title: The structure of a mixed LNA/DNA:RNA duplex is driven by conformational coupling between LNA and deoxyribose residues as determined from 13C relaxation measurements.
abstract: A study of the internal dynamics of an LNA/DNA:RNA duplex has been performed to further characterize the conformational changes associated with the incorporation of locked nucleic acid (LNA) nucleotides in a DNA:RNA duplex. In general, it was demonstrated that the LNA/DNA:RNA duplex has a very high degree of order compared to dsDNA and dsRNA duplexes. The order parameters of the aromatic carbon atoms in the LNA/DNA strand are uniformly high, whereas a sharp drop in the degree of order was seen in the RNA strand in the beginning of the AUAU stretch in the middle of the strand. This can be related to a return to normal dsRNA dynamics for the central A:U base pair. The high order of the heteroduplex is consistent with preorganization of the chimera strand for an A-form duplex conformation. These results partly explain the dramatic increase in T(m) of the chimeric heteroduplex over dsDNA and DNA:RNA hybrids of the same sequence.
authors.affiliation: Nucleic Acid Center, Department of Chemistry, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
authors.forename: Katrine E
authors.initials: KE
authors.lastname: Nielsen
authors.forename: H Peter
authors.initials: HP
authors.lastname: Spielmann
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D003855:Deoxyribose / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides; D016376:Oligonucleotides, Antisense / Q000737:chemistry*; D012313:RNA / Q000737:chemistry*; D012330:RNA, Double-Stranded / Q000737:chemistry
chemical_list: D009841:Oligonucleotides; D016376:Oligonucleotides, Antisense; D012330:RNA, Double-Stranded; C477371:locked nucleic acid; D003855:Deoxyribose; D012313:RNA; D004247:DNA