TABLE 2.
Strains, phages, and plasmids
| Bacterial strains, phages, or plasmids | Relevant characteristics and construction | Source or reference |
|---|---|---|
| E. coli strains | ||
| MC1061 | F−araD139 Δ(ara-leu)7696 galE15 galK16 Δ(lac)X74 rpsL (Strr) hsdR2 (rK− mK+) mcrA mcrB1 | 7 |
| BR7024 | λRDM12 in MC1061; used here as the repressor test strain | 37 |
| BR7021 | λRDM 11 (P phd+-lacZYA) placIQ in MC1061; parent of BR7061 | 38 |
| BR7061 | λRDM 11 placIQ pRDM082 (Ptac-doc+) in MC1061; used here as the antitoxin test strain | This work |
| Lambda phages | ||
| λRS45 | A lambda phage carrying a promoterless lacZYA | 54 |
| λRDM12 | P1 plasmid addiction promoter fused to lacZYA; derived from λRS45 | 37 |
| λRDM 11 | P phd+ fused to lacZYA; provides a low level of Phd; derived from λRS45 | 38 |
| Plasmids | ||
| placIQ | lacIq in pACYC177; p15A origin; Kanr; a source of Lac repressor | R. Kolodner |
| pKK223-2 | Ptac expression vector, pMB1 origin, Ampr | 6 |
| pRDM037 | Ptac-doc+ in pKK223-3 | 38 |
| pGB2 | Modest-copy-number cloning vector; pSC101 origin; Specr | 10 |
| pRDM082 | Ptac-doc+ from pRDM037 cloned between BamH1 and HindIII sites of pGB2 | This work |
| pGB2ts | A derivative of pGB2 whose replication is temperature sensitive | 11 |
| pG3 | P phd doc cloned into pGB2ts; used here as a PCR template | 33 |
| pBAD 24 | PBAD expression vector; pBR origin; Ampr | 22 |
| pJS004 | PBADphd+ (PCR of pG3 with JER074 and JER073 cloned into pBAD24) | This work |
| pJS005 | PBADphdΔ(2-17) (PCR of pG3 with JER075 and JER073 cloned into pBAD24) | This work |
| pJS006 | PBADphdΔ(2-35) (PCR of pG3 with JER076 and JER073 cloned into pBAD24) | This work |
| pJS007 | PBADphdΔ(2-53) (PCR of pG3 with JER077 and JER073 cloned into pBAD24) | This work |
| pJS001 | PBADphdΔ(19-73) (PCR of pG3 with JER074 and JER070 cloned into pBAD24) | This work |
| pJS002 | PBADphdΔ(37-73) (PCR of pG3 with JER074 and JER071 cloned into pBAD24) | This work |
| pJS003 | PBADphdΔ(55-73) (PCR of pG3 with JER074 and JER072 cloned into pBAD24) | This work |