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Citation
Dalal, Y., Wang, H., Lindsay, S., Henikoff, S. (2007). Tetrameric structure of centromeric nucleosomes in interphase Drosophila cells.  PLoS Biol. 5(8): e218.
FlyBase ID
FBrf0201058
Publication Type
Research paper
Abstract

Centromeres, the specialized chromatin structures that are responsible for equal segregation of chromosomes at mitosis, are epigenetically maintained by a centromere-specific histone H3 variant (CenH3). However, the mechanistic basis for centromere maintenance is unknown. We investigated biochemical properties of CenH3 nucleosomes from Drosophila melanogaster cells. Cross-linking of CenH3 nucleosomes identifies heterotypic tetramers containing one copy of CenH3, H2A, H2B, and H4 each. Interphase CenH3 particles display a stable association of approximately 120 DNA base pairs. Purified centromeric nucleosomal arrays have typical "beads-on-a-string" appearance by electron microscopy but appear to resist condensation under physiological conditions. Atomic force microscopy reveals that native CenH3-containing nucleosomes are only half as high as canonical octameric nucleosomes are, confirming that the tetrameric structure detected by cross-linking comprises the entire interphase nucleosome particle. This demonstration of stable half-nucleosomes in vivo provides a possible basis for the instability of centromeric nucleosomes that are deposited in euchromatic regions, which might help maintain centromere identity.

PubMed ID
PubMed Central ID
PMC1933458 (PMC) (EuropePMC)
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Secondary IDs
    Language of Publication
    English
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Journal
    Abbreviation
    PLoS Biol.
    Title
    PLoS Biology
    Publication Year
    2003-
    ISBN/ISSN
    1545-7885 1544-9173
    Data From Reference
    Genes (5)
    Physical Interactions (4)
    Cell Lines (1)