Wellcome Trust Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee, UK.
EMBO J. 2011 May 27;30(13):2596-609. doi: 10.1038/emboj.2011.166.
The ATP-dependent chromatin-remodelling enzyme Chd1 is a 168-kDa protein consisting of a double chromodomain, Snf2-related ATPase domain, and a C-terminal DNA-binding domain. Here, we show the DNA-binding domain is required for Saccharomyces cerevisiae Chd1 to bind and remodel nucleosomes. The crystal structure of this domain reveals the presence of structural homology to SANT and SLIDE domains previously identified in ISWI remodelling enzymes. The presence of these domains in ISWI and Chd1 chromatin-remodelling enzymes may provide a means of efficiently harnessing the action of the Snf2-related ATPase domain for the purpose of nucleosome spacing and provide an explanation for partial redundancy between these proteins. Site directed mutagenesis was used to identify residues important for DNA binding and generate a model describing the interaction of this domain with DNA. Through inclusion of Chd1 sequences in homology searches SLIDE domains were identified in CHD6-9 proteins. Point mutations to conserved amino acids within the human CHD7 SLIDE domain have been identified in patients with CHARGE syndrome.
ATP 依赖的染色质重塑酶 Chd1 是一种 168kDa 的蛋白质,由双 chromodomain、Snf2 相关的 ATP 酶结构域和 C 末端 DNA 结合结构域组成。在这里,我们表明 DNA 结合结构域对于酿酒酵母 Chd1 结合和重塑核小体是必需的。该结构域的晶体结构揭示了与先前在 ISWI 重塑酶中鉴定出的 SANT 和 SLIDE 结构域存在结构同源性。ISWI 和 Chd1 染色质重塑酶中的这些结构域可能提供了一种有效利用 Snf2 相关 ATP 酶结构域进行核小体间隔的方法,并为这些蛋白质之间的部分冗余提供了解释。定点突变用于鉴定对 DNA 结合重要的残基,并生成一个描述该结构域与 DNA 相互作用的模型。通过在同源性搜索中包含 Chd1 序列,在 CHD6-9 蛋白中鉴定出 SLIDE 结构域。CHARGE 综合征患者中已鉴定出人类 CHD7 SLIDE 结构域中保守氨基酸的点突变。