MECHANISM OF TERMINATION OF DNA REPLICATION

DNA复制调控机制及其作用机制的研究 与细胞分裂的协调对细胞增殖具有明显的重要性 比如癌症。我很重要，但还不完全理解这一步 更大的问题是复制终止的机制和控制， 以及它与细胞分裂的可能联系。利用E.Coli和B. 以枯草杆菌和耐药质粒R6K为模型系统，我们提出 研究终止剂的作用机制及调控 蛋白质。具体地说，我们建议研究分子基础 TER蛋白反螺旋酶活性的极性 基因和生物化学相结合的方法。 我们最近发现，TER蛋白的活性是 由特定的蛋白质-蛋白质相互作用调节的新的 抗终止子蛋白。我们建议克隆、过度生产和提纯 均一抗TER蛋白，并研究其生物化学和 它与TER蛋白相互作用的生理后果。 最后，我们已经结晶了枯草杆菌的TERβ蛋白， 晶体的衍射率为2.5A。我们建议解决 不光是脱脂蛋白的结构，还有蛋白质-DNA的结构 很复杂。

The study of the mechanism of regulation of DNA replication and its coordination wit cell division is of obvious importance proliferation such as cancer. Am important, but incompletely understood step of this larger problem is the mechanism and control of replication terminating, and its possible link to cell division. Utilizing E. coli and B. subtilis and the drug resistance plasmid R6K as model systems, we propose to study the mechanism of action and regulation of the terminator proteins. Specifically, we propose to investigate the molecular basis of the polarity of the contrahelicase activities of ter proteins by combined genetic and biochemical approaches. We have recently discovered that the activity of the ter protein is modulated by specific protein-protein interaction with a novel antiterminator protein. We propose to clone, overproduce and purify to homogeneity the anti-ter protein, and to study the biochemistry and physiological consequences of its interaction with the ter protein. Finally, we have crystallized the ter beta protein (RTP) of B. subtilis, and the crystals diffract to a resolution of 2.5A. We propose to solve not only the structure of the apoprotein but also that of the protein-DNA complex.