Unrooted phylogenetic tree (radial view) of the TrpEa protein family. Organismal acronyms are defined in Table 1. Phylogenetic reconstruction of the inferred amino-acid sequence was accomplished by the neighbor-joining method using the PHYLIP program. The detailed order of branching for cyanobacterial and higher-plant sequences is shown in Figure 3. Archaeal proteins are visualized in magenta, and the yellow line indicates the TrpEa protein from C. trachomatis, which is probably encoded by a pseudogene.