Two archaeal tRNase Z enzymes: similar but different
| Autor: | Annika Lieberoth, Stefanie V. Schütz, Bettina Späth, Susan Fischer, Florian Settele, Sylvia Schubert, Anita Marchfelder |
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| Rok vydání: | 2008 |
| Předmět: |
Archaeal Proteins
Endoribonuclease TRNA processing Electrophoretic Mobility Shift Assay RNA Archaeal Biochemistry Microbiology Potassium Chloride Substrate Specificity RNA Transfer Metals Heavy Endoribonucleases Escherichia coli RNA Precursors Genetics Cloning Molecular RNA Processing Post-Transcriptional Haloferax volcanii Molecular Biology chemistry.chemical_classification biology Thermophile General Medicine biology.organism_classification Pyrococcus furiosus DNA Archaeal Enzyme chemistry Phosphodiester bond Transfer RNA |
| Zdroj: | Archives of Microbiology. 190:301-308 |
| ISSN: | 1432-072X 0302-8933 |
| Popis: | The endoribonuclease tRNase Z plays an essential role in tRNA metabolism by removal of the 3' trailer element of precursor RNAs. To investigate tRNA processing in archaea, we identified and expressed the tRNase Z from Haloferax volcanii, a halophilic archaeon. The recombinant enzyme is a homodimer and efficiently processes precursor tRNAs. Although the protein is active in vivo at 2-4 M KCl, it is inhibited by high KCl concentrations in vitro, whereas 2-3 M (NH4)(2)SO4 do not inhibit tRNA processing. Analysis of the metal content of the metal depleted tRNase Z revealed that it still contains 0.4 Zn2+ ions per dimer. In addition tRNase Z requires Mn2+ ions for processing activity. We compared the halophilic tRNase Z to the homologous one from Pyrococcus furiosus, a thermophilic archaeon. Although both enzymes have 46% sequence similarity, they differ in their optimal reaction conditions. Both archaeal tRNase Z proteins process mitochondrial pre-tRNAs. Only the thermophilic tRNase Z shows in addition activity toward intron containing pre-tRNAs, 5' extended precursors, the phosphodiester bis(p-nitrophenyl)phosphate (bpNPP) and the glyoxalase II substrate S-D-lactoylglutathion (SLG). |
| Databáze: | OpenAIRE |
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