The evolutionary conservation of promoters is limited to Gammaproteobacteria and to sigma70 promoters. In general an promoter is conserved if, i) the position of the promoter from the gene start is conserved, or ii) the promoter sequence recognized by the sigma70 factor is conserved (p < 0.0001). To avoid redundancy, the orthologous regions were purged using the program Purge-Sequence from RSAtools. Orthologs consisted of BLAST reciprocal best hits using soft masking and Smith-Waterman alignments.

First gene	Promoter name	Evolutionary conservation ratio (nd)	Footprint conservation
adiC	adiCp7	(nd)
amn	amnp1	(nd)
argP	argPp	(nd)
asr	asrp	(nd)
	asrp2	(nd)
asr	asrp	(nd)
	asrp2	(nd)
cra	fruRp8	(nd)
cusC	cusCp	0.01
cusR	cusRp	0.12
eda	edap1	(nd)
	edap2	(nd)
	edap3	(nd)
	eddp	0.02
feaR	feaRp	(nd)
	feaRp1	(nd)
	feaRp2	(nd)
	feaRp3	(nd)
gadX	gadAp	(nd)
	gadAp2	(nd)
	gadXp	(nd)
	gadXp	(nd)
gadX	gadAp	(nd)
	gadAp2	(nd)
	gadXp	(nd)
	gadXp	(nd)
hiuH	hiuHp	(nd)
mipA	mipAp	(nd)
ompF	ompFp	(nd)
	ompFp2	(nd)
ompF	ompFp	(nd)
	ompFp2	(nd)
phnC	phnCp	(nd)
phoA	phoAp	(nd)
phoB	phoBp	0.10
phoE	phoEp	(nd)
phoH	phoHp1	(nd)
	phoHp2	(nd)
phoQ	phoPp1	(nd)
	phoPp2	(nd)
	phoPp3	(nd)
	phoQp5	(nd)
phoU	phoUp	0.01
	pstBp1	0.01
	pstBp2	(nd)
	pstBp3	0.01
	pstCp	0.01
	pstCp2	(nd)
	pstSp	0.02
	pstSp2	(nd)
pitB	pitBp	0.06
prpR	prpRp	(nd)
psiE	psiEp	0.05
pstS	pstSp	0.02
	pstSp	0.02
	pstSp	0.02
	pstSp2	(nd)
	pstSp2	(nd)
	pstSp2	(nd)
pstS	pstSp	0.02
	pstSp	0.02
	pstSp	0.02
	pstSp2	(nd)
	pstSp2	(nd)
	pstSp2	(nd)
pstS	pstSp	0.02
	pstSp	0.02
	pstSp	0.02
	pstSp2	(nd)
	pstSp2	(nd)
	pstSp2	(nd)
pstS	pstSp	0.02
	pstSp	0.02
	pstSp	0.02
	pstSp2	(nd)
	pstSp2	(nd)
	pstSp2	(nd)
pstS	pstSp	0.02
	pstSp	0.02
	pstSp	0.02
	pstSp2	(nd)
	pstSp2	(nd)
	pstSp2	(nd)
pstS	pstSp	0.02
	pstSp	0.02
	pstSp	0.02
	pstSp2	(nd)
	pstSp2	(nd)
	pstSp2	(nd)
sbcD	sbcDp	0.06
tktB	talAp1	(nd)
	talAp2	(nd)
	tktBp	(nd)
ugpB	ugpBp1	0.34
	ugpBp2	0.03
ugpB	ugpBp1	0.34
	ugpBp2	0.03
rspR	ydfHp	(nd)
yegH	yegHp	(nd)
rcdB	yhjCp	(nd)
waaH	yibDp1	0.17
ytfK	ytfKp1	(nd)
	ytfKp2	(nd)