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

Figure 1

Gene architecture of the pst operon in different groups of bacteria. A: Bacillus cereus group, marine Bacillus and Clostridium; B: Listeria and Streptococcus; C: Bacillus subtilis group, Bacillus marisflavi, and Bacillus sp. CH108; D: Brevibacillus, Oceanobacillus, Desulfitobacterium, Acaryochloris; E: Synechococcus, Geobacillus kaustophilus, Sebaldella termitidis, B. cereus group. In C–E, the regulatory gene phoU is found elsewhere in the genome, not as part of the operon or entirely missing.