Biomaterial Database

Structural and mutational studies of the recognition of the arginine tRNA-specific major identity element, A20, by arginyl-tRNA synthetase. 2001

A Shimada, and O Nureki, and M Goto, and S Takahashi, and S Yokoyama

Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.

Arginyl-tRNA synthetase (ArgRS) recognizes two major identity elements of tRNA(Arg): A20, located at the outside corner of the L-shaped tRNA, and C35, the second letter of the anticodon. Only a few exceptional organisms, such as the yeast Saccharomyces cerevisiae, lack A20 in tRNA(Arg). In the present study, we solved the crystal structure of a typical A20-recognizing ArgRS from Thermus thermophilus at 2.3 A resolution. The structure of the T. thermophilus ArgRS was found to be similar to that of the previously reported S. cerevisiae ArgRS, except for short insertions and a concomitant conformational change in the N-terminal domain. The structure of the yeast ArgRS.tRNA(Arg) complex suggested that two residues in the unique N-terminal domain, Tyr(77) and Asn(79), which are phylogenetically invariant in the ArgRSs from all organisms with A20 in tRNA(Arg)s, are involved in A20 recognition. However, in a docking model constructed based on the yeast ArgRS.tRNA(Arg) and T. thermophilus ArgRS structures, Tyr(77) and Asn(79) are not close enough to make direct contact with A20, because of the conformational change in the N-terminal domain. Nevertheless, the replacement of Tyr(77) or Asn(79) by Ala severely reduced the arginylation efficiency. Therefore, some conformational change around A20 is necessary for the recognition. Surprisingly, the N79D mutant equally recognized A20 and G20, with only a slight reduction in the arginylation efficiency as compared with the wild-type enzyme. Other mutants of Asn(79) also exhibited broader specificity for the nucleotide at position 20 of tRNA(Arg). We propose a model of A20 recognition by the ArgRS that is consistent with the present results of the mutational analyses.

UI	MeSH Term	Description	Entries
D008958	Models, Molecular	Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.	Molecular Models,Model, Molecular,Molecular Model
D009690	Nucleic Acid Conformation	The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.	DNA Conformation,RNA Conformation,Conformation, DNA,Conformation, Nucleic Acid,Conformation, RNA,Conformations, DNA,Conformations, Nucleic Acid,Conformations, RNA,DNA Conformations,Nucleic Acid Conformations,RNA Conformations
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino
D001126	Arginine-tRNA Ligase	An enzyme that activates arginine with its specific transfer RNA. EC 6.1.1.19.	Arginyl T RNA Synthetase,Arg-tRNA Ligase,Arginyl-tRNA Synthetase,Arg tRNA Ligase,Arginine tRNA Ligase,Arginyl tRNA Synthetase,Ligase, Arg-tRNA,Ligase, Arginine-tRNA,Synthetase, Arginyl-tRNA
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D012347	RNA, Transfer, Arg	A transfer RNA which is specific for carrying arginine to sites on the ribosomes in preparation for protein synthesis.	Arginine-Specific tRNA,Transfer RNA, Arg,tRNAArg,tRNA(Arg),Arg Transfer RNA,Arginine Specific tRNA,RNA, Arg Transfer,tRNA, Arginine-Specific
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker
D016296	Mutagenesis	Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.	Mutageneses
D016963	Thermus thermophilus	A species of gram-negative, aerobic, rod-shaped bacteria found in hot springs of neutral to alkaline pH, as well as in hot-water heaters.