TABLE 1.
Bacterial strains and plasmids used in this study
| Strain or plasmid | Relevant characteristics | Reference or source |
|---|---|---|
| E. coli strains | ||
| BL21(DE3) | gal (λcIts857 ind1 Sam7 nin5 lacUV5-T7 gene 1) | Novagen |
| DH5α | supE44 ΔlacU169 (φ80 lacZΔM15) | BRL |
| XL1-Blue | relA1 lac [F′ proAB lacIqZ ΔM15 Tn10 (Tetr)] | Stratagene |
| S. pneumoniae strains | ||
| CP1200 | Nonencapsulated derivative of Rx1, malM511 str-1 | Choi et al.(8) |
| HYK1 | CP1200, ΔclpL::ermB | This study |
| HYK2 | CP1200, ΔclpP::ermB | This study |
| D39 | Encapsulated, type 2 | Avery et al. (1) |
| HYK302 | D39, ΔclpP::ermB | This study |
| HYK304 | D39, ΔclpL::ermB | This study |
| Plasmids | ||
| pET30(a) | 5.4 kb, Kmr | Novagen |
| pBluescript | 3.0 kb, Apr | Stratagene |
| pGEM-T | 3.0 kb, Apr, TA cloning vector | Promega |
| pG8413 | 1.3 kb, clpL PCR fragment in pBluescript | This study |
| pKHY004 | 7.5 kb, histidine-tagged clpL in pET30(a) | This study |