title: Disintegration of cruciform and G-quadruplex structures during the course of helicase-dependent amplification (HDA).
abstract: Unlike chemical damages on DNA, physical alterations of B-form of DNA occur commonly in organisms that serve as signals for specified cellular events. Although the modes of action for repairing of chemically damaged DNA have been well studied nowadays, the repairing mechanisms for physically altered DNA structures have not yet been understood. Our current in vitro studies show that both breakdown of stable non-B DNA structures and resumption of canonical B-conformation of DNA can take place during the courses of isothermal helicase-dependent amplification (HDA). The pathway that makes the non-B DNA structures repairable is presumably the relieving of the accumulated torsional stress that was caused by the positive supercoiling. Our new findings suggest that living organisms might have evolved this distinct and economical pathway for repairing their physically altered DNA structures.
authors: Key Lab of Forest Genetics and Biotechnology, Nanjing Forestry University, 159 Longpan Road, Nanjing 210037, China; Division of Chemistry and Biological Chemistry, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore, Singapore. Electronic address: lida0006@e.ntu.edu.sg.
authors: Dawei
authors: D
authors: Li
authors: Division of Chemistry and Biological Chemistry, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore, Singapore.
authors: Bei
authors: B
authors: Lv
authors: Division of Chemistry and Biological Chemistry, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore, Singapore.
authors: Hao
authors: H
authors: Zhang
authors: Division of Chemistry and Biological Chemistry, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore, Singapore.
authors: Jasmine Yiqin
authors: JY
authors: Lee
authors: Division of Chemistry and Biological Chemistry, Nanyang Technological University, 21 Nanyang Link, 637371 Singapore, Singapore. Electronic address: thli@ntu.edu.sg.
authors: Tianhu
authors: T
authors: Li
mesh_terms: D004249:DNA Damage; D004265:DNA Helicases / Q000378:metabolism*; D004261:DNA Replication; D059371:DNA, B-Form / Q000737:chemistry / Q000378:metabolism; D045566:DNA, Cruciform / Q000737:chemistry* / Q000378:metabolism; D054856:G-Quadruplexes; D018625:Microscopy, Atomic Force; D009690:Nucleic Acid Conformation
chemical_list: D059371:DNA, B-Form; D045566:DNA, Cruciform; D004265:DNA Helicases
keywords: Cruciform; DNA replication; G-quadruplex; Helicase; Positive supercoiling