TABLE 1.
Bacterial strains and plasmids used in this study
| Strain or plasmid | Relevant characteristic(s)a | Source or reference |
|---|---|---|
| Strains | ||
| S. mutans UA159 | Wild-type reference strain | Laboratory stock |
| E. coli DH10B | Host strain for cloning and plasmid production | Laboratory stock |
| E. coli LMG194 | Host strain for pBAD expression | Invitrogen |
| E. coli XL10-Gold | Host strain for site-directed mutagenesis | Agilent Technologies |
| ΔlexA mutant | In-frame SMU.2027 deletion mutant derived from S. mutans UA159; Spr | This study |
| UA159(pIB184) | UA159 harboring pIB184; Emr | This study |
| ΔlexA::lexA A115D mutant | ΔlexA mutant harboring pVL6 chromosomally integrated; Spr Kmr | This study |
| ΔlexA(pVL2) mutant | ΔlexA mutant harboring pVL2; Spr Emr | This study |
| ΔlexA(pVL3) mutant | ΔlexA mutant harboring pVL3; Spr Emr | This study |
| LMG194(pVL4) | LMG194 containing pVL4; Kmr | This study |
| LMG194(pVL5) | LMG194 containing pVL5; Kmr | This study |
| ΔumuC mutant | In-frame SMU.403 deletion mutant derived from S. mutans UA159; Emr | This study |
| ΔclpP mutant | In-frame SMU.1672 deletion mutant derived from S. mutans UA159; Emr | This study |
| ΔcomE mutant | In-frame SMU.1917 deletion mutant derived from S. mutans UA159; Emr | 25 |
| ΔcipB mutant | In-frame SMU.1914 deletion mutant derived from S. mutans UA159; Emr | 25 |
| ΔcomS mutant | In-frame comS deletion mutant derived from S. mutans UA159; Emr | This study |
| ΔcomR mutant | In-frame SMU.61 deletion mutant derived from S. mutans UA159; Emr | D. Morrison, UICb |
| ΔsigX mutant | In-frame SMU.1997 deletion mutant derived from S. mutans UA159; Emr | 25 |
| ΔscrA mutant | In-frame SMU.1841 deletion mutant derived from S. mutans UA159; Emr | This study |
| Δcsn2 mutant | In-frame SMU.1402 deletion mutant derived from S. mutans UA159; Emr | This study |
| Δ63 mutant | In-frame SMU.63 deletion mutant derived from S. mutans UA159; Emr | This study |
| Δ984 mutant | In-frame SMU.984 deletion mutant derived from S. mutans UA159; Spr | This study |
| Plasmids | ||
| pBAD202/D-TOPO | Expression vector linearized and topoisomerase activated; Kmr | Invitrogen |
| pIB184 | Shuttle plasmid containing the constitutive P23 lactococcal promoter; Emr | 35 |
| pIB107 | Plasmid for chromosomal integration into S. mutans; Kmr | 35 |
| pVL2 | lexA cloned into pIB184 under the control of its own promoter; Emr | This study |
| pVL3 | lexA A115D mutation into pVL2; Emr | This study |
| pVL4 | lexA cloned under the control of the araBAD promoter into pBAD202/D-TOPO vector; Kmr | This study |
| pVL5 | lexA A115D mutation cloned under the control of the araBAD promoter into pBAD202/D-TOPO vector; Kmr | This study |
| pVL6 | lexA A115D mutation cloned under the control of its own promoter into pIB107; Kmr | This study |
a
Emr, erythromycin resistance; Kmr, kanamycin resistance; Spr, spectinomycin resistance.
b
UIC, University of Illinois at Chicago.