Table 1.

Y. pestis strains and plasmids used in this study

Strain or plasmid	Descriptiona	Source or reference
Strains
KIM6+	Tc genes present, pCD1 negative, pgm positive, pPCP1 positive	51
KIM6	Tc genes present, pCD1 negative, pgm negative, pPCP1 positive	51
KIM10	Tc genes present, pCD1 negative, pgm negative, pPCP1 negative	9
KIM5	Tc genes present, pCD1 positive, pgm negative, pPCP1 positive	52
KIM6+ ΔyitA-yipB	Deletion of the Tc locus from yitA to yipB, yitR still present	8
KIM6+ ΔyitR	Deletion of the regulator YitR	7
KIM6+ YitA–β-lactamase	YitA::β-lactamase translational fusion	8
KIM6+ YipA–β-lactamase	YipA::β-lactamase translational fusion	8
KIM5 YitA–β-lactamase	YitA::β-lactamase translational fusion	8
KIM5 YipA–β-lactamase	YipA::β-lactamase translational fusion	8
KIM6 YitA–β-lactamase	YitA::β-lactamase translational fusion	8
KIM6 YipA–β-lactamase	YipA::β-lactamase translational fusion	8
Plasmids
pCR-XL-TOPO::yitR	yitR expressed under native promoter control from a high-copy-number plasmid (Kan, Zeo)	8
pUC19::yitR	yitR expressed under native promoter control from a high-copy-number plasmid (Amp)	This study
pWKS130::yitR	yitR expressed under native promoter control from a low-copy-number plasmid (Kan)	7
pCD1Δ1234	Plasmid encoding the genes required for the T3SS, with no effector Yops (Cam)	18
pCD1::kan	pCD1ΔyadA::kan (Kan)	53
pMM83	Plasmid pHSG576 encoding YopM–β-lactamase under control of its native promoter (Cam)	32
pMM85	Plasmid pHSG576 encoding YopE–β-lactamase under control of its native promoter (Cam)	32
pAcGFP1	Constitutively produces GFP (Amp)	Clontech
pmCherry	Constitutively expresses mCherry (Amp)	Clontech

^aAntibiotic resistances, where present, are noted in parentheses. Kan, kanamycin; Amp, ampicillin; Cam, chloramphenicol; Zeo, zeocin.