A high-resolution map of nucleosome positioning on a fission yeast centromere
Abstract
A key element for defining the centromere identity is the incorporation of a specific histone H3, CENP-A, known as Cnp1p in S. 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 CENP-A incorporation. Bioinformatic 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.
Footnotes
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- Received December 7, 2007.
- Accepted April 3, 2008.
- Copyright © 2008, Cold Spring Harbor Laboratory Press
