Histones and Nucleosomes in Archaea

古细菌中的组蛋白和核小体

• 批准号: 7071826
• 负责人: JOHN NEWTON REEVE
• 金额: $ 27.45万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7071826
• 关键词: Archaea; DNA binding protein; Escherichia coli; X ray crystallography; biochemical evolution; chromatin immunoprecipitation; circular DNA; crystallization; dimer; gene expression; genome; histones; intermolecular interaction; microarray technology; microorganism genetics; molecular assembly /self assembly; nucleic acid sequence; nucleosomes; polymerase chain reaction; protein folding; protein localization; protein structure function; recombinant proteins; species difference

DESCRIPTION (provided by applicant): Archaeal histones share a common ancestry with the histone-folds of the eukaryotic nucleosome cores histones and subunits of many large eukaryotic transcription factors. The histone fold is a structural motif that directs dimer formation, and archaeal histones form homodimers and heterodimers but eukaryotic histone folds now form only heterodimers. Archaeal histones also bind DNA and assemble into complexes spontaneously and individually, and can wrap DNA in either a negative or positive supercoil. They therefore provide a unique opportunity, and a practical experimental system to establish the molecular determinants of histone:histone and histone:DNA interactions. The experiments proposed will generate a detailed structural understanding of histone fold partner specificity, histone-DNA affinity, the positioning of histone assembly, and the determinants of the direction of DNA supercoiling. These are all issues of central and fundamental importance to understanding genome organization and the roles of histones and histone foldcontaining complexes in regulating gene expression in Eukaryotes, and in Archaea. The information gained will also be of importance in understanding how defects in these molecular assemblies and interactions negatively impact human development and health. We have established that different archaeal histone assemblies have sequence-dependent differences in DNA affinity, and this suggests an entirely novel concept for gene regulation based on alternative histone dimer assembly. Chromatin immunoprecipitation coupled with DNA microarray hybridization will be used to investigate this new idea, and to test the hypothesis that this archaeal histone regulatory system was the foundation for eukaryotic genome silencing and gene regulation by positioned nucleosome assembly.

描述（由申请人提供）：古细胞蛋白与真核核小体核心组的组蛋白共享共同的血统和许多大型真核转录因子的亚基。组蛋白折叠是一种指导二聚体形成的结构基序，古细胞组蛋白形成同二聚体和异二聚体，但真核组织组蛋白折叠现在仅形成异二聚体。古细胞蛋白还可以自发和单独地结合DNA并组装成复合物，并可以将DNA包裹在负或阳性超副盘中。因此，它们提供了一个独特的机会，也提供了实用的实验系统来建立组蛋白的分子决定因素：组蛋白和组蛋白：DNA相互作用。提出的实验将对组蛋白折叠伴侣特异性，组蛋白DNA亲和力，组蛋白组装的定位以及DNA超螺旋方向的决定因素产生详细的结构理解。这些都是对理解基因组组织以及组蛋白和组蛋白折叠复合物在调节真核生物和古细菌中基因表达中的作用的中心和根本重要性的问题。获得的信息也将在理解这些分子组件中的缺陷以及相互作用对人类发展和健康的负面影响。我们已经确定，不同的古细胞蛋白组件在DNA亲和力上具有序列依赖性差异，这表明基于替代组蛋白二聚体组装的基因调节的一个完全新颖的概念。结合DNA微阵列杂交的染色质免疫沉淀将用于研究这一新想法，并检验以下假设：这种古细胞组蛋白调节系统是通过定位的核小组组装的真核基因组沉默和基因调节的基础。