title: Spatial configuration of ordered polynucleotide chains: a novel double helix.
abstract: Structural details are reported for a novel right-handed polynucleotide double helix stabilized by vertical base stacking and hydrogen bonding. The primary difference between this duplex and the familiar Watson-Crick horizontally stabilized polynucleotide complex arises in the glycosyl rotation of the heterocyclic bases with respect to the sugar-phate backbone. In the vertical double helix the bases adopt a fairly unusual (although not sterically impossible) high-anti conformation, while in the horizontal models deduced from x-ray analyses the bases occur in the favored anti arrangement. The base pairing scheme in both duplexes is the standard Watson-Crick type. The vertical double helix is demonstrated to be a plausible model for the unusual complex formation observed between complementary synthetic polycyclonucleotides (the bases of which are fixed by a chemical linkage in the high-anti orientation) and also a potential alternative ordered structure available to naturally occurring nucleic acid systems that can adopt both anti and high-anti glycosyl arrangements.
mesh_terms: D003201:Computers; D006860:Hydrogen Bonding; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009712:Nucleotides, Cyclic; D011063:Poly A-U; D013237:Stereoisomerism
chemical_list: D009712:Nucleotides, Cyclic; D011063:Poly A-U
references.citation: Nucleic Acids Res. 1976 Aug;3(8):1973-84
references.pmid: 184437
references.citation: Nucleic Acids Res. 1975 Dec;2(12):2329-41
references.pmid: 802512
references.citation: Nat New Biol. 1973 Jul 25;244(134):99-101
references.pmid: 4515922
references.citation: Biopolymers. 1976 May;15(5):859-78
references.pmid: 1260107
references.citation: J Am Chem Soc. 1974 Jul 24;96(15):4966-72
references.pmid: 4853692
references.citation: J Am Chem Soc. 1974 Aug 7;96(16):5276-8
references.pmid: 4855456
references.citation: Biopolymers. 1973;12(8):1787-814
references.pmid: 4733709
references.citation: Biochemistry. 1973 Mar 13;12(6):1196-202
references.pmid: 4688865
references.citation: J Am Chem Soc. 1973 Jun 13;95(12):4054-6
references.pmid: 4710066
references.citation: J Am Chem Soc. 1972 Dec 27;94(26):9189-93
references.pmid: 4642368
references.citation: J Am Chem Soc. 1972 Jul 26;94(15):5480-6
references.pmid: 5040853
references.citation: J Mol Biol. 1972 Jun 28;67(3):375-96
references.pmid: 5045303
references.citation: Nucleic Acids Res. 1975 Sep;2(9):1629-37
references.pmid: 1101229
references.citation: Biochem Biophys Res Commun. 1976 Jan 12;68(1):89-96
references.pmid: 1108880
references.citation: Nucleic Acids Res. 1976 Apr;3(4):1111-23
references.pmid: 775444
references.citation: J Am Chem Soc. 1976 Aug 18;98(17):5371-80
references.pmid: 956562
references.citation: Nucleic Acids Res. 1976 Mar;3(3):729-47
references.pmid: 1272796
references.citation: Biochem Biophys Res Commun. 1976 Apr 19;69(4):979-87
references.pmid: 1275929
references.citation: J Am Chem Soc. 1976 Feb 18;98(4):969-73
references.pmid: 1245708