Figure 4

Relationship between phylogeny and T6SS gene content. Rows represent T6SS loci and columns represent protein functional classes (based on COG assignment). The tree on the left is the consensus phylogenetic tree (super-tree, see Materials and methods §5, manually rooted) whereas the upper dendrogram represents a hierarchical clustering of the phylogenetic profiles. Core T6SS conserved proteins are depicted on the right columns with the same color code as in Figures 1 and 3. Presence and absence of conserved accessory proteins (grey and light green) highlights the presence of sub-groups numbered from I to V. Letters in front of bacteria names correspond to the four groups proposed by Bingle and co-workers [14], '#' marks functional T6SS loci depicted in Table 1 and included in this figure. The two major sub-trees have been split and displayed separately for clarity. Light blue and light green highlighted groups are examples of close T6SS loci associated to bacteria with similar ecological niche. These two groups are associated to marine bacteria (sub-group V, blue) and plant associated bacteria (sub-group IV, green).