Figure 4

Lysine and arginine use in archaeal proteomes, relative to genome G+C content. The dotted lines represent the linear fit to the hyperthermophile data and the goodness of fit values. The archaeal classification as hyperthermophiles, thermophiles and mesophiles follows that of the NCBI Genome Project database [100]. The proposed pathways for the biosynthesis of the two amino acids, the genes predicted to be involved and the metabolic costs of the two reactions are shown below the graphs.