Fig 1.

Illustration of organization of domains of human, yeast, and bacterial TyrRS. All TyrRSs have a catalytic Rossmann fold domain (yellow) and an anticodon-recognition domain (green). In addition, human TyrRS has an EMAP II-like C-terminal domain (blue). In contrast, bacterial TyrRS has a smaller C-terminal extension (purple), which is distinct from the human TyrRS C domain. The critical ELR tripeptide for cytokine activity is highlighted in orange on human TyrRS. The corresponding tripeptides also are highlighted on yeast and bacterial TyrRSs. These tripeptides are not conserved among yeast and bacterial TyrRSs.