title: Structure of the beta-form of poly d(A).poly d(U).
abstract: The crystalline beta-form of the sodium salt of poly d(A).poly d(U) trapped in oriented fibers forms a Watson-Crick base-paired, 10(1) double-helix of pitch 3.2 nm. Two molecules are present in a monoclinic unit cell apparently isomorphous with beta-poly d(A).poly d(T). The two chains in each molecule both carry C2'-endo puckered furanose rings but are conformationally not identical. The orientations of the A:U base-pairs relative to the helix-axis are distinctly different from those in classical B-DNA and the overall morphology of the duplex in which they reside resembles that of the alpha-forms of poly (purine).poly (pyrimidine) DNA duplexes previously reported.
authors.affiliation: Whistler Center, Purdue University West Lafayette, Indiana 47907.
authors.forename: R
authors.initials: R
authors.lastname: Chandrasekaran
authors.forename: A
authors.initials: A
authors.lastname: Radha
authors.forename: H S
authors.initials: HS
authors.lastname: Park
authors.forename: S
authors.initials: S
authors.lastname: Arnott
mesh_terms: D004247:DNA; D006860:Hydrogen Bonding; D008958:Models, Molecular; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D011061:Poly A; D011072:Poly U; D014961:X-Ray Diffraction
chemical_list: D011061:Poly A; C015465:poly(dA); D011072:Poly U; D004247:DNA