Table 1 Bacterial strains and plasmids used in this study.

Strains

P. fluorescens ST

Sty⁺

[39]

E. coli DH5α

endA1 hsdR17 supE44 thi-1 recA1 gyrA96 (Nal^R) relA1 Δ (lacIZYA-argF)U169 deoR(Φ80dlacZ ΔM15)

Bethesda Res. Lab.

Plasmids

pBluescript II KS+

Cloning vector; Ap^R; 2.9 Kb.

Stratagene

pPR9TT

lacZ promoter probe vector; Ap^R; Cm^R.

[40]

pTE50

pTZ19R derivative containing a P. fluorescens ST chromosomal fragment carrying the genes coding for styR, styA and styB; Ap^R.

[7]

pRK2013

Helper plasmid; ColE1 replicon; Mob+; Tra+; Km^R.

[37]

pSTY1/2

155 bp fragment, encompassing nucleotides -145 to -8, with respect to the styA transcription start point ligated to the Eco RI-Pst I sites of pBluescript II KS+; Ap^R.

[16]

pPR9Pa1

355 bp fragment, encompassing nucleotides -115 to +240, with respect to the styA transcription start point, ligated to the Xho I-Bam HI sites of pPR9TT; Ap^R; Cm^R.

[20]

pPR9STY1mut

Same construct as pPR9Pa1, but the cloned sequence carries a double mutation in positions -97 and -96 from the styA trascription start point; Ap^R; Cm^R.

This study

pPR9IHFmut

Same construct as pPR9Pa1, but the cloned sequence carries a double mutation in positions -101 and -91 from the styA trascription start point; Ap^R; Cm^R.

This study