NUCLEIC ACID STRUCTURE AND REACTIVITY

该项目的长期目标是为 理解(1)结构的RNA分子如何催化 没有蛋白质时的生化反应，以及(2)RNA是如何 与蛋白质协同参与催化作用。 在第一个宽广的区域中， 四膜虫I组核酶将用于设计和解释 核糖核酸三级结构形成的生化研究。结构性的 从步骤1转换到的构象变化的基础 我们将研究RNA自剪接的第二步。最后，结构 并对肽基转移酶核酶的作用机制进行了分析。 核酶的结构-功能关系与健康有关 因为RNA病毒、逆转录病毒和细胞内的mRNAs参与 疾病需要特定的RNA结构。 第二个广泛的领域与端粒酶有关，即RNA-蛋白质(RNP)酶 在不同的真核生物中染色体末端复制所需的。研究 酿酒酵母和酿酒酵母端粒酶结构和组装的研究 庞氏裂殖酵母将整合遗传和生化 接近了。一个主要的焦点是端粒酶逆转录酶(TRT) 亚单位(在酿酒酵母中称为更短的端粒2)，牵涉到 作为端粒酶的催化亚单位，在许多生物体中，包括 人类。纯化的端粒酶活性RNP的重组 重组组分及其与端粒酶相互作用的理解 其端粒底物主要以DNA-蛋白质复合体形式存在 目标。因为端粒酶在大多数人体细胞中是不活跃的，但 在大多数肿瘤中重新激活，对这种酶的分析可能有助于 抗端粒酶化疗药物的研究进展。

The long-term goals of this project are to contribute to the understanding of (1) how structured RNA molecules can catalyze biochemical reactions in the absence of proteins, and (2) how RNA participates in catalysis in concert with proteins. In the first broad area, the crystal structure of a domain of the Tetrahymena group I ribozyme will be used to design and interpret biochemical studies of RNA tertiary structure formation. The structural basis of a conformational change involved in switching from step 1 to step 2 of RNA self-splicing will be investigated. Finally, the structure and mechanism of a peptidyl transferase ribozyme will be analyzed. Structure-function relationships in ribozymes are related to health because RNA viruses, retroviruses, and cellular mRNAs involved in disease require specific RNA structures. The second broad area concerns telomerase, the RNA-protein (RNP) enzyme required for chromosome end replication in diverse eukaryotes. Studies of telomerase structure and assembly in Saccharomyces cerevisiae and Schizosaccharomyces pombe will integrate genetic and biochemical approaches. A major focus is the Telomerase Reverse Transcriptase (TRT) subunit (known in S. cerevisiae as Ever Shorter Telomeres 2), implicated as the catalytic subunit of telomerase in many organisms including humans. Reconstitution of active telomerase RNP from purified recombinant components and understanding interactions of telomerase with its telomeric substrate present as a DNA-protein complex are major goals. Because telomerase is inactive in most human somatic cells but reactivated in most tumors, analysis of this enzyme may contribute to development of anti-telomerase chemotherapeutics.