title: Complex kinetics of DNA condensation revealed through DNA twist tracing.
abstract: Toroid formation is an important mechanism for DNA condensation in cells. The length change during DNA condensation was investigated in previous single-molecule experiments. However, DNA twist is key to understanding the topological kinetics of DNA condensation. In this study, DNA twist as well as DNA length was traced during the DNA condensation by the freely orbiting magnetic tweezers and the tilted magnetic tweezers combined with Brownian dynamics simulations. The experimental results disclose the complex relationship between DNA extension and backbone rotation. Brownian dynamics simulations show that the toroid formation follows a wiggling pathway which leads to the complex DNA backbone rotation as revealed in our experiments. These findings provide the complete description of multivalent cation-dependent DNA toroid formation under tension.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Physics, National University of Singapore, Singapore 117542.|Mechanobiology Institute, National University of Singapore, Singapore 117411.
authors.forename: Wei Juan
authors.initials: WJ
authors.lastname: Wong
authors.affiliation: Department of Physics, National University of Singapore, Singapore 117542.|Mechanobiology Institute, National University of Singapore, Singapore 117411.
authors.forename: Ci Ji
authors.initials: CJ
authors.lastname: Lim
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Hai-Peng
authors.initials: HP
authors.lastname: Ju
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Physics, National University of Singapore, Singapore 117542.|Mechanobiology Institute, National University of Singapore, Singapore 117411.
authors.forename: Jie
authors.initials: J
authors.lastname: Yan
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Peng-Ye
authors.initials: PY
authors.lastname: Wang
mesh_terms: D003198:Computer Simulation; D004247:DNA / Q000737:chemistry*; D004076:Digoxigenin / Q000737:chemistry; D007700:Kinetics; D016014:Linear Models; D008956:Models, Chemical; D008957:Models, Genetic; D009690:Nucleic Acid Conformation; D012399:Rotation; D055672:Static Electricity; D019809:Streptavidin / Q000737:chemistry
chemical_list: D004247:DNA; D019809:Streptavidin; D004076:Digoxigenin