Table 2.

List of additional genes under positive selection across the six Escherichia coli genomes using the M1a-M2a test

Gene	P -value a	KO b	COG	Pathway	Enrichment c	Function
alaS	0.000	K01872	J	ko00970	0.3094	Alanyl-tRNA synthetase
cobU	0.046	K02231	H	ko00860	0.6536	Bifunctional cobinamide kinase and cobinamide phosphate guanylyltransferase
dacC	0.024	K07258	M	ko00550	0.6806	D-alanyl-D-alanine carboxypeptidase
eutA	0.000	K04019	E	ko00564	0.6025	Reactivating factor for ethanolamine ammonia lyase
fliC	0.000	K02406	N	ko02020	0.1939	Flagellar filament structural protein
hchA	0.000	K05523	R	-	-	Hsp31 molecular chaperone
nfsA	0.000	K07734	K	-	-	Nitroreductase A
pgl	0.000	K07404	G	ko00030	0.3210	6-phosphogluconolactonase
yadB	0.000	K01894	J	-	-	Glutamyl-Q tRNA synthetase
yebN	0.000	-	S	-	-	Conserved inner membrane protein
yddV	0.000	K13069	T	-	-	Predicted diguanylate cyclase
yfdF	0.041	-	-	-	-	Hypothetical protein
ygfI	0.013	-	K	-	-	Putative DNA-binding transcriptional regulator
ygeR	0.000	K12943	M	-	-	Lipoprotein

^a The P-value shown is the smallest one among different fragments if there is a strong signal of recombination.

^b “-” indicates that no functional term was assigned.

^c The “enrichment” represents P-value of hypergeometric distribution for each KEGG pathway.