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Archaeal fibrillarin–Nop5 heterodimer 2′-O-methylates RNA independently of the C/D guide RNP particle

Archaeal fibrillarin (aFib) is a well-characterized S-adenosyl methionine (SAM)-dependent RNA 2′-O-methyltransferase that is known to act in a large C/D ribonucleoprotein (RNP) complex together with Nop5 and L7Ae proteins and a box C/D guide RNA. In the reaction, the guide RNA serves to direct the m...

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Detalles Bibliográficos
Autores principales: Tomkuvienė, Miglė, Ličytė, Janina, Olendraitė, Ingrida, Liutkevičiūtė, Zita, Clouet-d'Orval, Béatrice, Klimašauskas, Saulius
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Cold Spring Harbor Laboratory Press 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5558902/
https://www.ncbi.nlm.nih.gov/pubmed/28576826
http://dx.doi.org/10.1261/rna.059832.116
Descripción
Sumario:Archaeal fibrillarin (aFib) is a well-characterized S-adenosyl methionine (SAM)-dependent RNA 2′-O-methyltransferase that is known to act in a large C/D ribonucleoprotein (RNP) complex together with Nop5 and L7Ae proteins and a box C/D guide RNA. In the reaction, the guide RNA serves to direct the methylation reaction to a specific site in tRNA or rRNA by sequence complementarity. Here we show that a Pyrococcus abyssi aFib–Nop5 heterodimer can alone perform SAM-dependent 2′-O-methylation of 16S and 23S ribosomal RNAs in vitro independently of L7Ae and C/D guide RNAs. Using tritium-labeling, mass spectrometry, and reverse transcription analysis, we identified three in vitro 2′-O-methylated positions in the 16S rRNA of P. abyssi, positions lying outside of previously reported pyrococcal C/D RNP methylation sites. This newly discovered stand-alone activity of aFib–Nop5 may provide an example of an ancestral activity retained in enzymes that were recruited to larger complexes during evolution.