| Rm1021 | Wild type | 22 |
| DsAux7 | Cysteine auxotroph, Tn5-233 | J. Glazebrook and G. Walker |
| JSS27 | nodPQ1 and nodPQ2 deletion | 35 |
| MW26 | cysDRm::Tn5 transduced into JSS27 | This study |
| Escherichia coli | ||
| XL1-Blue | Wild type | Stratagene |
| JM96 | cysH56 | E. coli Genetic Stock Center |
| JM226 | cysH57 | E. coli Genetic Stock Center |
| CAG12182 | cysC3152::Tn10kan | E. coli Genetic Stock Center |
| Rhizobium leguminosarum 8401/pRL1 | Wild type | J. A. Downie |
| Rhizobium sp. strain NGR234 | Wild type | W. Broughton |
| Rhizobium fredii USDA257 | Wild type | S. Pueppke |
| Agrobacterium tumefaciens A136 | Wild type | 42 |
| λ clones | ||
| λ2-3 | λ clone containing Tn5-233 insertion of DsAux7 | This study |
| λ211 | λ clone containing wild-type DNA corresponding to the DsAux7 insertion site | This study |
| Plasmids | ||
| pALTER | Tcr site-directed mutagenesis vector | Promega |
| pQE-30 | Apr, 6-histidine protein-tagging and expression vector | Qiagen |
| pBluescript SK+/− | Apr ColE1, cloning vector | Stratagene |
| pSW213 | Tcr IncP, broad-host-range vector | S. C. Winans |
| pMW121 | pBluescript carrying one Tn5-233 end plus surrounding genomic DNA from λ2-3 | This study |
| pMW122 | Same as pMW121, but carrying the opposite Tn5-233 end | This study |
| pMW126 | pSW213 carrying an 8-kb BamHI fragment of R. meliloti DNA encoding all of cysN and part of cysD | This study |
| pMW163 | pBluescript carrying a 6-kb PstI-XhoI fragment containing the full-length R. meliloti cysHDN gene | This study |
| pMW179 | pALTER carrying a 4.3-kb HindIII fragment containing nodPQ2 | This study |
| pMW179-Kpn | pMW179 with a KpnI site introduced at the translation start site of nodQ2 | This study |
| pMW183 | pQE-30 carrying the KpnI-HindIII fragment of pMW179-Kpn containing nodPQ2 | This study |
| pProEX-1 | Apr, 6-histidine protein-tagging and expression vector | Gibco BRL |
| pPIA8 | pProEx-1 carrying the R. meliloti cysH gene | This study |