Table 1.

Bacterial strains and plasmids used in the study

Strain or plasmidRelevant genotype or phenotypeSource or reference
V. cholerae
 O395Smr Laboratory collection
 O395K1O395 dnaK::pGP704 Smr This study
 569BWild typeLaboratory collection
 JJM43ΔtoxR 16
E. coli
 CG800 dnaK103 thr::Tn10 41
 GW4813ΔdnaK 31
 CG2682C600 dnaJ259 thr::Tn10 38
 K165 rpoH(Am) 7
 pACYC177Cloning vector, AprKnr Laboratory collection
 pACYC184Cloning vector, Tcr Cmr Laboratory collection
 pSC350pACYC177 derivative with 3.5-kb HindIII fragment carrying 5′ part of V. cholerae dnaK geneThis study
 pSC510pACYC184 derivative with 5.1-kb NcoI fragment carrying 3′ part of V. cholerae dnaK geneThis study
 pSC830pACYC177 derivative with 8.3-kb fragment carrying entire V. cholerae dnaK and dnaJ genesThis study
 pUC18/19Cloning vector, Apr Boehringer Mannheim
 pKK232.8Promoter probe vector carrying a MCS at 5′ end of promoterless cat genePharmacia
 pSChspKK232.8 derivative with 550-bpEcoRI-HincII fragment of pSC350 carryingdnaK heat shock promoterThis study
 pNS1220-bpBamHI-EcoRV fragment of pVM7 carryinghtpG-toxR intergenic region cloned atBamHI-HindIII site of pKK232.8This study
 pNS2220-bp EcoRV-BamHI fragment of pVM7 cloned at SmaI-SalI site of pKK232.8This study
 pTAC3734Promoter probe vector with MCS inserted between promoterless lacZ and phoA genesN. C. Mandal, Bose Institute, Calcutta, India
 pSCGRpTAC3734 derivative with 220-bp BamHI-EcoRV fragment of pVM7 inserted at BamHI-StuI siteThis study
 pKP31 dnaK gene of E. coli in pBR322 31
 pVM7 toxR gene ofV. cholerae in pBR322 27
 pSC18.1 tcpA gene of V. cholerae in pTZ18U 39
 pCVD15 ctxAB genes of V. cholerae in pBR325 18
 pGP704 oriR6K mobRP4Apr 28