title: Salt-dependent intra- and internucleosomal interactions of the H3 tail domain in a model oligonucleosomal array.
abstract: The core histone tail domains are known to be key regulators of chromatin structure and function. The tails are required for condensation of nucleosome arrays into secondary and tertiary chromatin structures, yet little is known regarding tail structures or sites of tail interactions in chromatin. We have developed a system to test the hypothesis that the tails participate in internucleosomal interactions during salt-dependent chromatin condensation, and here we used it to examine interactions of the H3 tail domain. We found that the H3 tail participates primarily in intranucleosome interactions when the nucleosome array exists in an extended "beads-on-a-string" conformation and that tail interactions reorganize to engage in primarily internucleosome interactions as the array successively undergoes salt-dependent folding and oligomerization. These results indicated that the location and interactions of the H3 tail domain are dependent upon the degree of condensation of the nucleosomal array, suggesting a mechanism by which alterations in tail interactions may elaborate different structural and functional states of chromatin.
authors.affiliation: Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA.
authors.forename: Chunyang
authors.initials: C
authors.lastname: Zheng
authors.forename: Xu
authors.initials: X
authors.lastname: Lu
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Hansen
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Hayes
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D001665:Binding Sites; D003432:Cross-Linking Reagents / Q000494:pharmacology; D003545:Cysteine / Q000378:metabolism; D004247:DNA / Q000235:genetics; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D006657:Histones / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology; D008954:Models, Biological; D008956:Models, Chemical; D009707:Nucleosomes / Q000378:metabolism*; D010761:Phosphorus Radioisotopes; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012694:Serine / Q000737:chemistry; D012965:Sodium Chloride / Q000378:metabolism*; D013698:Templates, Genetic; D014466:Ultraviolet Rays; D014981:Xenopus
chemical_list: D003432:Cross-Linking Reagents; D006657:Histones; D009707:Nucleosomes; D010761:Phosphorus Radioisotopes; D011994:Recombinant Proteins; D012965:Sodium Chloride; D012694:Serine; D004247:DNA; D008274:Magnesium; D003545:Cysteine