A high-resolution map of nucleosome positioning on a fission yeast centromere.
A key element for defining the centromere identity is the incorporation of a specific histone H3, CENPA, known as Cnp1p in Schizosaccharomyces pombe. Previous studies have suggested that functional S. pombe centromeres lack regularly positioned nucleosomes and may involve chromatin remodeling as a key step of kinetochore assembly. We used tiling microarrays to show that nucleosomes are, in fact, positioned in regular intervals in the core of centromere 2, providing the first high-resolution map of regional centromere chromatin. Nucleosome locations are not disrupted by mutations in kinetochore protein genes cnp1, mis18, mis12, nuf2, mal2; overexpression of cnp1; or the deletion of ams2, which encodes a GATA-like factor participating in CENPA incorporation. Bioinformatics analysis of the centromere sequence indicates certain enriched motifs in linker regions between nucleosomes and reveals a sequence bias in nucleosome positioning. In addition, sequence analysis of nucleosome-free regions identifies novel binding sites of Ams2p. We conclude that centromeric nucleosome positions are stable and may be derived from the underlying DNA sequence.
Song
Jun S
JS
Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Liu
Xingkun
X
Liu
X Shirley
XS
He
Xiangwei
X
D002503:Centromere / Q000235:genetics*; D002874:Chromosome Mapping; D015825:Chromosomes, Fungal / Q000235:genetics*; D004271:DNA, Fungal / Q000032:analysis / Q000235:genetics; D009707:Nucleosomes / Q000235:genetics*; D012568:Schizosaccharomyces / Q000235:genetics*
D004271:DNA, Fungal; D009707:Nucleosomes