title: FAD/folate-dependent tRNA methyltransferase: flavin as a new methyl-transfer agent.
abstract: RNAs contain structurally and functionally important modified nucleosides. Methylation, the most frequent RNA modification in all living organisms, mostly relies on SAM (S-adenosylmethionine)-dependent methyltransferases. TrmFO was recently discovered as a unique tRNA methyltransferase using instead methylenetetrahydrofolate and reduced flavin adenine dinucleotide (FAD) as essential cofactors, but its mechanism has remained elusive. Here, we report that TrmFO carries an active tRNA-methylating agent and characterize it as an original enzyme-methylene-FAD covalent adduct by mass spectrometry and a combination of spectroscopic and biochemical methods. Our data support a novel tRNA methylating mechanism.
authors.affiliation: Laboratoire de Chimie des Processus Biologiques, CNRS-FRE 3488, Collège De France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France. djemel.hamdane@college-de-france.fr
authors.forename: Djemel
authors.initials: D
authors.lastname: Hamdane
authors.forename: Manuela
authors.initials: M
authors.lastname: Argentini
authors.forename: David
authors.initials: D
authors.lastname: Cornu
authors.forename: Béatrice
authors.initials: B
authors.lastname: Golinelli-Pimpaneau
authors.forename: Marc
authors.initials: M
authors.lastname: Fontecave
mesh_terms: D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry*; D005415:Flavins / Q000737:chemistry*; D005492:Folic Acid / Q000737:chemistry*; D013058:Mass Spectrometry; D015394:Molecular Structure; D011994:Recombinant Proteins / Q000235:genetics; D012359:tRNA Methyltransferases / Q000737:chemistry*
chemical_list: D005415:Flavins; D011994:Recombinant Proteins; D005182:Flavin-Adenine Dinucleotide; D005492:Folic Acid; D012359:tRNA Methyltransferases