Figure 5.

Phylogenetic tree of metazoan Clade 1 and Clade 2 pantothenate kinase protein sequences. Branches with bootstrap values greater than 70% have a black circular node. (a) Clade 1 metazoan PANK tree. Sequences terminating with red circular nodes encode for a Clade 1 bifunctional PANK/phosphatase, and the two sequences ending with blue circular nodes encode for Clade 1 monofunctional PANK. PANK sequences harboring substitutions to the key catalytic residues are highlighted by the yellow boxes. Choanoflagellida and Filasterea are single cell eukaryotes that are the closest living relatives to metazoans (blue boxes). (b) Monofunctional metazoan Clade 2 PANK subtree. Organisms belonging to the Gnathostomata lineage encode for 2–3 Clade 2 PANK genes with a recent common ancestor, suggesting a duplication of the Clade 2 PANK gene in the common ancestor of Gnathostomata.