Figure 6

Evolutionary relationships of the different type VI secretion systems of Pantoea ananatis using concatenated TssB and TssC amino acid sequences. Phylogenetic analysis were conducted in MEGA6 [90]. The amino acid substitution model was determined by ProtTest [91]. The evolutionary history was inferred using the Maximum Likelihood method based on the Le and Gascuel (LG) + G + F model [92]. The percentage of replicate trees in which the associated taxa clustered together in the bootstrap test (1000 replicates) is shown next to the branches. The tree is drawn to scale, with branch lengths measured in the number of substitutions per site. The TssB/C homologs used in this study are indicated next to the name of the bacteria. Blue octagons represent T6SS phylogenetic Groups A-D proposed by Bingle et al. [23]. Representative position of PA T6SS-1 and PA T6SS-2 are shown in blue and green rectangles, respectively. Details of all bacteria used in are given in (Additional file 10: Table S16).