title: Structural basis of anticodon loop recognition by glutaminyl-tRNA synthetase.
abstract: The refined crystal structure of Escherichia coli glutaminyl transfer RNA synthetase complexed with transfer RNA(Gln) and ATP reveals that the structure of the anticodon loop of the enzyme-bound tRNA(Gln) differs extensively from that of the known crystal structures of uncomplexed tRNA molecules. The anticodon stem is extended by two non-Watson-Crick base pairs, leaving the three anti-codon bases unpaired and splayed out to bind snugly into three separate complementary pockets in the protein. These interactions suggest that the entire anticodon loop provides essential sites for glutaminyl tRNA synthetase discrimination among tRNA molecules.
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511.
authors.forename: M A
authors.initials: MA
authors.lastname: Rould
authors.forename: J J
authors.initials: JJ
authors.lastname: Perona
authors.forename: T A
authors.initials: TA
authors.lastname: Steitz
mesh_terms: D000494:Allosteric Regulation; D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry / Q000378:metabolism*; D000926:Anticodon / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D003196:Computer Graphics; D004926:Escherichia coli / Q000201:enzymology; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011487:Protein Conformation; D012351:RNA, Transfer, Gln / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000926:Anticodon; D012351:RNA, Transfer, Gln; D000604:Amino Acyl-tRNA Synthetases; C020659:glutaminyl-tRNA synthetase