Skiniotis Georgios, Moazed Danesh, Walz Thomas
Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
J Biol Chem. 2007 Jul 20;282(29):20804-8. doi: 10.1074/jbc.C700081200. Epub 2007 May 29.
Post-translational acetylation of histone tails is often required for the recruitment of ATP-dependent chromatin remodelers, which in turn mobilize nucleosomes on the chromatin fiber. Here we show that the lower lobe of the ATP-dependent chromatin remodeler RSC exists in a dynamic equilibrium and can be found extended away or retracted against the tripartite upper lobe of the complex. Extension of the lower lobe increases the size of a central cavity that has been proposed to be the nucleosome binding site. We show that the presence of acetylated histone 3 N-terminal tail peptides stabilizes the lower lobe of RSC in the retracted state, suggesting that domains recognizing the acetylated histone tails reside at the interface between the two lobes. Based on three-dimensional reconstructions, we propose a model for the interaction of RSC with acetylated nucleosomes.
组蛋白尾巴的翻译后乙酰化通常是招募依赖ATP的染色质重塑因子所必需的，而这些重塑因子反过来又会在染色质纤维上移动核小体。我们在此表明，依赖ATP的染色质重塑因子RSC的下叶处于动态平衡状态，并且可以发现它远离复合体的三方上叶伸展或向其缩回。下叶的伸展增加了一个中央腔的大小，该中央腔被认为是核小体结合位点。我们表明，乙酰化组蛋白3 N端尾肽的存在使RSC的下叶稳定在缩回状态，这表明识别乙酰化组蛋白尾巴的结构域位于两个叶之间的界面处。基于三维重建，我们提出了一个RSC与乙酰化核小体相互作用的模型。
