TABLE 1.

Strains and plasmid construction

Strain or plasmid	Genetic description	Source
E. coli strains
DH5α	F- Φ80lacZΔM15Δ (lacZYA-argF) U169 recA1	Invitrogen
BL21(DE3)	ΔompT gal dcm lon hsdSB (rB− mB−)λ (DE3)	(50)
A38a	C600 lepB (N274K)	(5)
AD202	ompT1000::kan, KmR	(51)
Plasmids
E. coli
pLEPB1-wt	pET23 (tag-His6)lepB, AmpR	(32)
pLEPB(N274K)	pET23 (tag-His6)lepB (N274K), AmpR	(9)
pLEPB1-mutb	pET23 (tag-His6)lepB(mutb), AmpR	This work
pColD1c	pUC18 cda-cdi-cdl, (EcoRI and BamHI), AmpR	(52)
pColDIc	pET11a cda-cdi(tag-His6), (NdeI/BamHI), AmpR	(9)
pColDI-mutc,d	pET11a cda(mutd)-cdi(tag-His6), (NdeI/BamHI), AmpR	This work
pColDI(H611A)c	pET11a cda-cdi(H611A; tag-His6), (NdeI/BamHI), AmpR	This work
pColD-CD(Glu-314--Met-590)	pET11a cda (tag-H6)Glu-314--Met-590, (NdeI/BamHI), AmpR	(9)
pColD-A(Glu-314--Leu-697)	pET11a cda(Glu-314--Leu-697)-cdi(tag-His6), (NdeI/BamHI), AmpR	This work
pColD-B(Met-1--Met-590)	pET11a cda (tag-His6)Met-1--Met-590, (NdeI/BamHI), AmpR	This work
pColD-E(Met-1--Met-590)	pACYC-Duet1 cda Met-1--Met-590, (NdeI/BglII), CmR	This work
pColD-Del(1–14)	pET11c truncated cda(tag-His6), (NdeI/BamHI), AmpR	This work
K. pneumoniae
pMC04-KlebC2e	pBSK+ kcp-kca-kci (BamHI), AmpR	(31)
pKlebCI	pACYC-Duet1 kca-kci(tag-His6), (NdeI/BglII), CmR	This work
K. oxytoca
pKlebDf	pBSK+ kdp-kda-kdi, (EcoRI), AmpR	(31)

^a Strain sensitive to pore-forming colicin B but resistant to tRNase colicin D.

^b Mutations in LepB: N274A, N274D, N277A, N277K, G272A, or A279G.

^c cda and cdi are genes encoding colicin D and its immunity protein; cdl encodes the bacteriocin-release protein.

^d Mutations in colicin D: G413A, A422D, A422V, G423D, S426A, P430A, G431D, G431A, R432A.

^e kca and kci are genes encoding klebicin C and its immunity protein; kcp and kdp are genes for phage tail fiber-like proteins in Klebsiella strains.

^f kda and kdi are genes encoding klebicin D and its immunity protein.