title: Chromatin folding modulates nucleosome positioning in yeast minichromosomes.
abstract: Based on the chromatin structures of the yeast URA3 gene and the TRP1ARS1 circle, we have designed circular minichromosomes of different sizes that should each form a tight tetranucleosome. This structure was assumed to be stiff and bulky and therefore likely to be sensitive to packaging into a three-dimensional structure. The structures of the minichromosomes were determined using micrococcal nuclease. Only one of the minichromosomes showed a protected region of about 570 bp, compatible with the predicted tight tetranucleosome, while all other constructs showed alternative structures. A comparison of the structures revealed that neither histone-DNA interactions nor influences from flanking boundaries are sufficient determinants of nucleosome positions. The data strongly suggest that chromatin folding modulates the nucleosome arrangement along the DNA.
authors.affiliation: Institut für Zellbiologie, ETH-Hönggerberg, Zürich, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Thoma
authors.forename: M
authors.initials: M
authors.lastname: Zatchej
mesh_terms: D002843:Chromatin / Q000648:ultrastructure*; D004261:DNA Replication; D004271:DNA, Fungal / Q000648:ultrastructure; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000648:ultrastructure*; D012441:Saccharomyces cerevisiae / Q000235:genetics*
chemical_list: D002843:Chromatin; D004271:DNA, Fungal; D009707:Nucleosomes