Figure 2
From: Evolutionary distinctiveness of fatty acid and polyketide synthesis in eukaryotes
Comparative evolution of fatty acid and polyketide synthase. (a) Concatenated phylogeny, inferred from protein sequences of five enzymes (3-ketoacyl ACP synthase III; S-malonyltransacylase; 3-hydroxyacyl-ACP dehydratase; enoyl-ACP reductase; trans3-ketoacyl ACP reductase, 1431 characters) involved in type II fatty acid synthesis (inferred using RAxML, GAMMA model of rate heterogeneity, 1000 bootstraps). Solid circles indicate bootstrap values above ⩾90. (b) For comparison, a dated molecular clock phylogeny of the eukaryotic tree of life, showing absolute time scale (million years) (from Parfrey et al., 2011). These phylogenetic analyses show that evolution of fatty acid synthase genes broadly follow the evolution pattern of the organism. (c) Phylogenetic analysis of 25 type II 3-ketoacyl ACP synthase II and 67 type I ketosynthase domains from prokaryotic and eukaryotic polyketide synthases and fatty acid synthases, showing the position of each major group, inferred in RAxML using GAMMA model of rate heterogeneity and 1000 bootstraps. Solid circles indicate bootstrap values above ⩾90. Owing to relaxed selection pressure, polyketide synthase genes were retained/lost by protists based on the functionality their polyketide product provided the organism.
