TABLE 1.

L. monocytogenes and E. coli strains used in this study

StrainDescriptionAssociated designationReference(s) or source
DH5αE. coli strain for constructing recombinant plasmids
SM10E. coli strain as conjugation donor for pPL2 plasmid
NF-L10010403S wild type3,18
DP-L216110403S Δhlyhly36
DP-L390310403S with Tn917 insertion1
NF-L1003NF-L890 (ΔprfA) with actA-gus-plcB transcriptional fusion72
NF-E1019E. coli DH5α with pPL2-PplcA-prfA72
prfA mutants
    NF-L1009NF-L1003 tRNAArg::pPL2 (ΔprfA plus pPL2i)aΔprfA72
    NF-L1011NF-L1003 tRNAArg::pPL2-prfA(L140F) (ΔprfA plus L140Fi)prfA(L140F)72
    NF-L1041NF-L1003 tRNAArg::pPL2-prfA476prfA plus WTi)Wild-type prfA72
    NF-L1185NF-L1003 tRNAArg::pPL2-prfA(E77K) (ΔprfA plus E77Ki)prfA(E77K)This work
    NF-L1186NF-L1003 tRNAArg::pPL2-prfA(G155S) (ΔprfA plus G155Si)prfA(G155S)This work
    NF-L1226NF-L1003 tRNAArg::pPL2-prfA(G145S) (ΔprfA plus G145Si)prfA(G145S)This work
Insertion mutants
    NF-L1239NF-L100 with pKSV7 single-crossover insertion within actAactAibThis work
    NF-L1240NF-L100 with pKSV7 single-crossover insertion within lmo0135lmo0135iThis work
    NF-L1241NF-L100 with pKSV7 single-crossover insertion within tcsAtcsAiThis work
    NF-L1242NF-L100 with pKSV7 single-crossover insertion within lmo2219lmo2219iThis work
    NF-L1243NF-L100 with pKSV7 single-crossover insertion within lmo2417lmo2417iThis work
    NF-L1245NF-L100 with pKSV7 single-crossover insertion near but not in lmo2219Silent pKSV7 insertionThis work
ΔflaA mutant
    NF-L1246NF-L965 tRNAArg::pPL2 (ΔflaA plus pPL2i)ΔflaAThis work
  • a i, pPL2 plasmid insertion.

  • b i, pKSV7 plasmid insertion in designated ORF.