Archaeal Transcription Termination

描述（由申请人提供）： 微囊膜转录与真核细胞Pol II转录具有密切的同源性，但涉及的分子组分要少得多。因此，微胶囊转录系统提供了更简单的模型方法来探测Pol II转录的机制，并研究通常与遗传疾病和癌症相关的异常转录。广古菌还含有古菌组蛋白，其将其DMA包装成古菌核小体，其具有与真核核小体中心的（H3/H4）2组蛋白四聚体相同的基本结构、DMA包装和压实性质。因此，微胶囊转录系统也可以直接解决由组蛋白和染色质施加的调节。迄今为止，只有古细菌转录起始已被详细研究。关于古细菌转录延伸知之甚少，并且古细菌转录终止尚未在体外建立。提出的实验将建立一个古细菌在体外转录系统，表现出转录终止，并将确定的分子信号/蛋白质，直接终止在古细菌。我还将确定古细菌RNA聚合酶如何通过古细菌核小体模板转录，并确定核小体的命运。

DESCRIPTION (provided by applicant): Archaeal transcription shares close homology with eukaryotic Pol II transcription but involves many fewer molecular components. Archaeal transcription systems therefore offer much simpler model approaches to probing the mechanics of Pol II transcription and investigating the aberrant transcription often associated with genetic diseases and cancers. Euryarchaea also contain archaeal histones that package their DMA into archaeal nucleosomes which have the same basic structure, DMA wrapping and compaction properties as the (H3/H4)2 histone tetramer at the center of the eukaryotic nucleosome. Archaeal transcription systems can therefore also directly address regulation imposed by histones and chromatin. To date, only archaeal transcription initiation has been studied in detail. Very little is known about archaeal transcription elongation, and archaeal transcription termination has not been established in vitro. The experiments proposed will establish an archaeal in vitro transcription system that exhibits transcription termination, and will identify the molecular signals/proteins that direct termination in Archaea. I will also determine how an archaeal RNA polymerase transcribes through an archaeal nucleosome template and determine the fate of the nucleosome.