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XB-ART-54037
PLoS One January 1, 2016; 11 (11): e0165078.

CENP-A and H3 Nucleosomes Display a Similar Stability to Force-Mediated Disassembly.

Kim SH , Vlijm R , van der Torre J , Dalal Y , Dekker C .


Abstract
Centromere-specific nucleosomes are a central feature of the kinetochore complex during mitosis, in which microtubules exert pulling and pushing forces upon the centromere. CENP-A nucleosomes have been assumed to be structurally unique, thereby providing resilience under tension relative to their H3 canonical counterparts. Here, we directly test this hypothesis by subjecting CENP-A and H3 octameric nucleosomes, assembled on random or on centromeric DNA sequences, to varying amounts of applied force by using single-molecule magnetic tweezers. We monitor individual disassembly events of CENP-A and H3 nucleosomes. Regardless of the DNA sequence, the force-mediated disassembly experiments for CENP-A and H3 nucleosomes demonstrate similar rupture forces, life time residency and disassembly steps. From these experiments, we conclude that CENP-A does not, by itself, contribute unique structural features to the nucleosome that lead to a significant resistance against force-mediated disruption. The data present insights into the mechanistic basis for how CENP-A nucleosomes might contribute to the structural foundation of the centromere in vivo.

PubMed ID: 27820823
PMC ID: PMC5098787
Article link: PLoS One

Genes referenced: cenpa tab3


Article Images: [+] show captions
References [+] :
Andrews, The histone chaperone Nap1 promotes nucleosome assembly by eliminating nonnucleosomal histone DNA interactions. 2010, Pubmed, Xenbase


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