DNA TOPOLOGY, CHROMATIN STRUCTURE, AND TRANSCRIPTION

描述：本提案旨在确定扭转应力的作用 在染色质结构和转录中。 一组实验将 确定核小体在转录过程中是否被置换。 下一组实验将开发合成拓扑域， 一种质粒，它将被分为两个受lac限制的结构域， 阻遏物：操纵基因复合物。 合成结构域可以形成为 一个域代替两个独立的域， 不发生四聚化的突变型乳糖阻遏物。 另外的实验 将决定是否扭转应力诱导的分子， 转录足以重组染色质，或者如果染色质 重组仅通过与聚合酶直接接触发生 复杂. 转录和表达的核小体结构分析 非转录区将进行，和转录率 将在每种情况下确定。

DESCRIPTION: This proposal aims to determine the role of torsional stress in chromatin structure and transcription. One set of experiments will determine whether or not nucleosomes are displaced during transcription. The next set of experiments will develop synthetic topological domains using a plasmid that will be divided into two domains constrained by lac repressor:operator complexes. The synthetic domains can be formed into a single domain instead of two independent domains by the substitution of a mutant lac repressor which does not tetramerize. Additional experiments will determine whether torsional stress induced in the molecule by transcription is sufficient to reorganize chromatin, or if chromatin reorganization takes place only through direct contact with the polymerase complex. An analysis of nucleosome architecture in transcribed and non-transcribed regions will be carried out, and the rate of transcription will be determined in each case.