Figure 3.

Neighbor-joining analysis of type IV secretion system gene sequences. (A) Phylogenetic tree calculated with MLST sequences for fully sequenced strains only, with phylogeography assignments based on the Neighbor-joining tree shown in Figure  2. Note that unequivocal classification of strains PeCan4 and PeCan18 was not possible. (B) Phylogenetic tree calculated from concatenated virB9, virB11 and virD4 ortholog sequences of all ICEHptfs3 and ICEHptfs4 islands. (C) Neighbor-joining tree calculated from DNA sequences of methylase/helicase (hpp12_447/pz21) orthologs. Orthologs associated with ICEHptfs3 elements are marked by blue branch lines, and orthologs associated with ICEHptfs4 elements by red branch lines. Black lines indicate hybrid elements or the presence of two different elements in the same strain. Colouring of individual strains by phylogeographic origin is shown according to the tree in Figure  2.