TABLE 1.
Bacterial strains and plasmids
| Strain or plasmid | Relevant characteristic(s) | Source or reference |
|---|---|---|
| Strains | ||
| L. lactis | ||
| MG1363 | Plasmid-free derivative of NCD0712; Lac− Prot− | 5 |
| IM15 | MG1363 ΔpepX ΔpepT ΔpepC ΔpepN | 20 |
| AMP15 | MG1363 ΔoppA | This work |
| AMP2 | IM15 ΔoppA | This work |
| E. coli | ||
| BZ234 | C600 derivative; Ems | |
| Plasmids | ||
| pVS8 | Cmr; pSH71 replicon; opp operon of L. lactis | 37 |
| pORI280 | Emr; lacZ+; deletion derivative of pWV01 lacking repA | 16 |
| pAP2 | pORI280 containing the 5′ and 3′ flanking regions of oppA | This work |
| pSKII(+) | Carbr; high-copy-number expression vector | Stratagene |
| pSKE8His | pSKII(+)-derivative carrying lacS with NcoI site on the initiation codon and a C-terminal His tag | 10 |
| pGK13 | Emr Cmr; pWV01 replicon; E. coli-L. lactis shuttle vector | 11 |
| pGKGS8 | pGK13 derivative carrying lacS as a 3,784-bp EcoRI-DraI fragment from pSKE8His ligated into the EcoRI-EcoRV sites | 10 |
| pMG36e | P32 promoter of L. lactis subsp. cremoris Wg2; Emr | 38 |
| pAMP21 | pGK13 derivative with oppA as a 1,736-bp NcoI-BamHI fragment | This work |
| pAMP31 | pGK13 derivative with oppA as a 1,802-bp NcoI-BamHI fragment | This work |
| pAMP31(K349Q) | pAMP31 with Lys-349 of OppA-His6 replaced by Gln | This work |
| pAMP31(N422H) | pAMP31 with Asn-422 of OppA-His6 replaced by His | This work |
| pAMP31(A423H) | pAMP31 with Ala-423 of OppA-His6 replaced by His | This work |
| pAMP31(D471R) | pAMP31 with Asp-471 of OppA-His6 replaced by Arg | This work |
| pAMP31(A477D) | pAMP31 with Ala-477 of OppA-His6 replaced by Asp | This work |