Atomic force microscopy imaging of SWI/SNF action: mapping the nucleosome remodeling and sliding.
We propose a combined experimental (atomic force microscopy) and theoretical study of the structural and dynamical properties of nucleosomes. In contrast to biochemical approaches, this method allows us to determine simultaneously the DNA-complexed length distribution and nucleosome position in various contexts. First, we show that differences in the nucleoproteic structure observed between conventional H2A and H2A.Bbd variant nucleosomes induce quantitative changes in the length distribution of DNA-complexed with histones. Then, the sliding action of remodeling complex SWI/SNF is characterized through the evolution of the nucleosome position and wrapped DNA length mapping. Using a linear energetic model for the distribution of DNA-complexed length, we extract the net-wrapping energy of DNA onto the histone octamer and compare it to previous studies.
Montel
Fabien
F
Laboratoire Joliot-Curie (CNRS USR 3010) et Laboratoire de Physique (CNRS UMR 5672), Ecole Normale Supérieure de Lyon, 69007 Lyon, France.
Fontaine
Emeline
E
St-Jean
Philippe
P
Castelnovo
Martin
M
Faivre-Moskalenko
Cendrine
C
D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D042002:Chromatin Assembly and Disassembly; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D006657:Histones / Q000737:chemistry / Q000378:metabolism; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D018625:Microscopy, Atomic Force; D008954:Models, Biological; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism*; D009707:Nucleosomes / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism*; D014982:Xenopus laevis
D006657:Histones; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D009707:Nucleosomes; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D004247:DNA