TABLE 1.
Strains and plasmids used in this study
| Strain or plasmid | Reference(s) or source | Description |
|---|---|---|
| Strains | ||
| S. aureus | ||
| RN6390 | 22, 26 | Laboratory strain that maintains its hemolytic pattern when propagated on sheep erythrocytes and has a genetic background similar to that of 8325-4 |
| RN4220 | 26 | Mutant of 8325-4 that accepts foreign DNA |
| COL | 30 | Methicillin-resistant S. aureus strain |
| RUSA168 | 30 | sigB mutant of COL (sigB::Tn551) |
| ALC1001 | This study | sigB mutant of RN6390 |
| ALC1497 | This study | ALC1001 complemented with shuttle plasmid pALC1496 (with the sigB gene) |
| E. coli | ||
| BL21 | Novagen | Host strain for pET14b |
| DU5384 | 27 | Host strain carrying pBR322 with a 3-kb EcoRI-HindIII fragment of the hla gene |
| Plasmids | ||
| pCR2.1 | Invitrogen | PCR cloning vector |
| pET14b | Novagen | E. coli expression vector |
| pALC103 | 3 | pSPT181 with a sar fragment from nucleotides 620 to 1349 |
| pALC1270 | This study | pET14b with the sigB coding region cloned into the NdeI-BamHI sites |
| pDG148 | 18 | B. subtilis-E. coli shuttle plasmid (8.2 kb) containing the pSpac promoter (IPTG inducible) followed by a polylinker site and lacI |
| pSK236 | 19 | S. aureus-E. coli shuttle vector with pUC19 cloned into the HindIII site of pC194 |
| pALC1456 | This study | pSK236 containing a 1.6-kb fragment derived from pDG148 and comprising, sequentially, the pSpac promoter, a polylinker site, and the lacI repressor |
| pALC1496 | This study | pALC1456 with the sigB gene (rbs + coding region) cloned into the polylinker site (SalI-PstI) derived from pDG148 |