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An oligodeoxyribonucleotide N3'--> P5' phosphoramidate duplex forms an A-type helix in solution.

D Ding·S M Grayaznov·D H Lloyd·S Chandrasekaran·S Yao·L Ratmeyer·Y Pan·W D Wilson
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Abstract

The solution conformations of the dinucleotide d(TT) and the modified duplex d(CGCGAATTCGCG)2 with N3'--> P5' phosphoramidate internucleoside linkages have been studied using circular dichroism (CD) and NMR spectroscopy. The CD spectra indicate that the duplex conformation is similar to that of isosequential phosphodiester RNA, a A-type helix, and is different from that of DNA, a B-type helix, NMR studies of model dimers d(TpT) and N3'--> P5' phosphoramidate d(TnpT) show that the sugar ring conformation changes from predominantly C2'-endo to C3'-endo when the 3'-phosphoester is replaced by a phosphoramidate group. Two-dimensional NMR (NOESY, DQF-COSY and TOCSY spectra) studies of the duplex provide additional details about the A-type duplex conformation of the oligonucleotide phosphoramidate and confirm that all furanose rings of 3'-aminonucleotides adopt predominantly N-type sugar puckering.

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Base SequenceCircular DichroismDeoxyriboseMagnetic Resonance SpectroscopyMolecular Sequence DataNucleic Acid ConformationNucleic Acid DenaturationOligodeoxyribonucleotidesRNAJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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D Ding, S M Grayaznov, D H Lloyd, S Chandrasekaran, S Yao, L Ratmeyer, Y Pan, W D Wilson. 1996-01-15. An oligodeoxyribonucleotide N3'--> P5' phosphoramidate duplex forms an A-type helix in solution.. https://doi.org/10.1093/nar%2F24.2.354

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