Protein maximum likelihood trees of the long version of glucosamine-6-phosphate isomerase ( nagB gene). Phylogenetic tree based on 560 unambiguously aligned aa positions from the glucosamine-6-phosphate isomerase sequences that have the long C-terminal extension (box B in Figure 4). In a separate analysis the partial Mastigamoeba balamuthi sequence was included and its position is indicated with an arrow with the bootstrap support value in parenthesis. The tree is arbitrarily rooted. Details about the phylogenetic analyses are found in the Methods section and Additional File 2. Labelling as in Figure 2.