TABLE 1.
Bacterial strains and plasmids used in this study
| Strain or plasmid | Relevant characteristicsa | Source or reference |
|---|---|---|
| Strains | ||
| E. coli | ||
| DH5α | F− supE44 lacA-U169 ϕ80lacZΔM15 hsdR17 recA1 endA1 gyrA96 thi-1 relA1 | Transgen |
| RP437 | thr(Am)-1 leuB6 his-4 metF(Am)159 eda-50 rpsL136 [thi-1 ara-14 lacY1 mtl-1 xyl-5 tonA31 tsx-78]b | 37 |
| UU2685 | (cheZ)Δ4211 thr(Am)-1 leuB6 his-4 metF(Am)159 rpsL136 [thi-1 ara-14 lacY1 mtl-1 xyl-5 tonA31 tsx-78] | 38 |
| UU2685CheZ | UU2685 derivative, contains pBBRCheZ; Kmr | This study |
| Azorhizobium caulinodans | ||
| ORS571 | Type strain; Ampr, Nalr | 24 |
| AC601 | ORS571 derivative, ΔcheZ; Ampr, Nalr, Gmr | This study |
| AC602 | AC601 derivative, contains pBBRCheZ; Kmr, Ampr, Nalr, Gmr | This study |
| AC603 | AC601 derivative, contains the mutated plasmid pBBRCheZD150A; Ampr, Nalr, Gmr, Kmr | This study |
| AC604 | AC601 derivative, contains the mutated plasmid pBBRCheZQ154A; Ampr, Nalr, Gmr, Kmr | This study |
| Plasmids | ||
| pCM351 | Allelic exchange vector; Gmr, Tcr | 61 |
| pRK2013 | Helper plasmid, ColE1 replicon; Tra+, Kmr | 62 |
| pBBR1MCS-2 | Broad-host-range plasmid; Kmr | 63 |
| pBBRCheZ | pBBR1MCS-2 with cheZ open reading frame and 406-bp upstream promoter region; Kmr | This study |
| pBBRCheZD150A | pBBRCheZ carrying D150A substitution | This study |
| pBBRCheZQ154A | pBBRCheZ carrying Q154A substitution | This study |
a
Ampr, ampicillin resistance; Gmr, gentamicin resistance; Kmr, kanamycin resistance; Nalr, nalidixic acid resistance; Tcr, tetracycline resistance.
b
thr(Am)-1 and metF(Am)159 are amber (UAG) nonsense mutations in genes that cause auxotrophic requirements for the amino acids threonine and methionine, respectively. Other genetic markers are listed in the brackets.