The Role of the Ribosome in the Accuracy of Translation

核糖体在基因转换中起着核心作用。 转化为所有生命形式的表型。由于核心核糖体功能高度 保守地说，拟议研究的广泛、长期目标是更好地 最简单地了解核糖体的结构和功能 自由生活的有机体，细菌。来自大肠杆菌的核糖体 已经从遗传、生化和结构上进行了四年多的研究 几十年。因此，尽管初步的x射线晶体结构已经被解决 细菌核糖体的特征不佳的嗜热菌结构 对大肠杆菌核糖体的研究将为我们理解 蛋白质合成。 核糖体通过特定的起始、延长和终止来工作。 台阶。在伸长过程中，核糖体必须读取信使中的遗传密码 需要添加到生长中的每一种连续氨基酸的RNA(MRNA) 多肽链，一个称为解码的过程。核糖体对mRNA的解码将 通过结构和生物化学方法进行探测。具体目标是： 1)提高大肠杆菌核糖体晶体的衍射分辨率 在我的实验室通过形成模拟解码的核糖体复合体获得的， 2)解决解码复合体中的核糖体结构；3)作为 破译缺陷的模型，以研究终止密码子的机制 通读，或无意义抑制，由tRNA突变引起。 这些实验将促进我们对遗传信息是如何 转化成电池的工作部件。他们将提供一个结构性的 和模拟核糖体分子基础的生化基础 在蛋白质合成中的作用。来自这些研究的见解也将导致 更清楚地了解蛋白质合成中被许多类别抑制的步骤 抗生素。

The ribosome plays a central role in the conversion of genotype into phenotype in all forms of life. Since core ribosomal functions are highly conserved, the broad, long-term objective of the proposed research is to better understand the structure and function of the ribosome in the simplest free-living organisms, bacteria. Ribosomes from the bacterium Escherichia coli have been studied genetically, biochemically, and structurally for over four decades. Thus, although preliminary x-ray crystal structures have been solved of the bacterial ribosome from a poorly characterized thermophile, structures of the E. coli ribosome will bring significant advances to our understanding of protein synthesis. The ribosome works by means of specific initiation, elongation, and termination steps. During elongation, the ribosome must read the genetic code in messenger RNA (mRNA) for each successive amino acid that needs to be added to the growing polypeptide chain, a process termed decoding. Ribosomal decoding of mRNA will be probed by both structural and biochemical approaches. The specific aims are: 1) to improve the resolution of diffraction from E. coli ribosome crystals obtained in my laboratory by forming a ribosome complex that mimics decoding, 2) to solve the structure of the ribosome in the decoding complex, and 3) as a model for decoding defects, to examine the mechanism of stop codon read-through, or nonsense suppression, caused by mutations in tRNA. These experiments will advance our knowledge of how genetic information is converted into the working parts of the cell. They will provide a structural and biochemical foundation for modeling the molecular basis for ribosome function in protein synthesis. Insights from these studies will also lead to a clearer view of steps in protein synthesis that are inhibited by many classes of antibiotics.