Parallel Evolution and Horizontal Gene Transfer of the pst Operon in Firmicutes from Oligotrophic Environments

Figure 2

Maximum likelihood phylogenetic reconstruction of the concatenated PstC, PstA, and PstB (PstBB) protein sequences encoded by the pst operon. Branch colors indicate the two divergent clades: subtilis-like and cereus-like. Tag colors indicate the type of habitat where each species is found. Bootstrap values above 70% are indicated with an asterisk. The phylogeny of the individual proteins has a very similar topology (data not shown).