TABLE 1.

Bacterial strains and plasmids used in this study

Strain or plasmidRelevant characteristicsaSource or reference
Strains
    L. plantarum 965Strain sensitive to sakacin 23K9
    L. sakei Lb790(pSAK20)Host strain for sakacin A (sap)-based expression system; carries pSAK204, 41
Plasmids
    pSAK20Camr; contains all genes necessary for transcriptional activation and processing of peptides with sap leader4
    pLPV111Eryr; expression vector4
    pLG101pLPV111 derivative containing genes for sakacin A (sapA) and sakacin A immunity (saiA) behind the sapA promoter11
    pSkkαpLPV111 derivative containing genes for Skkα with sapA leader and for SkkI, behind the sap promoterThis study
    pSkkβpLPV111 derivative containing genes for Skkβ with sapA leader and for SkkI, behind the sap promoterThis study
    pMG36eEryr; expression vector containing P32 promoter48
    pSkkIpMG36e with skkI cloned downstream of P32This study
    pSkkIE133A E135ApSkkI with E133A E135A double mutationThis study
    pSkkIE133Q E134QpSkkI with E133Q E134Q double mutationThis study
    pSkkIH214DpSkkI with H214D mutationThis study
    pPlnIpMG36e with plnI cloned downstream of P32This study
    pPlnLRpMG36e with plnLR cloned downstream of P32This study
  • a Camr, chloramphenicol resistance; Eryr, erythromycin resistance.