title: Trinucleosome compaction studied by fluorescence energy transfer and scanning force microscopy.
abstract: The effect of the salt concentration, linker histone H1, and histone acetylation on the structure of trinucleosomes reconstituted on a 608 bp DNA containing one centered nucleosome positioning signal was studied. Fluorescence resonance energy transfer (FRET) in solution and scanning force microscopy (SFM) measurements in liquid were done on the same samples. The distance between the DNA ends decreases under the effect of an increasing salt concentration and also by the incorporation of the H1 linker histone. A decrease of internucleosomal center-to-center (cc) distances by H1 was observed that was limited to a minimal value of about 20 nm. The distribution of the angle formed between consecutive nucleosomes was narrowed by H1. The effect of acetylation of all histones leads to decompaction, measured as an increased distance between the DNA ends, and also increased the internucleosomal distances. Selective acetylation of histone H4, however, compacts the structure as measured by FRET.
authors.affiliation: Division of Biophysics and Macromolecules, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 580, TP3, D-69120 Heidelberg, Germany.
authors.forename: Malte
authors.initials: M
authors.lastname: Bussiek
authors.forename: Katalin
authors.initials: K
authors.lastname: Tóth
authors.forename: Nathalie
authors.initials: N
authors.lastname: Schwarz
authors.forename: Jörg
authors.initials: J
authors.lastname: Langowski
mesh_terms: D000107:Acetylation; D000818:Animals; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods; D006657:Histones / Q000737:chemistry / Q000378:metabolism; D018625:Microscopy, Atomic Force / Q000379:methods; D009707:Nucleosomes / Q000737:chemistry* / Q000378:metabolism; D012492:Salts / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry; D014981:Xenopus / Q000235:genetics
chemical_list: D006657:Histones; D009707:Nucleosomes; D012492:Salts; D012965:Sodium Chloride; D004247:DNA