Structural and biophysical studies of proteins, nucleic acids, and their complexes

 描述(申请人提供)：本提案的中心主题是核酸、蛋白质及其相互作用的结构和机制研究。我们的研究重点有两个：1)拓扑异构酶的结构和机制；2)RNaseP的结构、体系和机制。我们的工作目的是发现和探索有助于阐明生命三个领域(细菌、古生物和真核生物)共同的生物分子的结构和机制的范式。拓扑异构酶是一种普遍存在的蛋白质，存在于生命的所有三个领域。它们参与了几个细胞过程，它们是几种癌症化疗药物和抗生素的靶标，这一事实突显了它们在细胞中作用的重要性。对拓扑异构酶的结构、机制和功能的研究不仅有助于我们在许多不同水平上理解与dna相互作用并改变其拓扑结构的蛋白质。 但也提供了重要的信息，以帮助设计新的治疗剂。为了实现我们的目标，我们对拓扑异构酶的全面研究将集中在两个大型和互补的项目上：项目1.IA型、IC和II型拓扑异构酶的结构和生化研究，以及项目2.IA型和II型拓扑异构酶的单分子研究。这两个重大项目将有助于回答将该领域推向下一阶段所需的关键问题。核糖核酸酶P是一种核糖核蛋白复合体，存在于从细菌到人类的几乎所有生物体中，负责处理细胞中许多不同的RNA分子。它由一个基本的RNA亚基和一个或多个蛋白质组成，但在所有情况下，RNA成分都负责催化作用。RNaseP是最早发现的催化RNA分子之一，它的研究对于我们理解RNA分子在催化中的作用是至关重要的。我们对RNaseP结构和功能的研究为细胞内RNA加工中的一种关键核酶提供了重要的相关信息，同时也加深了我们对大RNA分子和核糖核蛋白复合体的结构和功能的理解。为了确保RNaseP继续成为理解RNA结构和功能、大的核糖核蛋白复合体以及从古代RNA世界进化的范例，第三个项目，项目3.RNaseP的结构和生物物理研究，将集中在RNaseP的结构和功能研究上，将其扩展到包括生命的所有三个领域的RNaseP。

 DESCRIPTION (provided by applicant): The central theme of this proposal is structural and mechanistic studies of nucleic acids, proteins, and their interactions. The two broad topics that will serve as foci for our research are: 1) the structure and mechanism of topoisomerases, and 2) the structure, architecture, and mechanism of RNase P. The aim of our work is to discover and explore paradigms that help to illuminate the structure and mechanism of biological molecules common to all three domains of life (bacteria, archaea, and eukaryota). Topoisomerases are ubiquitous proteins found across all three domains of life. They are involved in several cellular processes and the importance of their cellular role is underscored by the fact that they are the target of several cancer chemotherapeutic agents and antibiotics. The study of the structure, mechanism, and function of topoisomerases not only furthers our understanding at many different levels of proteins that interact with DNA and alter its topological properties, but also provides important information to aid in the design of new therapeutic agents. To accomplish our goals, our comprehensive studies of topoisomerases will focus on two large and complementary projects: Project 1. Structural and biochemical studies of type IA, type IC and type II topoisomerases, and Project 2. Single molecule studies of type IA and type II topoisomerases. These two major projects will help answer crucial questions that are needed to advance the field to the next level. RNase P is a ribonucleoprotein complex found in almost all organisms, from bacteria to humans, and responsible for processing many different RNA molecules in the cell. It is composed of one essential RNA subunit and one or more proteins, but in all cases the RNA component is responsible for catalysis. RNase P was one of the first catalytic RNA molecules discovered and its study has been pivotal to our understanding of the role of RNA molecules in catalysis. Our studies of the structure and function of RNase P are providing important and relevant information on a key ribozyme involved in RNA processing in the cell, while also furthering our understanding of the structure and function of large RNA molecules and ribonucleoprotein complexes. To ensure that RNase P continues to be a paradigm for understanding RNA structure and function, large ribonucleoprotein complexes, and also the evolution from the ancient RNA world, a third project, Project 3. Structural and biophysical studies of RNase P, will be centered on structural and functional studies on RNase P expanding it to include RNase Ps from all three domains of life.