Table 1. Bacterial strains and plasmids used in this study.

Strain or plasmid	Relevant characteristic	Reference or Source
E. coli
XL1-Blue MRF’	Δ(mcrA)183 Δ(mcrCB-hsdSMR-mrr)173 endA1 supE44 thi-1 recA1 gyrA96 relA1lac[F′ proABlacI qZ ΔM15 Tn10 (Tetr)]	Stratagene
SM10	λpir	R. Calendar
L. monocytogenes
10403S	wild type, StmR	D. Portnoy
EGDe	wild type	J. Kreft
EGDe ΔprfA	prfA deleted	J. Kreft [24]
LF001	10403S derivative, tRNAArg::Prha gfp	This work
LF002	10403S derivative, tRNAArg::Prha ermC	This work
LF003	10403S derivative, tRNAArg::pPL3	This work
LF004	10403S derivative, tRNAArg::gfp	This work
LF005	10403S derivative, tRNAArg::Phyp gfp	This work
LF006	EGDe ΔprfA, tRNAArg::Prha prfA	This work
Plasmids
pPL2	cat cat; E. coli / L. monocytogenes shuttle vector; thermosensitive ori for Listeria	[34]
pPL3e	pPL2 derivative, cat ermC gfp; E. coli / L. monocytogenes shuttle vector;thermosensitive ori for Listeria	D. Higgins [35]
pLF1	pPL2 derivative, Prha	This work
pLF2	pPL2 derivative, Prha gfp	This work
pLF3	pPL2 derivative, Prha ermC	This work
pLF4	pPL2 derivative, gfp	This work
pLF5	pPL2 derivative, Phyp gfp	D. Higgins
pLF6	pPL2 derivative, Prha prfA	This work
pLEB599	Source of ermC	T. Takala