Blank T A, Sandaltzopoulos R, Becker P B
European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
Methods. 1997 May;12(1):28-35. doi: 10.1006/meth.1997.0444.
The biochemical analysis of chromatin structure and function is greatly facilitated by the availability of cell-free systems that assemble chromatin under physiological conditions. One such system that has shown great potential is derived from extracts of early Drosophila embryos. These embryos contain large maternal stocks of chromatin constituents, such as histones and assembly factors. Chromatin assembled in these extracts resembles native chromatin in many respects: it displays physiological nucleosome repeat lengths, it is complex, containing a wealth of nonhistone proteins as well as enzymatic activities, and it has dynamic properties that allow the interaction of DNA-binding proteins that regulate important cellular processes. Most importantly, chromatin with variant properties, e.g., with respect to the basic geometry of the nucleosomal array, histone modifications, and its content of linker histones or nonhistone proteins, can be obtained by manipulating the reconstitution conditions. The synthesis of uniform chromatin with specific characteristics should allow the analysis of the functional significance of the structural and biochemical heterogeneity observed in vivo.
无细胞体系能够在生理条件下组装染色质，这极大地促进了对染色质结构和功能的生化分析。一种显示出巨大潜力的此类体系源自果蝇早期胚胎提取物。这些胚胎含有大量染色质成分的母体储备，如组蛋白和组装因子。在这些提取物中组装的染色质在许多方面类似于天然染色质：它显示出生理核小体重复长度，它很复杂，包含大量非组蛋白以及酶活性，并且它具有动态特性，允许调节重要细胞过程的DNA结合蛋白相互作用。最重要的是，通过操纵重构条件，可以获得具有变体特性的染色质，例如关于核小体阵列的基本几何形状、组蛋白修饰及其连接组蛋白或非组蛋白的含量。合成具有特定特征的均匀染色质应有助于分析体内观察到的结构和生化异质性的功能意义。
