title: Glutaminyl-tRNA synthetase: from genetics to molecular recognition.
abstract: Accurately aminoacylated tRNAs are an a priori requirement for translation of the genetic code. They are synthesized by the aminoacyl-tRNA synthetases which select both the correct amino acid and tRNA from a total of more than 400 possible combinations. Genetic, biochemical and structural studies have begun to reveal the mechanisms by which this specificity is achieved by Escherichia coli glutaminyl-tRNA synthetase (GlnRS). Sequence-specific interactions between GlnRS and tRNA(Gln) determine both the accuracy of tRNA selection and the efficiency of aminoacylation. Thus, amino acid recognition is tRNA-dependent. Consequently, while a noncognate tRNA may be recognized by GlnRS, the resulting tRNA-enzyme complex displays a considerably reduced affinity for glutamine compared to wild-type. This mechanism now provides a ready explanation as to why the majority of tRNA mischarging events, including those originally described over 25 years ago for GlnRS, impair cellular viability only to a limited degree.
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA.
authors.forename: M
authors.initials: M
authors.lastname: Ibba
authors.forename: K W
authors.initials: KW
authors.lastname: Hong
authors.forename: D
authors.initials: D
authors.lastname: Söll
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009154:Mutation; D009690:Nucleic Acid Conformation; D011487:Protein Conformation; D012351:RNA, Transfer, Gln / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012261:Ribonucleoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D012351:RNA, Transfer, Gln; D012261:Ribonucleoproteins; D000604:Amino Acyl-tRNA Synthetases