TABLE 1.

Bacterial strains and plasmids

Strain or plasmidRelevant characteristic(s)aReference or source
Strains
    S. meliloti
        Rm1021SU47 str-21 Smr35
        Rm2011SU47 str-3 Smr11
        Rm5000SU47 rif-5 Rifr19
        SRmA363Rm1021 expR+38
        SRmA938Rm1021 pKnock-Gm containing 5′ nptII::3′ flanking tatABCThis work
        SRmA946Rm1021 pRK7813tatABC::pKnock-GmThis work
        SRmA947Rm1021 tatABCΔ/pRK7813tatABCThis work
    S. medicae
        SmD100WSM419 SmrThis work
        SmD104SmD100(pBP92)This work
        SmD107SmD107(pBP93)This work
    E. coli
        DH5αλ φlacZDM15 D(lacZYA-argF)U169 recA1 endA hsdR17(rK mK) supE44 thi-1 gyrA relA124
        S17-1recA derivative of MM294A with integrated RP4-2 (Tc::Mu::Km::Tn7)58
        MM294Apro-82 thi-1 hsdR17 supE4420
        MT607MM294A recA5620
        MT616MT607(pRK600)20
Plasmids
    pEX18TcBroad-host-range gene replacement vector; sacB Tcr26
    pBlueScript II SKCloning vector; ColE1 oriV AprStratagene
    pRK600pRK2013 npt::Tn9 Cmr20
    pRK7813RK2 derivative carrying pUC9 polylinker and lambda cos site; Tcr27
    pKnock-GmSuicide vector for insertional mutagenesis; R6K ori RP4 oriT Gmr2
    pPH1JIIncP plasmid; Gmr7
    pBP59sacB from pEX18Tc inserted into pRK7813This work
    pBP79pBP59 with tatABC cloned into polylinkerThis work
    pBP91pRK7813 tatC::nptII; oriented in the same direction as PlacThis work
    pBP92pRK7813 tatC::nptII; oriented in the opposite direction as PlacThis work
    pBP103pKnock-Gm containing upstream 5′ tatABC fragmentThis work
    pBP105pBP103containing 3′ downstream tatABC fragmentThis work
    pBP121pBP105 containing nptII cassetteThis work
    pMM4tatC fragment cloned into pBSThis work
    pMM13Kanr fragment from pMM22 cloned into pMM4This work
    pMM22Kanr fragment cloned as a SmaI fragment into pBlueScriptThis work
  • a Cm, chloramphenicol; Gm, gentamicin; Kan, kanamycin; Nm, neomycin; Ap, ampicillin; Sm, streptomycin.