title: Stretched DNA investigated using molecular-dynamics and quantum-mechanical calculations.
abstract: We combined atomistic molecular-dynamics simulations with quantum-mechanical calculations to investigate the sequence dependence of the stretching behavior of duplex DNA. Our combined quantum-mechanical/molecular-mechanical approach demonstrates that molecular-mechanical force fields are able to describe both the backbone and base-base interactions within the highly distorted nucleic acid structures produced by stretching the DNA from the 5' ends, which include conformations containing disassociated basepairs, just as well as these force fields describe relaxed DNA conformations. The molecular-dynamics simulations indicate that the force-induced melting pathway is sequence-dependent and is influenced by the availability of noncanonical hydrogen-bond interactions that can assist the disassociation of the DNA basepairs. The biological implications of these results are discussed.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Rezác
authors.forename: Pavel
authors.initials: P
authors.lastname: Hobza
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Harris
mesh_terms: D003198:Computer Simulation; D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure*; D055119:Elastic Modulus; D007700:Kinetics; D008956:Models, Chemical; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D011789:Quantum Theory; D013314:Stress, Mechanical
chemical_list: D004247:DNA