X RAY CRYSTALLOGRAPHY OF ANTIBIOTICS BOUND TO RIBOSOMES

这个项目的长期目标是通过在原子分辨率下解决核糖体亚单位(或整个核糖体)的结构来提高对蛋白质翻译的理解。该项目更直接的目标是通过结晶学深入了解核糖体-抗生素的相互作用。具体地说，各种抗体和抑制剂将被渗透到核糖体晶体中或与核糖体共结晶，并在不同的傅立叶电子密度图中确定结合位置。一个将被研究的关键抑制剂是多肽转移反应的即时类似物(CcdApPuro)。目前的研究主要集中在大洋盐藻核糖体大亚基的晶体上，这些晶体的相信息可以在GA分辨率下获得。在这种分辨率下，结合的抗生素很可能在不同的傅立叶电子密度图中被看到。这些抗生素在6A分辨率下的位置及其结合位点的结构信息将为蛋白质翻译和抗生素对翻译的抑制提供新的见解。此外，随着相信息的质量和分辨率有望提高，相应地，抗生素实验获得的信息的质量也有望提高。此外，当构建核糖体原子模型的任务开始时，这些抗生素结合部位的位置知识可能会很有用。

DESCRIPTION The long term goal of this project is to advance the understanding of protein translation by solving the structures of ribosomal subunits (or of entire ribosomes) at atomic resolution. The more immediate goal of this project is to gain insight into ribosome-antibiotic interactions through crystallography. Specifically, various antibodies and inhibitors will be soaked into ribosomal crystals or co-crystalized with ribosomes, and the binding sites identified in difference Fourier electron density maps. One key inhibitor that will be studied is an analogue of the immediate of the peptidyl transfer reaction (CcdApPuro). Current research focuses on crystals of the large ribosomal subunit of Haloarcula marismortui for which phase information is available at G A resolution. At this resolution bound antibiotics are likely to be seen in difference Fourier electron density maps. Location of these antibiotics and structural information about their binding sites at 6 A resolution would provide new insight into protein translation and into antibiotic inhibition of translation. In addition, as the quality and resolution of the phase information is expected to improve, correspondingly, the quality of information gained from the antibiotic experiments is expected to improve. In addition, knowledge of the location of these antibiotic binding sites is likely to be useful when the task of building an atomic model of ribosomes begins.