Centromeric Nucleosomes Induce Positive DNA Supercoils

摘要: Centromeres of higher eukaryotes are epigenetically maintained; however, the mechanism that underlies centromere inheritance is unknown. Centromere identity and require assembly nucleosomes containing CenH3 histone variant in place canonical H3. Although H3 wrap DNA a left-handed manner induce negative supercoils, we show here reconstituted from Drosophila histones positive supercoils. Furthermore, likewise induces supercoils functional centromeres vivo, using budding yeast minichromosome system temperature-sensitive mutations kinetochore proteins. The right-handed wrapping around core implied by supercoiling indicates unlikely to be octameric exposed surfaces holding nucleosome together would available for protein recruitment. mutual incompatibility with opposite topologies could explain how efficiently maintained as unique loci on chromosomes.