Molecular Role of 16S Ribosomal RNA in Translocation

描述（由申请人提供）：蛋白质合成是一个基本过程 在所有生物体中。核糖体是核糖核蛋白复合体 负责蛋白质合成。最近的原子分辨率结构的 大小核糖体亚基提供了一个独特的机会， 核糖体完成蛋白质合成这一复杂任务的机制。 蛋白质合成延长周期中的重要步骤之一是 tRNA-mRNA复合物的反复移动，这一过程称为易位。在 大肠杆菌，延伸因子G（EF-G）催化易位。的 EF-G依赖性易位的机制知之甚少。长期 我实验室的目标是阐明易位的分子基础。 几项研究表明，核糖体RNA（rRNA）可能发挥着重要作用， 在易位过程中的作用。我们最近开发了一种小说 修改干预的方法，这将使我们能够检查的作用， 16 S rRNA易位。该方法使用高效的特定于站点的 P位点结合的tRNA和16 S rRNA之间的交联，以选择 在易位中活跃。我们将使用一种组合方法来识别 碱基、非桥接磷酸氧和16 S内的核糖2 '-羟基 rRNA对于易位至关重要。这项研究将提供信息 关于核糖体结构的动力学， X射线晶体学 核糖体是几类抗生素灭活的靶点。 抗生素如红霉素、壮观霉素、紫霉素、硫链丝菌素，和 氨基糖苷类特异性抑制易位。其中一些 抗生素阻止16 S rRNA发生结构变化， 对于易位至关重要。抗生素耐药菌株的细菌是在 上升，导致这些感染的管理和治疗危机 在全世界都有。了解易位的机制将提供 开发更有效的抗生素的见解，靶向核糖体 这些耐药菌株。

DESCRIPTION (provided by applicant): Protein synthesis is a fundamental process in all living organisms. Ribosomes are the ribonucleoprotein complexes responsible for protein synthesis. Recent atomic resolution structures of the large and small ribosomal subunits provide a unique opportunity to understand the mechanism by which ribosomes perform the complex task of protein synthesis. One of the important steps in the elongation cycle of protein synthesis is the iterative movement of the tRNA-mRNA complex, a process called translocation. In Escherichia coli, elongation factor G (EF-G) catalyzes translocation. The mechanism of EF-G-dependent translocation is poorly understood. The long-term goal of my laboratory is to elucidate the molecular basis of translocation. Several lines of studies indicate that the ribosomal RNAs (rRNAs) may play a functional role during translocation. We recently developed a novel modification-interference approach that will permit us to examine the role of 16S rRNA in translocation. The method uses a highly efficient site-specific cross-link between P site bound tRNA and 16S rRNA to select ribosomes that are active in translocation. We will use a combinatorial approach for identifying bases, non-bridging phosphate oxygens, and ribose 2'-hydroxyl groups within 16S rRNA that are critical for translocation. This study will provide information about the dynamics of ribosome structure that cannot be easily acquired by X-ray crystallography. Ribosomes are the target for inactivation by several classes of antibiotics. Antibiotics such as eiythromycin, spectionmycin, viomycin, thiostrepton, and the aminoglycosides specifically inhibit translocation. Some of these antibiotics prevent the 16S rRNA from undergoing structural changes that are critical for translocation. Antibiotic-resistant strains of bacteria are on the rise, causing a crisis in the management and treatment of these infections throughout the world. Understanding the mechanism of translocation will provide insights for developing more effective antibiotics that target the ribosome of these drug-resistant strains of bacteria.