Fig. 5: Distribution and evolution of peptidoglycan biosynthesis within the class.

a Cladogram inferred from the Dehalococcoidia phylogenomic tree serving as evolutionary hypothesis for ancestral character state reconstruction. Orders from diverse environments are shaded in gray, while the Tepidiformales are shaded in red and indicated with red branches, and the Marine Radiation is shaded in blue, with SAR202 lineages indicated with blue branches and asterisks and blue text in the key. The presence of three sets of conserved genes is indicated on the cladogram. Group 1 genes encode proteins for the central DAP-type peptidoglycan biosynthetic pathway (purple), Group 2 (pink), and Group 3 (gray) genes encode proteins involved in peptidoglycan synthesis and other metabolic pathways for amino acids and secondary metabolites. The full Group 1 gene set is predicted as present in the ancestor to the class (purple dot with green outline), with a full loss of Group 1 genes predicted at the node reflecting an ancestor to orders 10–25. b Diagram of the DAP-type peptidoglycan biosynthetic pathway, and the relative position of enzymes encoded by the different gene sets within the pathway.