Skip to main content
Figure 8 | BMC Evolutionary Biology

Figure 8

From: Evolutionary constraints permeate large metabolic networks

Figure 8

Two NAD+ synthase genes that "avoid" each other. KEGG orthologs K01916 and K01950 are thought to encode NAD+ synthases that use ammonium (blue reaction) and glutamate (green reaction) as amide donors, respectively. The tree shown is a 16S rDNA-based maximum-likelihood phylogenetic tree of the bacterial species analyzed here. Bars along the circumference of the tree indicate whether a specific reaction (as indicated by the bar's color) occurs in a genome or not. Bars containing two colors indicate that both orthologs occur in a given species. These orthologs are highly negatively associated, as illustrated by their almost exclusively complementary distribution in the analyzed genomes.

Back to article page