Table 1. E. coli K-12 strains and plasmids used in this study.

Strain or plasmid	Genotype	Source
W3110	K-12 (F− λ−)	[36]
JLS9318	MC4100 gadC::Tn10	[31]
JLS1015	W3110 tolC732::kan (Keio JW5503)	This work
JLS1023	W3110 acrB747::kan (Keio JW0451)	This work
JLS1024	W3110 mdtB774::kan (Keio JW2060)	This work
JLS1025	W3110 mdtF769::kan (Keio JW3482)	This work
JLS1026	W3110 emrY776::kan (Keio JW2364)	This work
JLS1027	W3110 emrB767::kan (Keio JW2661)	This work
JLS1036	W3110 tolC732::kan pMX	This work
JLS1039	W3110 marR751::kan (Keio JW5248)	This work
JLS1048	W3110 tolC732::kan gadC::Tn10	This work
JLS1050	W3110 emrB767::frt mdtB774::kan	This work
MG1655	K-12	M. Wachi
MG1655T	MG1655 tolC::Tn10	This work
N7829	K-12; GC4458	J.L. Rosner
M5567	N7829 tolC732::kan	J.L. Rosner
M6293	N7829 acrB747::frt acrD790::frt emrB767::frt emrY776::frt macB780::frt mdtC775::frt mdtF769::frt acrEF::spc	J.L. Rosner
JLS1042	M6293 tolC732::kan	This work
Plasmids
pMX	pMW119 carrying the tolC gene	[41]
pQEgadE	pQE80L carrying the gadE gene	[44]
pMF565	pQE80L [gadBC]his-gadB ApR	J.W. Foster