title: Specific contributions of histone tails and their acetylation to the mechanical stability of nucleosomes.
abstract: The distinct contributions of histone tails and their acetylation to nucleosomal stability were examined by mechanical disruption of individual nucleosomes in a single chromatin fiber using an optical trap. Enzymatic removal of H2A/H2B tails primarily decreased the strength of histone-DNA interactions located approximately +/-36bp from the dyad axis of symmetry (off-dyad strong interactions), whereas removal of the H3/H4 tails played a greater role in regulating the total amount of DNA bound. Similarly, nucleosomes composed of histones acetylated to different degrees by the histone acetyltransferase p300 exhibited significant decreases in the off-dyad strong interactions and the total amount of DNA bound. Acetylation of H2A/H2B appears to play a particularly critical role in weakening the off-dyad strong interactions. Collectively, our results suggest that the destabilizing effects of tail acetylation may be due to elimination of specific key interactions in the nucleosome.
authors.affiliation: Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Brent
authors.initials: B
authors.lastname: Brower-Toland
authors.forename: David A
authors.initials: DA
authors.lastname: Wacker
authors.forename: Robert M
authors.initials: RM
authors.lastname: Fulbright
authors.forename: John T
authors.initials: JT
authors.lastname: Lis
authors.forename: W Lee
authors.initials: WL
authors.lastname: Kraus
authors.forename: Michelle D
authors.initials: MD
authors.lastname: Wang
mesh_terms: D000107:Acetylation; D000595:Amino Acid Sequence; D004247:DNA / Q000378:metabolism; D005786:Gene Expression Regulation; D006657:Histones / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D046228:Microarray Analysis; D008969:Molecular Sequence Data; D009707:Nucleosomes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D013816:Thermodynamics; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D006657:Histones; D009707:Nucleosomes; D004247:DNA