title: The NMR structure of Escherichia coli ribosomal protein L25 shows homology to general stress proteins and glutaminyl-tRNA synthetases.
abstract: The structure of the Escherichia coli ribosomal protein L25 has been determined to an r.m.s. displacement of backbone heavy atoms of 0.62 +/- 0.14 A by multi-dimensional heteronuclear NMR spectroscopy on protein samples uniformly labeled with 15N or 15N/13C. L25 shows a new topology for RNA-binding proteins consisting of a six-stranded beta-barrel and two alpha-helices. A putative RNA-binding surface for L25 has been obtained by comparison of backbone 15N chemical shifts for L25 with and without a bound cognate RNA containing the eubacterial E-loop that is the site for binding of L25 to 5S ribosomal RNA. Sequence comparisons with related proteins, including the general stress protein, CTC, show that the residues involved in RNA binding are highly conserved, thereby providing further confirmation of the binding surface. Tertiary structure comparisons indicate that the six-stranded beta-barrels of L25 and of the tRNA anticodon-binding domain of glutaminyl-tRNA synthetase are similar.
authors.affiliation: Abteilung Molekulare Biophysik/NMR Spektroskopie, Institut für Molekulare Biotechnologie e. V., Postfach 100813, 07708 Jena, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Stoldt
authors.forename: J
authors.initials: J
authors.lastname: Wöhnert
authors.forename: M
authors.initials: M
authors.lastname: Görlach
authors.forename: L R
authors.initials: LR
authors.lastname: Brown
mesh_terms: D000595:Amino Acid Sequence; D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry; D001665:Binding Sites / Q000235:genetics; D004926:Escherichia coli / Q000737:chemistry*; D006360:Heat-Shock Proteins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012341:RNA, Ribosomal, 5S / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry; D012269:Ribosomal Proteins / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; D012341:RNA, Ribosomal, 5S; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins; C031127:ribosomal protein L25; D000604:Amino Acyl-tRNA Synthetases; C020659:glutaminyl-tRNA synthetase