TABLE 1.

Strains and plasmids used in this study.

Strains or plasmids	Relevant characteristics	Sources
Strains
E. coli W1688a	L-threonine producing strain	Prof. Sheng Yang
E. coli W1688-fimH*	E. coli W1688 harboring plasmid pET28a-fimH	This study
E. coli W1688-ΔfimH	E. coli W1688 with the deletion of fimH	This study
E. coli W1688-pKD46	E. coli W1688 harboring plasmid pKD46	This study
Plasmids
pET28a	Kan resistance	Stored in our lab
pET28a-fimH	pET28a containing fimH	This study
pKD46	Amp resistance	Stored in our lab
pKD4	Kan resistance	Stored in our lab

^aA gift from Prof. Sheng Yang (Institute of plant physiology and ecology, CAS, Shanghai, China).