H3 and H4 histone tails play a central role in the interactions of recombinant NCPs.
Using small-angle x-ray scattering, we probe the effect of histone tails on both internucleosomal interactions and nucleosome conformation. To get insight into the specific role of H3 and H4 histone tails, perfectly monodisperse recombinant nucleosome core particles were reconstituted, either intact or deprived of both H3 and H4 histone tails (gH3gH4). The main result is that H3 and H4 histone tails are necessary to induce attractive interactions between NCPs. A pair potential model was used to describe interactions between NCPs. At all salt concentrations, interactions between gH3gH4 NCPs are best described by repulsive interactions exclusively. For intact NCPs, an additional attractive term, with a 5-10 kT magnitude and 20 A range, is required to account for interparticle interactions above 50 mM monovalent salt. Regarding conformation, intact NCPs in solution are similar to NCPs in 3D crystals. gH3gH4 NCPs instead give rise to slightly different small-angle x-ray scattering curves that can be understood as a more opened conformation of the particle, where DNA ends are slightly detached from the core.
Bertin
Aurélie
A
Laboratoire de Physique des Solides, Centre National de la Recherche Scientifique, UMR 8502, Université Paris-Sud, 91405 Orsay Cédex, France. bertin@berkeley.edu
Renouard
Madalena
M
Pedersen
Jan Skov
JS
Livolant
Françoise
F
Durand
Dominique
D
D001665:Binding Sites; D003198:Computer Simulation; D006657:Histones / Q000737:chemistry* / Q000648:ultrastructure*; D008956:Models, Chemical; D008958:Models, Molecular; D009707:Nucleosomes / Q000737:chemistry* / Q000648:ultrastructure*; D011485:Protein Binding; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000648:ultrastructure
D006657:Histones; D009707:Nucleosomes; D011994:Recombinant Proteins