Table 2. Conservation of the repeated regions of the 10 (+ mutS) most biased genes of E.coli K12 comparing with other proteobacteria.

	No. of orthologues	Biased genes	DNA		Protein
			–	+	–	+
aceF	8	8	5	0	0	1
betB	10	2	0	0	0	0
csgA	2	2	0	0	0	0
cyoC	8	6	0	0	0	0
cyoE	11	4	0	1	0	0
dnaA	12	4	0	1	0	0
lamB	4	1	0	0	1	0
mutL	12	4	0	2	0	7
mutS	12	3	4	2	2	0
sbcC	5	5	1	0	0	1
sodB	12	2	0	0	0	0

The table displays the number of orthologues among these genomes, the number of such orthologues over-representing close direct repeats, and the relative conservation of the regions bearing repeats in the E.coli K12 gene. For the latter, we aligned the protein orthologues and analysed if the regions including repeats in E.coli K12 presented a higher number of mismatches in the alignment (χ² test, P < 0.05). For the analyses at the DNA level, the protein alignments were back translated to DNA and the same procedure was applied. Columns under ‘–’ indicate the number of orthologues with significantly smaller conservation at the location of repeats in E.coli K12, ‘+’ indicates significantly higher conservation.