title: Identification, localization, and relative quantitation of pseudouridine in RNA by tandem mass spectrometry of hydrolysis products.
abstract: The constitutional isomers uridine (U) and pseudouridine (Ψ) cannot be distinguished from each other by simple mass measurements of RNA or its fragments because the conversion of U into Ψ is a "mass-silent" post-transcriptional modification. Here we propose a new mass spectrometry based method for identification, localization, and relative quantitation of Ψ in RNA consisting of ∼20 nucleotides that does not require chemical labeling. Our approach takes advantage of the different fragmentation behavior of uridine (N-glycosidic bond) and pseudouridine (C-glycosidic bond) residues in RNA upon collisionally activated dissociation.
authors.affiliation: Institute of Organic Chemistry and Center for Molecular Biosciences (CMBI), University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria.
authors.forename: Monika
authors.initials: M
authors.lastname: Taucher
authors.forename: Barbara
authors.initials: B
authors.lastname: Ganisl
authors.forename: Kathrin
authors.initials: K
authors.lastname: Breuker