Table 1.

Strains and plasmids used in this study

Strain or plasmidRelevant characteristicsSource or reference
V. cholerae
 92A1552El Tor, Inaba, wild type, Rifs Laboratory collection
 92A1552-Rifr El Tor, Inaba, wild type, Rifr This study
 FY192A1552-Rifr,rpoS::cm This study
 3083El Tor, Ogawa, wild type 18
 HAP-1El Tor, Ogawa, HA/protease-negative derivative of 3083 18
E. coli
 ZK918W3110 ΔlacU169 tna-2 rpoS::kan bolA::lacZ 6
 DH5αF′ endA1 hsdR17 supE44 thi-1 recA1 gyrA96 relA1 Δ(argF-lacZYA) U169(φ80dlacZΔM15)Laboratory collection
 S17-1 (λ pir)Tpr Smr recA thi pro rK mK + RP4:2-Tc:MuKm Tn7 λpir Laboratory collection
Plasmids
 pBluescriptKS+ Apr, ColE1, high-copy-number cloning vectorStratagene
 pGEM-7 ZF+ Apr Promega
 pUC19/18 (HEH)Apr tandem pUC19/18 multiple cloning siteLaboratory collection
 pHP45Ω-CmApr, Cmr, source of the catgene 12
 pKNG101Smr,oriR6K, mobRK2, sacB, suicide vector 44
 pMMB67EHApr, IncQ broad-host-range cloning vector 38
 pWKS130Kanr, low-copy-number cloning vectorLaboratory collection
 pFY1pBluescriptKS+ with 4-kb V. cholerae Sau3A fragment containing the complete coding sequence ofrpoS, 464 bp of nlpD, and 2,364 bp ofmutS This study
 pFY2pBluescriptKS+ with 1.698-kb XbaI fragment containing complete coding sequence of rpoS, 464 bp of nlpD, and 44 bp ofmutS This study
 pFY3pGEM-7 ZF+ with 1.698-kb XbaI fragment of pFY1This study
 pFY4pUC19/18 with 1-kb PCR-amplified rpoS coding regionThis study
 pFY5pFY4 with rpoS coding region interrupted with cm cassette (rpoS::cm)This study
 pFY6pKNG101 containingrpoS::cm at SalI siteThis study
 pFY7pMMB67EH containing 1.698-kbXbaI fragment of pFY1 in opposite orientation totac promoterThis study
 pFY8pBluescriptKS+ containing 4-kbEcoRI fragment spanning whole coding region ofnlpD and rpoS flanked with surE andmutS This study
 pFY9pWKS130 containing 4-kbEcoRI fragment spanning whole coding region ofnlpD and rpoS flanked with surE andmutS This study
 pFY10pBluescriptKS+containing 3-kb BamHI fragment spanning whole coding region of nlpD, its upstream region, and first 500 bp ofrpoS This study
 pDEB2pUC19 containing E. coli rpoS 6