TABLE 1.

Bacterial strains and plasmids

Strain or plasmid	Relevant characteristicsa	Reference or source
E. coli K-12
DH5α	Cloning host	Gibco-BRL
UT5600	Protease-deficient strain; ΔompT ΔompP; Smr	Laboratory stock
S. flexneri
2457T	S. flexneri 2a WT	53
RMA2041	2457T ΔicsA::Tcr	54
RMA2090	RMA2041(pIcsA)	54
RMA2043	RMA2041 ΔrmlD::Kmr	54
RMA2107	RMA2043(pIcsA)	54
Plasmids
pIcsA	icsA gene cloned into pBR322; Apr; medium copy no.; ColE1 ori	33
pD10	Plasmid encoding IcsAWT; Tpr	51
pD10-virG1	Plasmid encoding IcsAΔ103-320; Tpr	51
pD10-virG3	Plasmid encoding IcsAΔ508-730; Tpr	51
pD10-virG4	Plasmid encoding IcsAΔ103-507; Tpr	51

^aSm^r, streptomycin resistant; Tc^r, tetracyline resistant; Km^r, kanamycin resistant; Ap^r, ampicillin resistant; Tp^r, trimethroprim resistant.