2.50
Hdl Handle:
http://hdl.handle.net/10033/15230
Title:
Crystal structure of a non-discriminating glutamyl-tRNA synthetase.
Authors:
Schulze, Jörg O; Masoumi, Ava; Nickel, Daniel; Jahn, Martina; Jahn, Dieter; Schubert, Wolf-Dieter; Heinz, Dirk W
Abstract:
Error-free protein biosynthesis is dependent on the reliable charging of each tRNA with its cognate amino acid. Many bacteria, however, lack a glutaminyl-tRNA synthetase. In these organisms, tRNA(Gln) is initially mischarged with glutamate by a non-discriminating glutamyl-tRNA synthetase (ND-GluRS). This enzyme thus charges both tRNA(Glu) and tRNA(Gln) with glutamate. Discriminating GluRS (D-GluRS), found in some bacteria and all eukaryotes, exclusively generates Glu-tRNA(Glu). Here we present the first crystal structure of a non-discriminating GluRS from Thermosynechococcus elongatus (ND-GluRS(Tel)) in complex with glutamate at a resolution of 2.45 A. Structurally, the enzyme shares the overall architecture of the discriminating GluRS from Thermus thermophilus (D-GluRS(Tth)). We confirm experimentally that GluRS(Tel) is non-discriminating and present kinetic parameters for synthesis of Glu-tRNA(Glu) and of Glu-tRNA(Gln). Anticodons of tRNA(Glu) (34C/UUC36) and tRNA(Gln) (34C/UUG36) differ only in base 36. The pyrimidine base of C36 is specifically recognized in D-GluRS(Tth) by the residue Arg358. In ND-GluRS(Tel) this arginine residue is replaced by glycine (Gly366) presumably allowing both cytosine and the bulkier purine base G36 of tRNA(Gln) to be tolerated. Most other ND-GluRS share this structural feature, leading to relaxed substrate specificity.
Affiliation:
Division of Structural Biology, German Research Centre for Biotechnology (GBF), Mascheroder Weg 1, D-38124 Braunschweig, Germany.
Citation:
Crystal structure of a non-discriminating glutamyl-tRNA synthetase. 2006, 361 (5):888-97 J. Mol. Biol.
Journal:
Journal of molecular biology
Issue Date:
1-Sep-2006
URI:
http://hdl.handle.net/10033/15230
DOI:
10.1016/j.jmb.2006.06.054
PubMed ID:
16876193
Type:
Article
Language:
en
ISSN:
0022-2836
Appears in Collections:
Publications from Division of Molekulare Struktur Biologie (MOSB)

Full metadata record

DC FieldValue Language
dc.contributor.authorSchulze, Jörg O-
dc.contributor.authorMasoumi, Ava-
dc.contributor.authorNickel, Daniel-
dc.contributor.authorJahn, Martina-
dc.contributor.authorJahn, Dieter-
dc.contributor.authorSchubert, Wolf-Dieter-
dc.contributor.authorHeinz, Dirk W-
dc.date.accessioned2007-12-14T15:02:09Z-
dc.date.available2007-12-14T15:02:09Z-
dc.date.issued2006-09-01-
dc.identifier.citationCrystal structure of a non-discriminating glutamyl-tRNA synthetase. 2006, 361 (5):888-97 J. Mol. Biol.en
dc.identifier.issn0022-2836-
dc.identifier.pmid16876193-
dc.identifier.doi10.1016/j.jmb.2006.06.054-
dc.identifier.urihttp://hdl.handle.net/10033/15230-
dc.description.abstractError-free protein biosynthesis is dependent on the reliable charging of each tRNA with its cognate amino acid. Many bacteria, however, lack a glutaminyl-tRNA synthetase. In these organisms, tRNA(Gln) is initially mischarged with glutamate by a non-discriminating glutamyl-tRNA synthetase (ND-GluRS). This enzyme thus charges both tRNA(Glu) and tRNA(Gln) with glutamate. Discriminating GluRS (D-GluRS), found in some bacteria and all eukaryotes, exclusively generates Glu-tRNA(Glu). Here we present the first crystal structure of a non-discriminating GluRS from Thermosynechococcus elongatus (ND-GluRS(Tel)) in complex with glutamate at a resolution of 2.45 A. Structurally, the enzyme shares the overall architecture of the discriminating GluRS from Thermus thermophilus (D-GluRS(Tth)). We confirm experimentally that GluRS(Tel) is non-discriminating and present kinetic parameters for synthesis of Glu-tRNA(Glu) and of Glu-tRNA(Gln). Anticodons of tRNA(Glu) (34C/UUC36) and tRNA(Gln) (34C/UUG36) differ only in base 36. The pyrimidine base of C36 is specifically recognized in D-GluRS(Tth) by the residue Arg358. In ND-GluRS(Tel) this arginine residue is replaced by glycine (Gly366) presumably allowing both cytosine and the bulkier purine base G36 of tRNA(Gln) to be tolerated. Most other ND-GluRS share this structural feature, leading to relaxed substrate specificity.en
dc.language.isoenen
dc.subject.meshAmino Acid Sequenceen
dc.subject.meshAnticodonen
dc.subject.meshBinding Sitesen
dc.subject.meshCatalysisen
dc.subject.meshCrystallography, X-Rayen
dc.subject.meshCyanobacteriaen
dc.subject.meshGlutamate-tRNA Ligaseen
dc.subject.meshGlutamic Aciden
dc.subject.meshModels, Molecularen
dc.subject.meshMolecular Sequence Dataen
dc.subject.meshProtein Bindingen
dc.subject.meshProtein Structure, Tertiaryen
dc.titleCrystal structure of a non-discriminating glutamyl-tRNA synthetase.en
dc.typeArticleen
dc.contributor.departmentDivision of Structural Biology, German Research Centre for Biotechnology (GBF), Mascheroder Weg 1, D-38124 Braunschweig, Germany.en
dc.identifier.journalJournal of molecular biologyen

Related articles on PubMed

All Items in HZI are protected by copyright, with all rights reserved, unless otherwise indicated.