Naturally Occurring Isoleucyl-tRNA Synthetase without tRNA-dependent Pre-transfer Editing
| Autor: | Nikolina Sostaric, Boris Lenhard, Nevena Cvetesic, Ita Gruić-Sovulj, Morana Dulic, Mirna Bilus |
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| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
antibiotic resistance protein synthesis Biochemistry chemistry.chemical_compound RNA Transfer proofreading PSEUDOMONIC ACID Genetics biology tRNA-dependent pre-transfer editing 11 Medical And Health Sciences Genetic code AMINO-ACID ESCHERICHIA-COLI Protein Synthesis and Degradation Transfer RNA Proofreading Eukaryote 03 Chemical Sciences Life Sciences & Biomedicine STRUCTURAL BASIS Isoleucine-tRNA Ligase Biochemistry & Molecular Biology Isoleucine—tRNA ligase GENETIC-CODE MECHANISMS 03 medical and health sciences QUALITY-CONTROL Escherichia coli protein evolution Molecular Biology Gene mupirocin isoleucyl-tRNA synthetase pre-transfer editing eukaryotes Science & Technology COMPLEX Aminoacyl tRNA synthetase aminoacyl tRNA synthetase Genetic Complementation Test RECOGNITION Streptomyces griseus MUPIROCIN RESISTANCE Cell Biology 06 Biological Sciences biology.organism_classification transfer RNA (tRNA) 030104 developmental biology chemistry |
| Zdroj: | The Journal of Biological Chemistry |
| ISSN: | 1083-351X |
| Popis: | Isoleucyl-tRNA synthetase (IleRS) is unusual among aminoacyl-tRNA synthetases in having a tRNA-dependent pre-transfer editing activity. Alongside the typical bacterial IleRS (such as Escherichia coli IleRS), some bacteria also have the enzymes (eukaryote-like) that cluster with eukaryotic IleRSs and exhibit low sensitivity to the antibiotic mupirocin. Our phylogenetic analysis suggests that the ileS1 and ileS2 genes of contemporary bacteria are the descendants of genes that might have arisen by an ancient duplication event before the separation of bacteria and archaea. We present the analysis of evolutionary constraints of the synthetic and editing reactions in eukaryotic/eukaryote-like IleRSs, which share a common origin but diverged through adaptation to different cell environments. The enzyme from the yeast cytosol exhibits tRNA-dependent pre-transfer editing analogous to E. coli IleRS. This argues for the presence of this proofreading in the common ancestor of both IleRS types and an ancient origin of the synthetic site-based quality control step. Yet surprisingly, the eukaryote-like enzyme from Streptomyces griseus IleRS lacks this capacity; at the same time, its synthetic site displays the 10(3)-fold drop in sensitivity to antibiotic mupirocin relative to the yeast enzyme. The discovery that pre-transfer editing is optional in IleRSs lends support to the notion that the conserved post-transfer editing domain is the main checkpoint in these enzymes. We substantiated this by showing that under error-prone conditions S. griseus IleRS is able to rescue the growth of an E. coli lacking functional IleRS, providing the first evidence that tRNA-dependent pre-transfer editing in IleRS is not essential for cell viability. |
| Databáze: | OpenAIRE |
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