Discovery of epoxyqueuosine (oQ) reductase reveals parallels between halorespiration and tRNA modification
| Autor: | Gabriella Molnar, Zachary D. Miles, Reid M. McCarty, Vahe Bandarian |
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| Rok vydání: | 2011 |
| Předmět: |
TRNA modification
Queuosine Reductase Biology medicine.disease_cause Mass Spectrometry Gene Knockout Techniques chemistry.chemical_compound RNA Transfer Biosynthesis Escherichia coli Nucleoside Q medicine Cloning Molecular Gene DNA Primers Multidisciplinary Molecular Structure Computational Biology RNA Biological Sciences Vitamin B 12 chemistry Biochemistry Transfer RNA Oxidoreductases Bacillus subtilis Chromatography Liquid |
| Zdroj: | Proceedings of the National Academy of Sciences. 108:7368-7372 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.1018636108 |
| Popis: | Transfer RNA is one of the most richly modified biological molecules. Biosynthetic pathways that introduce these modifications are underexplored, largely because their absence does not lead to obvious phenotypes under normal growth conditions. Queuosine (Q) is a hypermodified base found in the wobble positions of tRNA Asp, Asn, His, and Tyr from bacteria to mankind. Using liquid chromatography MS methods, we have screened 1,755 single gene knockouts of Escherichia coli and have identified the key final step in the biosynthesis of Q. The protein is homologous to B 12 -dependent iron-sulfur proteins involved in halorespiration. The recombinant Bacillus subtilis epoxyqueuosine (oQ) reductase catalyzes the conversion of oQ to Q in a synthetic substrate, as well as undermodified RNA isolated from an oQ reductase knockout strain. The activity requires inclusion of a reductant and a redox mediator. Finally, exogenously supplied cobalamin stimulates the activity. This work provides the framework for studies of the biosynthesis of other modified RNA components, where lack of accessible phenotype or obvious gene clustering has impeded discovery. Moreover, discovery of the elusive oQ reductase protein completes the biosynthetic pathway of Q. |
| Databáze: | OpenAIRE |
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