title: Structural bases of transfer RNA-dependent amino acid recognition and activation by glutamyl-tRNA synthetase.
abstract: Glutamyl-tRNA synthetase (GluRS) is one of the aminoacyl-tRNA synthetases that require the cognate tRNA for specific amino acid recognition and activation. We analyzed the role of tRNA in amino acid recognition by crystallography. In the GluRS*tRNA(Glu)*Glu structure, GluRS and tRNA(Glu) collaborate to form a highly complementary L-glutamate-binding site. This collaborative site is functional, as it is formed in the same manner in pretransition-state mimic, GluRS*tRNA(Glu)*ATP*Eol (a glutamate analog), and posttransition-state mimic, GluRS*tRNA(Glu)*ESA (a glutamyl-adenylate analog) structures. In contrast, in the GluRS*Glu structure, only GluRS forms the amino acid-binding site, which is defective and accounts for the binding of incorrect amino acids, such as D-glutamate and L-glutamine. Therefore, tRNA(Glu) is essential for formation of the completely functional binding site for L-glutamate. These structures, together with our previously described structures, reveal that tRNA plays a crucial role in accurate positioning of both L-glutamate and ATP, thus driving the amino acid activation.
authors.affiliation: Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Sekine
authors.forename: Mika
authors.initials: M
authors.lastname: Shichiri
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bernier
authors.forename: Robert
authors.initials: R
authors.lastname: Chênevert
authors.forename: Jacques
authors.initials: J
authors.lastname: Lapointe
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Yokoyama
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry; D001665:Binding Sites; D018360:Crystallography, X-Ray; D005975:Glutamate-tRNA Ligase / Q000737:chemistry* / Q000378:metabolism; D018698:Glutamic Acid / Q000737:chemistry; D008954:Models, Biological; D008958:Models, Molecular; D008968:Molecular Conformation; D011485:Protein Binding; D011487:Protein Conformation; D012343:RNA, Transfer / Q000737:chemistry*; D016963:Thermus thermophilus / Q000201:enzymology
chemical_list: D000596:Amino Acids; D018698:Glutamic Acid; D012343:RNA, Transfer; D000604:Amino Acyl-tRNA Synthetases; D005975:Glutamate-tRNA Ligase