Table 1.
Strains and plasmids used in this study. FRT, flippase recombinase recognition target.
| strain/plasmid | genotype/description | reference |
|---|---|---|
| strain | ||
| E. coli | ||
| TOP10 | cloning strain | Invitrogen |
| S. Typhimurium | ||
| JSG 210 | ATCC 14028s (WT) | [28] |
| RLK6 | JSG210ΔgudT::FRT (ΔgudT) | this study |
| RLK7 | JSG210ΔhycC::FRT (ΔhycC) | this study |
| TT22971 | methylating strain | John Roth |
| plasmids | ||
| pCP20 | Ampr; contains flippase gene for λ Red mutagenesis | [37] |
| pKD46 | Ampr; contains λ Red genes γ, β and exo | [37] |
| pKD4 | Kanr; contains kan cassette | [37] |
| pLac22 | Ampr; complementation vector (E. coli Plac) | [38] |
| pLac22-gudT | pLac22 with gudT (BglII-SalI) under Plac control | this study |