title: Novel 2D and 3D multiple-quantum bi-directional HCNCH experiments for the correlation of ribose and base protons/carbons in 13C/15N labeled RNA.
abstract: Multiple-quantum 2D and 3D bi-directional HCNCH experiments are presented for the correlation of base and ribose protons/carbons in 13C/15N labeled HIV-1 TAR RNA. In both 2D and 3D experiments, the magnetization of H1' is transferred to H6/H8 and H1' through H1'-C1'-N1/9-C6/8-H6/8 and H1'-C1'-N1/9-C1'-H1' pathways, and the magnetization of H6/8 is transferred to H1' and H6/8 through H6/8-C6/8-N1/9-C1'-H1' and H6/8-C6/8-N1/9-C6/8-H6/8 pathways. Chemical shifts of four different nuclei (H1', C1', C6/8 and H6/8) are sampled in the 2D experiment. The correlation of base and ribose protons/carbons is established by the rectangular arrangement of crossover and out-and-back peaks in the proton/carbon correlated spectrum. The rectangular connections can be further resolved using the nitrogen dimension in a 1H/13C/15N 3D experiment. Furthermore, by taking advantage of the well separated chemical shifts of N1 (pyrimidine) and N9 (purine), the 2D spectrum can be simplified into two sub-spectra based on their base type. Both experiments were tested on a 13C/15N labeled 27-mer HIV-1 TAR RNA containing a UUCG hairpin loop.
authors.affiliation: Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA. weidong@sbnmrl.ski.mskcc.org
authors.forename: W
authors.initials: W
authors.lastname: Hu
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Gosser
authors.forename: W
authors.initials: W
authors.lastname: Xu
authors.forename: D J
authors.initials: DJ
authors.lastname: Patel
mesh_terms: D002247:Carbon Isotopes; D016325:HIV Long Terminal Repeat; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011522:Protons; D012313:RNA / Q000737:chemistry*; D012367:RNA, Viral / Q000737:chemistry; D012266:Ribose / Q000737:chemistry
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D011522:Protons; D012367:RNA, Viral; D012313:RNA; D012266:Ribose