Alanyl-tRNA synthetase crystal structure and design for acceptor-stem recognition
| Autor: | Martha A. Lovato, Manal A. Swairjo, Robert J. Skene, Francella J. Otero, Lluís Ribas de Pouplana, Xiang-Lei Yang, Paul Schimmel, Duncan E. McRee |
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| Rok vydání: | 2003 |
| Předmět: |
Models
Molecular Base pair Stereochemistry Amino Acid Motifs Aminoacylation Crystallography X-Ray Protein Structure Secondary Substrate Specificity Protein structure Bacterial Proteins Escherichia coli Amino Acid Sequence Cloning Molecular Molecular Biology Base Pairing chemistry.chemical_classification Aquifex aeolicus DNA ligase Binding Sites biology Sequence Homology Amino Acid Alanine-tRNA Ligase Cell Biology Genetic code biology.organism_classification Amino acid Protein Structure Tertiary Kinetics RNA Bacterial chemistry Biochemistry Transfer RNA Hydrophobic and Hydrophilic Interactions |
| Zdroj: | Molecular cell. 13(6) |
| ISSN: | 1097-2765 |
| Popis: | Early work on aminoacylation of alanine-specific tRNA (tRNA(Ala)) by alanyl-tRNA synthetase (AlaRS) gave rise to the concept of an early "second genetic code" imbedded in the acceptor stems of tRNAs. A single conserved and position-specific G:U base pair in the tRNA acceptor stem is the key identity determinant. Further understanding has been limited due to lack of a crystal structure of the enzyme. We determined a 2.14 A crystal structure of the 453 amino acid catalytic fragment of Aquifex aeolicus AlaRS. It contains the catalytic domain characteristic of class II synthetases, a helical domain with a hairpin motif critical for acceptor-stem recognition, and a C-terminal domain of a mixed alpha/beta fold. Docking of tRNA(Ala) on AlaRS shows critical contacts with the three domains, consistent with previous mutagenesis and functional data. It also suggests conformational flexibility within the C domain, which might allow for the positional variation of the key G:U base pair seen in some tRNA(Ala)s. |
| Databáze: | OpenAIRE |
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