ISOLATION AND CHARACTERIZATION OF ACANTHAMOEBA GENES

稳定RNA的转录和表达调控机制 （前体核糖体和5S）正在研究中。 监管证据 通过调节辅助转录蛋白稳定RNA合成 水平，通过RNA聚合酶修饰和反式作用蛋白质， 在这个实验室和其他实验室里得到的。 作为研究 5S RNA转录调控机制、5S RNA的克隆 基因，确定其总体基因组结构和一级序列 本文提出 5S RNA无细胞转录系统的建立 补充rRNA转录系统已经在这个实验室使用， 提出了 5S RNA转录系统将被用来检查 发育调控5S RNA关闭的分子机制 表情 重点将放在研究 5S和核糖体RNA的平行关闭机制， 细胞生长和增殖的停止。 rRNA启动子结构的研究正在进行中。 删除 在体外构建并测试转录活性的突变， 鉴定了rRNA转录起始点附近的50个碱基对区域 作为启动子。 该提案旨在提出一系列要点， 为了更精确地定义这个序列中的突变， 启动子和辅助转录蛋白之间的相互作用。

Mechanisms of transcription and regulation of expression of stable RNAs (precursor ribosomal and 5S) are being studied. Evidence for regulation of stable RNA synthesis by modulation of auxilliary transcriptional protein levels, by RNA polymerase modification and by trans-acting proteins has been obtained in this lab and others. As an initial step in studying the mechanism of regulation of 5S RNA transcription, cloning of the 5S RNA gene, determination of its overall genomic structure and primary sequence is proposed. Development of a cell-free transcription system for 5S RNA to complement the rRNA transcription system already in use in this lab is also proposed. The 5S RNA transcription system will be utilized to examine the molecular mechanism of developmentally regulated shutoff of 5S RNA expression. Emphasis will be on studying the relationship between the mechanisms of the parallel shutdown of 5S and ribosomal RNA resulting from cessation of cellular growth and proliferation. Studies of the structure of the rRNA promoter are ongoing. Deletion mutations constructed and tested for transcriptional activity in vitro have identified a 50 base pair region proximal to the rRNA transcription start site as the promoter. This proposal aims to produce a series of point mutations within this sequence in order to more precisely define the interactions between the promoter and auxilliary transcriptional proteins.