Amati B, Pick L, Laroche T, Gasser S M
Swiss Institute for Experimental Cancer Research (ISREC), Epalinges s/Lausanne.
EMBO J. 1990 Dec;9(12):4007-16. doi: 10.1002/j.1460-2075.1990.tb07622.x.
Nuclei isolated from eukaryotic cells can be depleted of histones and most soluble nuclear proteins to isolate a structural framework called the nuclear scaffold. This structure maintains specific interactions with genomic DNA at sites known as scaffold attached regions (SARs), which are thought to be the bases of DNA loops. In both Saccharomyces cerevisiae and Schizosaccharomyces pombe, genomic ARS elements are recovered as SARs. In addition, SARs from Drosophila melanogaster bind to yeast nuclear scaffolds in vitro and a subclass of these promotes autonomous replication of plasmids in yeast. In the present report, we present fine mapping studies of the Drosophila ftz SAR, which has both SAR and ARS activities in yeast. The data establish a close relationship between the sequences involved in ARS activity and scaffold binding: ARS elements that can bind the nuclear scaffold in vitro promote more efficient plasmid replication in vivo, but scaffold association is not a strict prerequisite for ARS function. Efficient interaction with nuclear scaffolds from both yeast and Drosophila requires a minimal length of SAR DNA that contains reiteration of a narrow minor groove structure of the double helix.
从真核细胞中分离出的细胞核可以去除组蛋白和大多数可溶性核蛋白，以分离出一种称为核支架的结构框架。这种结构在称为支架附着区域（SAR）的位点与基因组DNA保持特定相互作用，这些位点被认为是DNA环的基础。在酿酒酵母和粟酒裂殖酵母中，基因组ARS元件都作为SAR被回收。此外，果蝇的SAR在体外与酵母核支架结合，其中一个亚类可促进酵母中质粒的自主复制。在本报告中，我们展示了对果蝇ftz SAR的精细定位研究，该SAR在酵母中具有SAR和ARS活性。数据表明了参与ARS活性的序列与支架结合之间的密切关系：在体外能够结合核支架的ARS元件在体内可促进更有效的质粒复制，但支架结合并非ARS功能的严格先决条件。与酵母和果蝇的核支架进行有效相互作用需要最小长度的SAR DNA，该DNA包含双螺旋窄小沟结构的重复序列。
