title: Stretching of homopolymeric RNA reveals single-stranded helices and base-stacking.
abstract: We have found strong supporting evidence for the helical structures of single-stranded nucleic acids by stretching individual molecules of polyadenylic acid [poly(A)] and polycytidylic acid [poly(C)]. Analyzing the force versus extension data using a two-state elastic model in which random-coil domains alternate with rigid helical domains allows one to extract the thermodynamic and structural properties. In addition, it also yields moderate to low cooperativity of the helix-coil transition for poly(A) and poly(C), respectively.
authors.affiliation: Department of Physics, University of Arizona, Arizona 85721, USA.
authors.forename: Yeonee
authors.initials: Y
authors.lastname: Seol
authors.forename: Gary M
authors.initials: GM
authors.lastname: Skinner
authors.forename: Koen
authors.initials: K
authors.lastname: Visscher
authors.forename: Arnaud
authors.initials: A
authors.lastname: Buhot
authors.forename: Avraham
authors.initials: A
authors.lastname: Halperin
mesh_terms: D004548:Elasticity; D008956:Models, Chemical; D009690:Nucleic Acid Conformation; D011061:Poly A / Q000737:chemistry*; D011066:Poly C / Q000737:chemistry*; D012313:RNA / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D011061:Poly A; D011066:Poly C; D012313:RNA