Polymorphism and selection of rpoS in pathogenic Escherichia coli

BMC Microbiology

Table 2 Polymorphic codons in rpoS among VTEC strains.

Codon	33	54	119	129	154	181	191	243	273	317
	Glu	Val	Leu	Arg	Ile	Thr	His	Glu	Val	Leu
Consensus	GAG	GTG	CTT	CGC	ATT	ACC	CAT	GAG	GTG	CTG
MG1655	C . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .
EDL933	. . .	. . .	. . .	. . T	. . .	. . A	. . .	. . .	. . A	. . .
CL106	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .
R82F2	. . .	. . A	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .
N00-4067	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . A
CL3	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .
N99-4390	. . .	. . .	. . G	. . .	. . C	. . .	. . C	T . .
N00-4859	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .
EC6-484	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . A
EC2-044	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .
EC3-377	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .	. . .

The rpoS gene in E. coli K-12 MG1655 strain was used as the reference for comparison. The G-C transition at codon 33 in MG1655 results in a conversion of glutamate to glutamine, while the G-T transversion in N99-4390 at codon 243 forms a stop codon resulting in a truncated RpoS protein. The other polymorphic sites are synonymous mutations.

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