Georgel P T, Tsukiyama T, Wu C
Laboratory of Molecular Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4255, USA.
EMBO J. 1997 Aug 1;16(15):4717-26. doi: 10.1093/emboj/16.15.4717.
The Drosophila nucleosome remodeling factor NURF utilizes the energy of ATP hydrolysis to perturb the structure of nucleosomes and facilitate binding of transcription factors. The ATPase activity of purified NURF is stimulated significantly more by nucleosomes than by naked DNA or histones alone, suggesting that NURF is able to recognize specific features of the nucleosome. Here, we show that the interaction between NURF and nucleosomes is impaired by proteolytic removal of the N-terminal histone tails and by chemical cross-linking of nucleosomal histones. The ATPase activity of NURF is also competitively inhibited by each of the four Drosophila histone tails expressed as GST fusion proteins. A similar inhibition is observed for a histone H4 tail substituted with glutamine at four conserved, acetylatable lysines. These findings indicate a novel role for the flexible histone tails in chromatin remodeling by NURF, and this role may, in part, be independent of histone acetylation.
果蝇核小体重塑因子NURF利用ATP水解的能量来扰乱核小体的结构，并促进转录因子的结合。纯化的NURF的ATP酶活性受到核小体的刺激明显大于单独的裸DNA或组蛋白，这表明NURF能够识别核小体的特定特征。在这里，我们表明，通过蛋白水解去除N端组蛋白尾巴以及通过核小体组蛋白的化学交联，NURF与核小体之间的相互作用会受到损害。NURF的ATP酶活性也受到作为GST融合蛋白表达的四种果蝇组蛋白尾巴中每一种的竞争性抑制。对于在四个保守的、可乙酰化的赖氨酸处被谷氨酰胺取代的组蛋白H4尾巴，也观察到类似的抑制作用。这些发现表明了灵活的组蛋白尾巴在NURF介导的染色质重塑中的新作用，并且这种作用可能部分独立于组蛋白乙酰化。
