TABLE 1.

Bacterial strains and plasmids used in this study

Strain or plasmid	Genotype or descriptiona	Source or reference
E. coli NM522	Δ(lac-proAB) thi hsd-5 supE [F′ proAB+ lacIqlacZΔM15]	Stratagene
E. chrysanthemi
EC16	Wild-type strain	A. Chatterjee, University of Missouri
3937	Wild-type strain isolated from Saintpaulia ionanthia	Laboratory collection
A350	lmrT(Con) lacZ2	Laboratory collection
A1510	A350, kdgK arg10 pelD::lacZ Cmr	Laboratory collection
A837	A350, kdgR	Laboratory collection
A2011	A350, pecS::uidA Kanr	Laboratory collection
A2348	A837, pecS::uidA Kanr	Laboratory collection
A3485	A350, pelD::lacZ Cmr	This work
A3486	A2011, pelD::lacZ Cmr	This work
A3487	A837, pelD::lacZ Cmr	This work
A3489	A2348, pelD::lacZ Cmr	This work
Plasmids
pUC18	Cloning plasmid	31
pBluescript	Apr, lacZ′	Stratagene
pSR2159	pUC18 with the 495-bp BstEII-HpaI fragment containing the pelA regulatory region from strain 3937 inserted between the SmaI and XbaI sites	19
pN1272	pBluescript with 725-bp HindIII-BglII fragment contained the pelD regulatory region from strain 3937 inserted into the HindIII-BamHI sites	N. Hugouvieux-Cotte-Pattat
pWN2481	pBluescript with 318-bp HpaI-HindIII fragment contained the pelD regulatory region from strain 3937 inserted into the EcoRV-HindIII sites	This work
pPEL743	pUC18 carrying pelE gene from strain EC16 and 5′ sequences	29
pElux781	Oligonucleotide mutant in which bases 34 to 37 (AAAC) of the EC16 pelE promoter were deleted:ΔOP2	12
pElux782	Oligonucleotide mutant in which bases 19 to 22 (ATTT) of the EC16 pelE promoter were deleted:ΔOP1	12
pElux783	Oligonucleotide mutant in which bases −41 to −43 (TGA) of the EC16 pelE promoter were deleted: ΔCRP1	12
pElux784	Oligonucleotide mutant in which the deletions in both pElux781 and pElux782 were introduced into the EC16 pelE promoter: ΔOP1 + OP2	12

^aGenotype designations are according to reference 2. lmrT(Con) indicates that the transport system encoded by the gene lmrT, which mediates entry of lactose, melibiose, and raffinose into cells, is constitutively expressed. lacZ′ indicates that the 3′ end of the lacZ gene is truncated.