TABLE 1.

Bacterial strains and plasmids used in this study

Strain or plasmidCharacteristicsSource or reference
E. coli strains
    DH5αGeneral cloning strain, allows blue-white screening during cloningGibco-BRL
    S17-1λpirStrain capable of mobilizing the suicide vector pK18mobsacB into R. sphaeroides, Smr15
    M15Protein expression hostQiagen
R. sphaeroides strains
    WS8NSpontaneous nalidixic acid-resistant mutant of wild-type WS823
    JPA187WS8N containing a gfp-mreB fusion in place of the genomic mreBThis study
Plasmids
    pUC19High-copy-number cloning vector, AprPharmacia
    pK18mobsacBAllelic exchange suicide vector, Kmr19
    pHP45ΩCarries the omega cartridge, Smr17
    pEGFP-N1GFP fusion vector, KmrClontech
    pQE80Ptac-based expression vector; introduces RGS(H)6 sequence at the N termini of expressed proteins; AprQiagen
    pREP4Plasmid carrying the lacI gene; compatible with pQE80; reduces leaky expression from the tac promoter of pQE80; KmrQiagen
    c125pLA2917 containing ca. 25 kb of R. sphaeroides DNA, Tcr22
    pPKS1Derivative of pK18mobsacB containing the region upstream of mreBThis study
    pPKS2Derivative of pK18mobsacB containing the regions upstream and downstream of mreBThis study
    pPKS2ΩDerivative of pPKS2 containing the omega cartridge from pHP45Ω between the regions upstream and downstream of mreBThis study
    pBS1Derivative of pK18mobsacB containing the region upstream of mreB and gfpThis study
    pBS2Derivative of pK18mobsacB containing the gfp-mreB fusion; the region upstream of mreB and gfp and the upstream region of mreBThis study
    pMLP1Derivative of pQE80 containing mreBThis study