NUCLEIC ACID STRUCTURE-FUNCTION IN GENE EXPRESSION

本申请中提出的研究是我们的 确定核酸的具体特征的一般努力 序列和结构是步骤中的控制点 关于基因表达的。重点放在合成，加工， 和信使RNA的功能。一组自然的重叠 编码蛋白质的多顺反子mRNAs在 将对不同的收益率进行调查，以确定 这些mRNA转录本的转录后加工事件 在翻译过程中经历以及随后的控制，发挥作用 影响差异基因表达的。宿主核酸酶活性 负责处理mRNAs的人将是 特征，以了解更多关于使特定的 MRNA的裂解以及这类酶在 牢房。寄主不能进行这些处理的突变体 这些活动将极大地促进解决这些问题， 将对这些突变体进行遗传选择。通过 核苷酸序列的系统操作和直接研究 RNA结构中，信使核糖核酸的功能元件 加工点和引发活性的决定因素 选定的翻译启动子区域将被识别。穿过 直接检测体内转录过程，效果 序列特异性DNA结合蛋白的研究进展 将检查延长的RNA聚合酶。总体而言，独特的 实验系统的生物学特性以及它们的 体外生化分析与联合应用的适宜性 体内功能研究，确保来自 这项工作有助于更好地理解这些重要步骤 关于基因表达的。

The research proposed in this application is a continuation of our general effort to establish how specific features of nucleic acid sequence and structure serve as controlling points during the steps of gene expression. The emphasis is on the synthesis, processing, and function of messenger RNA. A natural set of overlapping polycistronic mRNAs encoding proteins expressed in strikingly disparate yields will be investigated, to determine what roles the post-transcriptional processing events these mRNA transcripts undergo, as well as subsequent controls during translation, play in effecting differential gene expression. Host nuclease activity responsible for the processing of the mRNAs will be characterized, to learn more about enzymes that make specific cleavages in mRNA and about the functions such enzymes have in the cell. Host mutants that fail to carry out these processing events will greatly facilitate addressing these problems, and genetic selections for such mutants will be carried out. Via systematic manipulation of necleotide sequence and direct study of RNA structure, the functional elements of the MRNA processing sites and the determinants of initiation activity in selected translational initiator regions will be identified. Through direct examination of the in vivo transcription process, the effect of sequence-specific DNA binding proteins on the progress of elongating RNA polymerase will be examined. Overall, the unique biological properties of the experimental systems, and their suitability for a combination of in vitro biochemical analysis and in vivo functional studies, ensure substantial contibutions from this work to an improved understanding of these important steps of gene expression.