Figure 1From: The primordial metabolism: an ancestral interconnection between leucine, arginine, and lysine biosynthesisThe extant lysine, leucine, and arginine biosynthetic routes. Evolutionary relationship between lysine, leucine, and arginine biosynthetic genes. Genes sharing the same colour and the same level are homologs. Genes coloured in white have no homolog in the metabolic routes taken into account in this work (modified from Velasco et al 2002 [19]).Back to article page