NUCLEIC ACID STRUCTURE-FUNCTION IN GENE EXPRESSION

本申请中提出的研究是我们的 一般的努力，以确定如何具体的特点，核酸 顺序和结构是步骤中的控制点， 的基因表达。 重点是合成，加工， 和信使RNA的功能。 一组自然重叠的 多顺反子mRNAs编码蛋白质， 不同的产量将被调查，以确定什么作用， 这些mRNA转录物的转录后加工事件 在翻译过程中进行，以及随后的控制， 影响差异基因表达。 宿主核酸酶活性 负责处理mRNA的是 特征，以了解更多关于酶，使特定 在mRNA中的切割以及这些酶在 牢房 宿主突变体不能进行这些处理 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。 经由 核苷酸序列系统处理和直接研究 RNA结构、mRNA的功能元件 加工位点和引发活动的决定因素 将鉴定选定的翻译起始区。 通过 直接检查体内转录过程， 序列特异性DNA结合蛋白的研究进展 将检测延伸RNA聚合酶。 总的来说， 实验系统的生物学特性，及其 适用于体外生物化学分析和 体内功能研究，确保大量的贡献， 这项工作有助于更好地理解这些重要步骤 的基因表达。

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.