title: Correlation of the guanosine exchangeable and nonexchangeable base protons in 13C-/15N-labeled RNA with an HNC-TOCSY-CH experiment.
abstract: A triple resonance HNC-TOCSY-CH experiment is described for correlating the guanosine imino proton and H8 resonances in 13C-/15N-labeled RNAs. Sequential assignment of the exchangeable imino protons in Watson-Crick base pairs is generally made independently of the assignment of the nonexchangeable base protons. This H(NC)-TOCSY-(C)H experiment makes it possible to unambiguously link the assignment of the guanosine H8 resonances with sequential assignment of the guanosine imino proton resonances. 2D H(NC)-TOCSY-(C)H spectra are presented for two isotopically labeled RNAs, a 30-nucleotide lead-dependent ribozyme known as the leadzyme, and a 48-nucleotide hammerhead ribozyme-RNA substrate complex. The results obtained on these two RNAs demonstrate that this HNC-TOCSY-CH experiment is an important tool for resonance assignment of isotopically labeled RNAs.
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado at Boulder 80309-0215, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Simorre
authors.forename: G R
authors.initials: GR
authors.lastname: Zimmermann
authors.forename: L
authors.initials: L
authors.lastname: Mueller
authors.forename: A
authors.initials: A
authors.lastname: Pardi
mesh_terms: D001483:Base Sequence; D002247:Carbon Isotopes; D006151:Guanosine / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008969:Molecular Sequence Data; D009587:Nitrogen Isotopes; D009690:Nucleic Acid Conformation; D011522:Protons; D016337:RNA, Catalytic / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D011522:Protons; D016337:RNA, Catalytic; D006151:Guanosine