Table 1.
Strains and plasmids used in this study
| Strain or plasmid | Relevant characteristics or use | Reference or source |
|---|---|---|
| C. diphtheriae strains | ||
| 1737 | Wild type, Gravis biotype, Tox+ | 37 |
| 1737htaAΔ | htaA deletion mutant of 1737 | 25 |
| 1737htaBΔ | htaB deletion mutant of 1737 | 25 |
| 1737chtAΔ | chtA deletion mutant of 1737 | This study |
| 1737chtBΔ | chtB deletion mutant of 1737 | This study |
| 1737chtCΔ | chtC deletion mutant of 1737 | This study |
| 1737chtAΔ/chtBΔ | Deletion of chtA and chtB in 1737 | This study |
| 1737htaBΔ/chtBΔ | Deletion of htaB and chtB in 1737 | This study |
| 1737chtAΔ/chtCΔ/htaAΔ | Deletion of chtA, chtC, and htaA in 1737 | This study |
| 1737chtAΔ/chtCΔ | Deletion of chtA and chtC in 1737 | This study |
| C7(−) | Wild type, Tox− | 38 |
| C7dtxRΔ | C7 dtxR deletion mutant | 25 |
| E. coli strains | ||
| BL21(DE3) | Protein expression | Novagen |
| DH5α | Cloning strain | Invitrogen |
| S17-1 | RP4 mobilization functions | 32 |
| TOP10 | Cloning of PCR fragments | Invitrogen |
| XL1-Gold | Mutagenesis strain | Stratagene |
| Plasmids | ||
| pCR-Blunt-IITOPO | Cloning of PCR fragments, Knr | Invitrogen |
| pSPZ | Promoter probe, Spcr | 28 |
| pGEX-6P-1 | Expression vector (GST fusion), Ampr | GE Healthcare |
| pET24(a)+ | Expression vector, Knr | Millipore |
| pKN2.6Z | C. diphtheriae shuttle vector, Knr | 24 |
| pKhtaA | pKN2.6Z carrying the htaA gene | 25 |