Figure 5

The phylogenetic distribution and connectivity of enzymes in different functional classes. a) Function and phylogenetic distribution. The E. coli enzymes were classified into 7 functional classes (amino acid metabolism, energy metabolism, lipid metabolism, nucleotide metabolism, sugar metabolism, other biosynthesis and other degradation) and divided into enzymes which are represented in 1, 2 or 3 domains of life. 100 000 randomized networks were generated for comparison and Z-score calculation. b) Connectivity and function. The enzymes were divided into functional classes and the Z-scores for the connectivities of each functional class were calculated for the network where the 15 most promiscuous compounds have been removed.