Two conformations of a crystalline human tRNA synthetase–tRNA complex: implications for protein synthesis
| Autor: | Manal A. Swairjo, Xiang-Lei Yang, Caroline Köhrer, Karla L. Ewalt, Paul Schimmel, Jianming Liu, Uttam L. RajBhandary, Duncan E. McRee, Francella J. Otero, Robert J. Skene |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Models
Molecular Protein Conformation Stereochemistry Molecular Sequence Data Tryptophan-tRNA Ligase Aminoacylation Tryptophan—tRNA ligase Biology Crystallography X-Ray Article General Biochemistry Genetics and Molecular Biology chemistry.chemical_compound Peptide Elongation Factor 1 Protein structure Anticodon Humans Amino Acid Sequence Molecular Biology General Immunology and Microbiology Aminoacyl tRNA synthetase General Neuroscience Tryptophan RNA Transfer Trp TRNA binding Elongation factor chemistry Biochemistry Protein Biosynthesis Transfer RNA Nucleic Acid Conformation T arm Crystallization Sequence Alignment Protein Binding |
| Zdroj: | The EMBO Journal. 25:2919-2929 |
| ISSN: | 1460-2075 0261-4189 |
| Popis: | Aminoacylation of tRNA is the first step of protein synthesis. Here, we report the co-crystal structure of human tryptophanyl-tRNA synthetase and tRNATrp. This enzyme is reported to interact directly with elongation factor 1alpha, which carries charged tRNA to the ribosome. Crystals were generated from a 50/50% mixture of charged and uncharged tRNATrp. These crystals captured two conformations of the complex, which are nearly identical with respect to the protein and a bound tryptophan. They are distinguished by the way tRNA is bound. In one, uncharged tRNA is bound across the dimer, with anticodon and acceptor stem interacting with separate subunits. In this cross-dimer tRNA complex, the class I enzyme has a class II-like tRNA binding mode. This structure accounts for biochemical investigations of human TrpRS, including species-specific charging. In the other conformation, presumptive aminoacylated tRNA is bound only by the anticodon, the acceptor stem being free and having space to interact precisely with EF-1alpha, suggesting that the product of aminoacylation can be directly handed off to EF-1alpha for the next step of protein synthesis. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text