TABLE 1.

Strains and plasmids used in this study

Strain or plasmidGenotype or general informationaSource or reference
Strains
    E. coli
        BL21(DE3)(λDE3) FompT hsdSB(rBmB) dcm galNovagen; 56
        SA1503(DE3)(λDE3) lon-100(del) his-87 ompT::KmrrelA1 rspL 181 spoT1 thi-1 24
        MG4Δ(argF-lac)U169 zah-735::Tn10 recA56srl::Tn10 47
    P. aeruginosa
        PAO1Wild-type P. aeruginosa PAO1
        PAO214In a wild-type P. aeruginosa PAO1 background; unmarked ΔlasI chromosomal deletion (EcoRI-PstI fragment, 187 bp) 25
Plasmids
    pKDT17a lasB::lacZ translational fusion and plac-lasR; Apr 52
    pEsaIEsaI coding region in pET14B; Apr 61
Expressed in E. coli BL21(DE3)
    pEsaI T140ASame as pEsaI, but with an Ala codon substitution at position 140 62
    pLasILasI coding region in pViet; Apr 24
Expressed in E. coli SA1503(DE3) 18
    pLasIΔGLasI coding region in pViet, with substitution of TPEA with a Gly codon 18
    pLasIΔG T142ApLasIΔG, with a codon substitution (T142A); mutagenic primer CGCCTACGGTGGTTACAGCCACCAGCGTCTGGATThis study
    pLasIΔG T142GpLasIΔG, with a codon substitution (T142S); mutagenic primer CGCCTACGGTGGTTACACCCACCAGCGTCTGGATThis study
    pLasIΔG T142SpLasIΔG, with a codon substitution (T142G); mutagenic primer CGCCTACGGTGGTTACAGACACCAGCGTCTGGATThis study
    pLasIΔG T144VpLasIΔG, with a codon substitution (T144V); mutagenic primer CTTCTCCACGCCTACGGTAACTACCGTCACCAGCGTCThis study
    pEX30-laspEX30 with LasIΔG (NdeI-HindIII fragment from LasIΔG in pViet); Apr 18, 54
  • a Codon substitutions are underlined.