کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2187072 | 1096096 | 2008 | 10 صفحه PDF | دانلود رایگان |
The mechanism by which chromatin is decondensed to permit access to DNA is largely unknown. Here, using a model nucleosome array reconstituted from recombinant histone octamers, we have defined the relative contribution of the individual histone octamer N-terminal tails as well as the effect of a targeted histone tail acetylation on the compaction state of the 30 nm chromatin fiber. This study goes beyond previous studies as it is based on a nucleosome array that is very long (61 nucleosomes) and contains a stoichiometric concentration of bound linker histone, which is essential for the formation of the 30 nm chromatin fiber. We find that compaction is regulated in two steps: Introduction of H4 acetylated to 30% on K16 inhibits compaction to a greater degree than deletion of the H4 N-terminal tail. Further decompaction is achieved by removal of the linker histone.
Journal: Journal of Molecular Biology - Volume 381, Issue 4, 12 September 2008, Pages 816–825