title: Relationship of two human tRNA synthetases used in cell signaling.
abstract: Human tyrosyl-tRNA synthetase (TyrRS) and tryptophanyl-tRNA synthetase (TrpRS) are closely related, dual function enzymes that act in protein biosynthesis and angiogenesis. The recent crystallographic structures of these two enzymes show that they adopt remarkably similar three-dimensional (3D) architectures, being more like each other than like their respective prokaryotic orthologs. In particular, adaptations to the anticodon recognition domain of TyrRS cause distinct appended domains in TyrRS and TrpRS to occupy the same 3D space and thus to mask a common surface on each synthetase. Thought to be important for cell-signaling activity, this surface is made accessible by proteolytic cleavage, thereby activating the cell-signaling function of these enzymes.
authors.affiliation: The Skaggs Institute for Chemical Biology, The Scripps Research Institute, BCC379, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Xiang-Lei
authors.initials: XL
authors.lastname: Yang
authors.forename: Paul
authors.initials: P
authors.lastname: Schimmel
authors.forename: Karla L
authors.initials: KL
authors.lastname: Ewalt
mesh_terms: D042501:Angiogenic Proteins / Q000737:chemistry / Q000502:physiology; D000926:Anticodon / Q000378:metabolism; D001665:Binding Sites; D002465:Cell Movement / Q000502:physiology; D016207:Cytokines / Q000737:chemistry / Q000502:physiology; D006801:Humans; D008958:Models, Molecular; D009363:Neoplasm Proteins / Q000737:chemistry / Q000502:physiology; D011487:Protein Conformation; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D040681:Structural Homology, Protein; D014369:Tryptophan-tRNA Ligase / Q000737:chemistry / Q000378:metabolism*; D014448:Tyrosine-tRNA Ligase / Q000737:chemistry / Q000378:metabolism*
chemical_list: D042501:Angiogenic Proteins; D000926:Anticodon; D016207:Cytokines; D009363:Neoplasm Proteins; D016601:RNA-Binding Proteins; C077219:small inducible cytokine subfamily E, member 1; D014448:Tyrosine-tRNA Ligase; D014369:Tryptophan-tRNA Ligase