The ribosome assembly factor Nep1 responsible for Bowen–Conradi syndrome is a pseudouridine-N1-specific methyltransferase
| Autor: | Jens Wöhnert, Ute Bahr, Alexander Heckel, Michael Karas, Olga Frolow, Martin Held, Britta Meyer, Joachim W. Engels, Karl-Dieter Entian, Jan Philip Wurm, Peter Kötter |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
Methyltransferase
Archaeal Proteins Ribosome biogenesis Biology medicine.disease_cause Methylation Pseudouridine Ribosome assembly chemistry.chemical_compound Two-Hybrid System Techniques ddc:570 Consensus Sequence Genetics medicine Humans Nuclear Magnetic Resonance Biomolecular Mutation Binding Sites Base Sequence Oligonucleotide Nucleic Acid Enzymes Methanococcales RNA Methanocaldococcus jannaschii Nuclear Proteins RNA-Binding Proteins RNA Fungal Methyltransferases biology.organism_classification Molecular biology Spectrometry Fluorescence Biochemistry chemistry RNA Ribosomal |
| Zdroj: | Nucleic Acids Research |
| Popis: | Nep1 (Emg1) is a highly conserved nucleolar protein with an essential function in ribosome biogenesis. A mutation in the human Nep1 homolog causes Bowen-Conradi syndrome-a severe developmental disorder. Structures of Nep1 revealed a dimer with a fold similar to the SPOUT-class of RNA-methyltransferases suggesting that Nep1 acts as a methyltransferase in ribosome biogenesis. The target for this putative methyltransferase activity has not been identified yet. We characterized the RNA-binding specificity of Methanocaldococcus jannaschii Nep1 by fluorescence- and NMR-spectroscopy as well as by yeast three-hybrid screening. Nep1 binds with high affinity to short RNA oligonucleotides corresponding to nt 910-921 of M. jannaschii 16S rRNA through a highly conserved basic surface cleft along the dimer interface. Nep1 only methylates RNAs containing a pseudouridine at a position corresponding to a previously identified hypermodified N1-methyl-N3-(3-amino-3-carboxypropyl) pseudouridine (m1acp3-Psi) in eukaryotic 18S rRNAs. Analysis of the methylated nucleoside by MALDI-mass spectrometry, HPLC and NMR shows that the methyl group is transferred to the N1 of the pseudouridine. Thus, Nep1 is the first identified example of an N1-specific pseudouridine methyltransferase. This enzymatic activity is also conserved in human Nep1 suggesting that Nep1 is the methyltransferase in the biosynthesis of m1acp3-Psi in eukaryotic 18S rRNAs. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|