Table 1.

List of bacterial strains/phages and plasmids used in this study

Strain	Relevant genotype	Source/reference/construction
SG20780	F– Δ(argF‐lac)169 lon510 cpsB10::lac rpsL150	S Gottesman, NIH, USA
SG20781	F– Δ(argF‐lac)169 lon + cpsB10::lac rpsL150	S Gottesman, NIH, USA
MG1655	F– rph‐1	Laboratory collection
HR318	F– λ– rph‐1 btuB::Tn10 rpoB8	R. Harinarayanan, CDFD, India.
MGBT10	The same as MG1655, but has btuB::Tn10	This study, MG1655 X P1/(HR318)
MMRT6	The same as SG20780, but has btuB::Tn10 rpoB12	This study
MMRT23	The same as SG20780, but has btuB::Tn10 rpoB77	This study

Phage	Relevant genotype	Source/reference
P1	Vir	Laboratory collection, originally obtained from N Willets, UK

Name of the plasmid carrying hns variant alleles	Base change(s)/amino acid change present/functional defect(s) reported/reference	Source
pLGhns‐P116S	CCA to TCA Change of proline to serine at 116th amino acid position Shown to be defective in the recognition of curved DNA region, but retains nonspecific DNA binding [19, Ueguchi et al., 1996]	J Gowrishankar, CDFD, Hyderabad, India
pLGhns‐∆64	ATG to TGC (deletion of A results in a frameshift leading to formation of in‐frame Cys codon and a stop codon). Produces truncated H‐NS protein bearing only first 64 amino acids. Shown to be defective in DNA binding and higher‐order oligomerization [19, Ueguchi et al., 1996]	J Gowrishankar, CDFD, Hyderabad, India
pLGhns‐T55P	ACT to CCT Change of threonine to proline at 55th amino acid position Shown to be defective in higher‐order oligomerization [19, Ueguchi et al., 1996]	J Gowrishankar, CDFD, Hyderabad, India
pLGhns‐L26P	CTG to CCG Change of leucine to proline at 26th amino acid position Shown to be defective in higher‐order oligomerization [19, Ueguchi et al., 1996]	J Gowrishankar, CDFD, Hyderabad, India
pLGhns +	Wild‐type DNA‐binding and oligomerization functions are normal (reviewed by Refs 8, 13)	J Gowrishankar, CDFD, Hyderabad, India

All the above‐mentioned plasmids are derivatives of pLG339 (pSC101 replicon, Kan^R).