NUCLEIC ACID STRUCTURE AND REACTIVITY

该项目的长期目标是促进 理解（1）结构化RNA分子如何催化 在没有蛋白质的情况下的生化反应，以及（2）RNA如何 与蛋白质一起参与催化作用。 在第一个宽区域中，晶体结构的域的晶体结构， 四膜虫组I核酶将用于设计和解释 RNA三级结构形成的生物化学研究。 结构性 从步骤1转换到步骤2所涉及的构象变化的基础 将研究RNA自剪接的步骤2。最后，结构 并分析肽基转移酶核酶的作用机理。 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mRNA参与了 疾病需要特定的RNA结构。 第二个广泛的领域涉及端粒酶，RNA蛋白（RNP）酶 在不同的真核生物中染色体末端复制所必需的。 研究 端粒酶的结构和组装在酿酒酵母和 粟酒裂殖酵母将整合遗传和生化 接近。 一个主要的焦点是端粒酶逆转录酶（TRT） 亚基（S.酿酒酵母作为越来越短的端粒2），牵连 作为端粒酶的催化亚单位，在许多生物体中， 人类 从纯化的端粒酶RNP中重建活性端粒酶RNP 重组成分和理解端粒酶与 其端粒底物主要以DNA-蛋白质复合物形式存在 目标. 因为端粒酶在大多数人体细胞中是无活性的， 在大多数肿瘤中重新激活，这种酶的分析可能有助于 抗端粒酶化疗药物的开发。

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.