TABLE 1.

E. coli strains used in this study

Strain name	Relevant genotype or property	Origin or reference
XL1-Blue	Standard cloning strain	Stratagene
HSK42	MC4100, polA	7
GT869	Standard cloning strain, K-12 derivative	Laboratory collection
HM0079	GT869 nrdD::sfp Spcr	This study
NK5525	proA81::Tn10	E. coli Genetic Stock Center
MG1655	Wild-type E. coli K-12	4
MG1655 (pro-81::Tn10)	MG1655 pro-81::Tn10	This study