High-resolution biophysical analysis of the dynamics of nucleosome formation.
We describe a biophysical approach that enables changes in the structure of DNA to be followed during nucleosome formation in in vitro reconstitution with either the canonical "Widom" sequence or a judiciously mutated sequence. The rapid non-perturbing photochemical analysis presented here provides 'snapshots' of the DNA configuration at any given moment in time during nucleosome formation under a very broad range of reaction conditions. Changes in DNA photochemical reactivity upon protein binding are interpreted as being mainly induced by alterations in individual base pair roll angles. The results strengthen the importance of the role of an initial (H3/H4)2 histone tetramer-DNA interaction and highlight the modulation of this early event by the DNA sequence. (H3/H4)2 binding precedes and dictates subsequent H2A/H2B-DNA interactions, which are less affected by the DNA sequence, leading to the final octameric nucleosome. Overall, our results provide a novel, exciting way to investigate those biophysical properties of DNA that constitute a crucial component in nucleosome formation and stabilization.
LBPA, IDA, ENS Cachan, CNRS, Université Paris-Saclay, F-94235, Cachan, France.
Akiko
A
Hatakeyama
LBPA, IDA, ENS Cachan, CNRS, Université Paris-Saclay, F-94235, Cachan, France.
Brigitte
B
Hartmann
MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus Cambridge, CB2 0QH, UK.|Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1GA, UK.
Andrew
A
Travers
LBPA, IDA, ENS Cachan, CNRS, Université Paris-Saclay, F-94235, Cachan, France.
Claude
C
Nogues
LBPA, IDA, ENS Cachan, CNRS, Université Paris-Saclay, F-94235, Cachan, France.
Malcolm
M
Buckle
D055592:Biophysical Phenomena; D055598:Chemical Phenomena; D004247:DNA / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D006801:Humans; D009707:Nucleosomes / Q000378:metabolism* / Q000648:ultrastructure*; D011485:Protein Binding
D006657:Histones; D009707:Nucleosomes; D004247:DNA