title: Annealed random copolymer model of the B-Z transition in DNA: torsional responses.
abstract: Both in vivo and in vitro, specific sequences in double-stranded DNA can adopt the left-handed Z-form when underwound. Recently, the B-Z transition of DNA has been studied in detail in magnetic tweezers experiments by several groups. We present a theoretical description of this transition, based on an annealed random copolymer model. The transition of a switchable sequence is discussed as a function of energetic and geometric parameters of the B- and Z-forms, of the applied boundary conditions, and of the characteristics of the B-Z interface. We address a possible torsional softening upon the B-Z transition. The model can be also applied to other biofilaments with annealed torsional/flexural degrees of freedom.
authors.affiliation: Department of Physics, Sejong University, Seoul, South Korea.
authors.forename: Ah-Young
authors.initials: AY
authors.lastname: Kwon
authors.affiliation: Department of Physics, Sejong University, Seoul, South Korea; Institute Charles Sadron, Centre National de la Recherche Scientifique, Strasbourg, France. Electronic address: lee@sejong.ac.kr.
authors.forename: Nam-Kyung
authors.initials: NK
authors.lastname: Lee
authors.affiliation: Department of Physics, Korea University, Seoul, South Korea.
authors.forename: Seok-Cheol
authors.initials: SC
authors.lastname: Hong
authors.affiliation: Institute Charles Sadron, Centre National de la Recherche Scientifique, Strasbourg, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Fierling
authors.affiliation: Department of Physics, Sejong University, Seoul, South Korea; Institute Charles Sadron, Centre National de la Recherche Scientifique, Strasbourg, France.
authors.forename: Albert
authors.initials: A
authors.lastname: Johner
mesh_terms: D059371:DNA, B-Form / Q000737:chemistry*; D043542:DNA, Z-Form / Q000737:chemistry*; D008956:Models, Chemical; D058105:Polymerization; D054159:Torsion, Mechanical
chemical_list: D059371:DNA, B-Form; D043542:DNA, Z-Form