Abstract
The distinct contributions of histone tails and their acetylation to nucleosomal stability were examined by mechanical disruption of individual nucleosomes in a single chromatin fiber using an optical trap. Enzymatic removal of H2A/H2B tails primarily decreased the strength of histone-DNA interactions located ∼±36 bp from the dyad axis of symmetry (off-dyad strong interactions), whereas removal of the H3/H4 tails played a greater role in regulating the total amount of DNA bound. Similarly, nucleosomes composed of histones acetylated to different degrees by the histone acetyltransferase p300 exhibited significant decreases in the off-dyad strong interactions and the total amount of DNA bound. Acetylation of H2A/H2B appears to play a particularly critical role in weakening the off-dyad strong interactions. Collectively, our results suggest that the destabilizing effects of tail acetylation may be due to elimination of specific key interactions in the nucleosome.
Original language | English (US) |
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Pages (from-to) | 135-146 |
Number of pages | 12 |
Journal | Journal of Molecular Biology |
Volume | 346 |
Issue number | 1 |
DOIs | |
State | Published - Feb 11 2005 |
Keywords
- acetyation
- histone tails
- nucleosome
- optical trapping
- single molecule
ASJC Scopus subject areas
- Structural Biology
- Molecular Biology