title: Crystal structure of asparagine synthetase reveals a close evolutionary relationship to class II aminoacyl-tRNA synthetase.
abstract: The crystal structure of E. coli asparagine synthetase has been determined by X-ray diffraction analysis at 2.5 A resolution. The overall structure of the enzyme is remarkably similar to that of the catalytic domain of yeast aspartyl-tRNA synthetase despite low sequence similarity. These enzymes have a common reaction mechanism that implies the formation of an aminoacyl-adenylate intermediate. The active site architecture and most of the catalytic residues are also conserved in both enzymes. These proteins have probably evolved from a common ancestor even though their sequence similarities are small. The functional and structural similarities of both enzymes suggest that new enzymatic activities would generally follow the recruitment of a protein catalyzing a similar chemical reaction.
authors.affiliation: Institute for Chemical Research, Kyoto University, Japan. oda@pclsp2.kuicr.kyoto-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Nakatsu
authors.forename: H
authors.initials: H
authors.lastname: Kato
authors.forename: J
authors.initials: J
authors.lastname: Oda
mesh_terms: D000595:Amino Acid Sequence; D000604:Amino Acyl-tRNA Synthetases / Q000648:ultrastructure*; D001217:Aspartate-Ammonia Ligase / Q000648:ultrastructure*; D001224:Aspartic Acid / Q000737:chemistry; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D001224:Aspartic Acid; D000604:Amino Acyl-tRNA Synthetases; D001217:Aspartate-Ammonia Ligase