TABLE 1.
Bacterial strains useda
| Strain | Genotype | Source or reference |
|---|---|---|
| MC4100 | λ− e14− araD139 Δ(arg-lac)169 flhD5301 deoC1 relA1 rbsR22 rpsL150 Δ(fruK-yeiR) Δ(fimB-fimE)632 | Lab stock (49) |
| LAA32 | MC4100 ΔnagB::cat-sacB | 19 |
| LAA193 | MC4100 gamA | This study |
| LAA195 | MC4100 nagBBs | This study |
| LAA199 | MC4100 | Wild-type recombinant |
| MC-B1 | MC4100 λRS/nagB-lacZ | 34 |
| MC-B52 | MC-B1 ΔnagEBACD::Tc | 34 |
| MC-B76c | MC-B1 ΔnagB | This study |
| MC-B174c | MC-B1 ΔnagA | 34 |
| MC-B362 | MC-B1 gamA | This study |
| MC-B364 | MC-B1 nagBBs | This study |
| BL21*ΔnagEBACD/pRARE | ompT hsdS gal dcm rne131 (DE3) ΔnagEBACD::Tc/pRARE | This study |
a
MC-B76c carries the ΔnagB::FRT kanamycin mutation from the Keio collection (50) and was then cured of the kanamycin cassette by transformation with pCP20 (33). The ΔnagA mutation in MC-B174c removes only the 5′ half of the nagA gene, leaving the nagC promoters intact (34). ΔnagEBACD::Tc was introduced into BL21* (51) [previously called BL21(DE3) (rne131)] by P1 transduction, and the resulting strain was transformed with the pRARE plasmid from Rosetta(DE3) (Novagen).