Figure 2

Phylogenetic analyses of Threonyl-tRNA synthetases (ThrRS). (A) Maximum likelihood phylogenetic tree showing the distribution of the two forms of ThrRS across the three domains of life. Branches are color-coded based on the domain. (B) Maximum likelihood phylogenetic tree showing the distribution of the two forms of ThrRS in Archaea, labeled ThrRS-R and ThrRS-C. Taxa names in blue are from the phylum Euryarchaeota and in red are Crenarchaeota. Members of other archaeal phyla are represented in black text. Orders common to both clades are shown in colored boxes. (C) Maximum likelihood phylogenetic tree of Archaea based on concatenated 16S and 23S rRNA sequences. The tree was rooted using bacterial homologs from Thermotoga maritima and Aquifex aeolicae.