title: Architectures of class-defining and specific domains of glutamyl-tRNA synthetase.
abstract: The crystal structure of a class I aminoacyl-transfer RNA synthetase, glutamyl-tRNA synthetase (GluRS) from Thermus thermophilus, was solved and refined at 2.5 A resolution. The amino-terminal half of GluRS shows a geometrical similarity with that of Escherichia coli glutaminyl-tRNA synthetase (GlnRS) of the same subclass in class I, comprising the class I-specific Rossmann fold domain and the intervening subclass-specific alpha/beta domain. These domains were found to have two GluRS-specific, secondary-structure insertions, which then participated in the specific recognition of the D and acceptor stems of tRNA(Glu) as indicated by mutagenesis analyses based on the docking properties of GluRS and tRNA. In striking contrast to the beta-barrel structure of the GlnRS carboxyl-terminal half, the GluRS carboxyl-terminal half displayed an all-alpha-helix architecture, an alpha-helix cage, and mutagenesis analyses indicated that it had a role in the anticodon recognition.
authors.affiliation: Department of Biophysics and Biochemistry, School of Science, University of Tokyo, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Nureki
authors.forename: D G
authors.initials: DG
authors.lastname: Vassylyev
authors.forename: K
authors.initials: K
authors.lastname: Katayanagi
authors.forename: T
authors.initials: T
authors.lastname: Shimizu
authors.forename: S
authors.initials: S
authors.lastname: Sekine
authors.forename: T
authors.initials: T
authors.lastname: Kigawa
authors.forename: T
authors.initials: T
authors.lastname: Miyazawa
authors.forename: S
authors.initials: S
authors.lastname: Yokoyama
authors.forename: K
authors.initials: K
authors.lastname: Morikawa
mesh_terms: D000595:Amino Acid Sequence; D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry; D000926:Anticodon; D005075:Biological Evolution; D003196:Computer Graphics; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology; D005975:Glutamate-tRNA Ligase / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012352:RNA, Transfer, Glu / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D016963:Thermus thermophilus / Q000201:enzymology*
chemical_list: D000926:Anticodon; D012352:RNA, Transfer, Glu; D000604:Amino Acyl-tRNA Synthetases; D005975:Glutamate-tRNA Ligase; C020659:glutaminyl-tRNA synthetase