STRUCTURAL STUDIES OF THE RIBOSOMAL PROTEIN S15

肿瘤形成和癌变的机制基础涉及基因表达的异常调节。 RNA：蛋白质相互作用对于所有水平的基因表达（例如转录、剪接和翻译）都是重要的。 作为研究RNA：蛋白质相互作用的模型系统，威廉姆森小组正在研究核糖体蛋白S15与16 S核糖体RNA结合的复合物。 S15蛋白是30 S核糖体颗粒组装所需的主要核糖体结合蛋白之一。 核糖体蛋白S15也通过与其自身信使RNA的5 '-非翻译区（5'-UTR）结合来调节其自身的表达，并因此减少S15蛋白的翻译。 该项目的总体目标是了解这种5 '-UTR mRNA：S15复合物的特异性相互作用的结构基础。从S15的5 '-UTR mRNA结合位点的生物化学表征开始，可以制备最小位点用于通过NMR光谱法的进一步研究。 在NMR结构解析中，将合成特异性同位素标记的核糖核苷酸，从而简化NMR光谱。 对这种5 '-UTR mRNA：S15复合物的研究将与实验室中已经进行的16 S rRNA：S15复合物的研究形成对比。这项研究之所以重要，有三个原因。1)我们将扩展有关RNA的一般知识：蛋白质识别。2)有关负责S15识别两个看似不同的RNA的特定相互作用和构象变化的细节将被了解。3)新的工具和策略将被开发，直接对生物学中丰富的大型多组分复合物的研究。

The mechanistic basis of neoplasia and carcinogenesis involves abnormal regulation of gene expression. RNA: protein interactions are important for all levels of gene expression (e.g. transcription, splicing, and translation). As a model system for studying RNA:protein interactions, the Williamson group is studying a complex of ribosomal protein S15 bound to 16S ribosomal RNA. The S15 protein is just one of the primary ribosomal binding proteins required for the assembly of the 30S ribosomal particle. The ribosomal protein S15 also regulates its own expression by binding to the 5'-untranslated region (5'-UTR) of its own messenger RNA and, consequently, reducing translation of S15 protein. The overall goal of this project is to understand the structural basis for the specific interactions of this 5'-UTR mRNA:S15 complex. Beginning with biochemical characterization of the 5'-UTR mRNA binding site for S15, a minimal site can be prepared for further study by NMR spectroscopy. Aiding in the NMR structure elucidation, specifically isotopically labeled ribonucleotides will be synthesized, thus simplifying the NMR spectra. The study of this 5'-UTR mRNA:S15 complex will provide contrast to studies of the 16S rRNA:S15 complex already underway in the lab. This research is significant for three reasons. 1) We will extend general knowledge about RNA:protein recognition. 2) Details about the particular interactions and conformation changes responsible for S15 recognition of two seemingly dissimilar RNAs will be learned. 3) New tools and strategies will be developed directed toward the study of large multicomponent complexes abundant in biology.