1. The octamer is the major form of CENP-A nucleosomes at human centromeres
- Author
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Ben E. Black, Nikolina Sekulic, Tanya Panchenko, Peter E. Warburton, Alicia Alonso, Kevan J. Salimian, Mishah Uzziel Salman, and Dan Hasson
- Subjects
Models, Molecular ,Chromosomal Proteins, Non-Histone ,Centromere ,macromolecular substances ,Autoantigens ,Models, Biological ,Article ,03 medical and health sciences ,Histone H3 ,0302 clinical medicine ,Structural Biology ,Centromere Protein A ,Histone methylation ,Humans ,Nucleosome ,Histone octamer ,Molecular Biology ,030304 developmental biology ,Genetics ,0303 health sciences ,biology ,Gene Expression Profiling ,Chromosome ,Nucleosomes ,Histone ,biology.protein ,Protein Multimerization ,030217 neurology & neurosurgery - Abstract
The centromere is the chromosomal locus that ensures fidelity in genome transmission at cell division. Centromere protein A (CENP-A) is a histone H3 variant that specifies centromere location independently of DNA sequence. Conflicting evidence has emerged regarding the histone composition and stoichiometry of CENP-A nucleosomes. Here we show that the predominant form of the CENP-A particle at human centromeres is an octameric nucleosome. CENP-A nucleosomes are very highly phased on α-satellite 171-base-pair monomers at normal centromeres and also display strong positioning at neocentromeres. At either type of functional centromere, CENP-A nucleosomes exhibit similar DNA-wrapping behavior, as do octameric CENP-A nucleosomes reconstituted with recombinant components, having looser DNA termini than those on conventional nucleosomes containing canonical histone H3. Thus, the fundamental unit of the chromatin that epigenetically specifies centromere location in mammals is an octameric nucleosome with loose termini.
- Published
- 2013
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