title: Single-molecule studies on the mechanical interplay between DNA supercoiling and H-NS DNA architectural properties.
abstract: The Escherichia coli H-NS protein is a major nucleoid-associated protein that is involved in chromosomal DNA packaging and gene regulatory functions. These biological processes are intimately related to the DNA supercoiling state and thus suggest a direct relationship between H-NS binding and DNA supercoiling. Here, we show that H-NS, which has two distinct DNA-binding modes, is able to differentially regulate DNA supercoiling. H-NS DNA-stiffening mode caused by nucleoprotein filament formation is able to suppress DNA plectoneme formation during DNA supercoiling. In contrast, when H-NS is in its DNA-bridging mode, it is able to promote DNA plectoneme formation during DNA supercoiling. In addition, the DNA-bridging mode is able to block twists diffusion thus trapping DNA in supercoiled domains. Overall, this work reveals the mechanical interplay between H-NS and DNA supercoiling which provides insights to H-NS organization of chromosomal DNA based on its two distinct DNA architectural properties.
authors.affiliation: Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore Centre for Bioimaging Sciences, National University of Singapore, Singapore Mechanobiology Institute, Singapore Department of Physics, National University of Singapore, Singapore.
authors.forename: Ci Ji
authors.initials: CJ
authors.lastname: Lim
authors.affiliation: Mechanobiology Institute, Singapore Jesse Brown Veterans Affairs Medical Center, Chicago, IL, USA Department of Microbiology & Immunology, University of Illinois-Chicago, Chicago, IL, USA Department of Biological Sciences, National University of Singapore, Singapore.
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Kenney
authors.affiliation: Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore Centre for Bioimaging Sciences, National University of Singapore, Singapore Mechanobiology Institute, Singapore Department of Physics, National University of Singapore, Singapore phyyj@nus.edu.sg.
authors.forename: Jie
authors.initials: J
authors.lastname: Yan
mesh_terms: D001696:Biomechanical Phenomena; D004278:DNA, Superhelical / Q000737:chemistry* / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D036781:Fimbriae Proteins / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D004278:DNA, Superhelical; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C529458:FimG protein, E coli; D036781:Fimbriae Proteins