The Role of the Ribosome in the Accuracy of Translation

核糖体在基因型转换中起着核心作用 转化为各种生命形式的表型。由于核心核糖体功能高度 保守的，广泛的，拟议的研究的长期目标是更好地 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 已经在基因、生化和结构上研究了四年多 几十年因此，尽管已经解决了初步的X射线晶体结构， 细菌核糖体的结构， 的大肠大肠杆菌核糖体将为我们理解 蛋白质合成 核糖体通过特异性的起始、延伸和终止而起作用 步在延伸过程中，核糖体必须读取信使中的遗传密码， RNA（mRNA）的每一个连续的氨基酸，需要添加到生长 多肽链，这一过程称为解码。mRNA的核糖体解码将 通过结构和生物化学方法来探测。具体目标是： 1)提高E.大肠杆菌核糖体晶体 在我的实验室里通过形成一个模拟解码的核糖体复合物获得的， 2)以解决解码复合物中核糖体的结构，以及3）作为一种 解码缺陷的模型，以检查终止密码子的机制 通读或无义抑制，由tRNA突变引起。 这些实验将推进我们对遗传信息是如何 转化为细胞的工作部分。他们将提供一个结构性的 和生物化学的基础来模拟核糖体的分子基础 在蛋白质合成中的作用。这些研究的见解也将导致一个 更清楚地了解蛋白质合成中被许多类抑制的步骤 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.