MITOCHONDRIAL DNA POLYMERASE--MECHANISM AND STRUCTURE

拟议工作的长期目标是阐明 动物线粒体中DNA复制机制的研究。 这可能是 当纯化的酶在体外重构以产生 能够起始和延伸DNA的复制复合物 合成. 这些研究将提供研究框架， 确定这些过程在体内发生时的调节。 目前的建议集中在主要的复制酶， 线粒体DNA聚合酶γ一种综合办法， 生物化学、免疫学和分子生物学方法将是 进行机械和结构功能分析， 线粒体DNA聚合酶，并完成和过度生产其两个 亚单位。 第二个目标是分离线粒体RNA 聚合酶/ DNA引物酶和RNA配位的检测 启动和DNA合成的线粒体DNA模板。 正常情况下动物细胞繁殖的控制 发展，以及在癌症发展过程中失去控制， 在人类生长、衰老和疾病的过程中至关重要。 在每次细胞分裂之前，每个细胞的DNA互补物都是 复制的 因为DNA复制和细胞分裂 再加上对DNA复制机制的理解 在动物细胞中的功能对于我们理解这些 基本过程。 线粒体的生物合成与细胞的 增殖，但它既不与线粒体DNA紧密结合， 也不影响细胞周期。 尽管如此，因为DNA 细胞内线粒体的数量 保持相对恒定，可能存在特定的调节机制 需要将线粒体DNA复制和生物发生耦合到 核DNA复制和细胞分裂。 详细分析 参与线粒体DNA复制的关键酶，γ聚合酶， 将为最终理解 线粒体生物发生

The long term objective of the proposed work is the elucidation of the mechanism of DNA replication in animal mitochondria. This may be accomplished when purified enzymes are reconstituted in vitro to yield replication complexes capable of initiation and elongation of DNA synthesis. The studies will provide the framework for research to determine the regulation of these processes as they occur in vivo. The current proposal focuses on the major replicative enzyme in mitochondria, DNA polymerase gamma. A combined approach involving biochemical, immunological and molecular biological methods will be employed to undertake mechanistic and structure-function analysis of the mitochonchial DNA polymerase and to done and overproduce its two subunits. Secondary goals involve isolation of a mitochondrial RNA polymerase / DNA primase and examination of the co-ordination of RNA priming and DNA synthesis on mitochondrial DNA templates. The control of animal cell reproduction during normal development, and the loss of control during cancerous development, is of central importance in the processes of human growth, aging, and disease. Prior to every cell division, the DNA complement of each cell is duplicated. Because DNA replication and cell division are tightly coupled, an understanding of the mechanisms of DNA replication functioning in animal cells is essential to our understanding of these basic processes. Mitochondrial biogenesis proceeds in parallel with cell proliferation, but it is neither tightly coupled to mitochondrial DNA replication nor to the cell cycle. Nevertheless, because both the DNA content of the mitochondrion and the number of mitochondria in cells remain relatively constant, specific regulatory mechanisms are likely required to couple mitochondrial DNA replication and biogenesis to nuclear DNA replication and cell division. A detailed analysis of the key enzyme involved in mitochondrial DNA replication, gamma polymerase, will represent a major contribution toward an eventual understanding of mitochondrial biogenesis.