Fig. 2

The information about genes, orthologous, regulatory activities, and promoters. a The distribution of orthologous gene number: The x-axis is the number interval of orthologous genes; the y-axis is the number of genes whose orthologous number is in the corresponding interval. The solid parts represent the genes having known regulatory activities. b The correlation between orthologous number and regulatory activities: The x-axis is the number interval of orthologous genes; the y-axis is the proportion of genes with known regulatory activities in corresponding gene groups. c The box-plot of orthologous number distribution for gene sets S1, S2 and S3. S1 represents the whole gene set of E. coli; S2 and S3 are the central metabolism genes and all pathway genes respectively. The genes in S2 and S3 have significantly more orthologous compared to S1 with Wilcox p-values both as 2.2e-16, and the genes in S2 have little more orthologous than S3 with Wilcox p-value as 0.17. d The distribution of orthologous operon number: The x-axis is number interval of orthologous operons; and the y-axis is the number of operons whose orthologous number within corresponding intervals. The solid parts represent the operons having known TFBSs in regulatory regions