Structural and Functional Analysis of the Initiation of DNA Replication in Bacteria

细菌 DNA 复制起始的结构和功能分析

• 批准号: 0423894
• 负责人: David Jeruzalmi
• 金额: $ 30万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-11-01 至 2006-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0423894&HistoricalAwards=false
• 关键词: Structural; Functional; Analysis; Initiation; DNA

The long-term goal of this research is a detailed understanding of the structure and mechanism of action of the macromolecular complexes, which operate at the bacterial origin of DNA replication. Cells initiate replication of chromosomal DNA by assembling large protein complexes at specialized sites termed origins of DNA replication. The complexes at the origin undergo remodeling through the recruitment and dissociation of factors and eventually mature into a pair of fully formed replication forks. In bacteria, the first to protein to bind to the origin is the DnaA protein, five monomers of which interact at distinct sites and form a large nucleo-protein complex. The architecture of this complex is poorly understood. With ATP, this complex promotes the unwinding of regions of the DNA duplex at the origin, which enables loading of the DnaB replicative helicase (assisted by the DnaC protein). Parallels between the assemblies that operate at the origins of DNA replication in bacteria, archaea and eukaryotes are indicated by common mechanistic details and by amino acid sequence similarities in the constituent proteins. These parallels strongly suggest that common structural principles will emerge from studies with the less complicated replication systems offered by bacteria. The PI will perform biochemical, biophysical and structural studies to understand the role of the DnaA protein in the initiation of DNA replication in bacteria. Although the current state of understanding is advanced, several intriguing questions remain unanswered about the architecture and mechanism of action of the DnaA assembly at the origin of DNA replication. This research will be integrated into the scientific and educational activities being performed by the PI within the Department of Molecular and Cellular Biology at Harvard University. These include the education of graduate and undergraduate students and the training of post-doctoral fellows in the fields of experimental biochemistry and structural biology.

这项研究的长期目标是详细了解大分子复合物的结构和作用机制，这些复合物在DNA复制的细菌起点起作用。细胞通过在称为DNA复制起点的专门位点组装大蛋白复合物来启动染色体DNA的复制。在起源处的复合物通过因子的募集和解离进行重塑，并最终成熟为一对完全形成的复制叉。在细菌中，第一个与蛋白质结合的是DnaA蛋白，它的五个单体在不同的位点相互作用，形成一个大的核蛋白复合物。这个建筑群的结构还不太清楚。在ATP的作用下，该复合物促进DNA双链体在起点的区域解旋，这使得能够加载DnaB复制解旋酶（由DnaC蛋白辅助）。在细菌、古生菌和真核生物中，在DNA复制的起点处操作的组装体之间的相似性由共同的机械细节和组成蛋白质中的氨基酸序列相似性来指示。这些相似之处有力地表明，共同的结构原则将从细菌提供的不太复杂的复制系统的研究中出现。PI将进行生物化学，生物物理和结构研究，以了解DnaA蛋白在细菌DNA复制启动中的作用。虽然目前的理解是先进的，一些有趣的问题仍然没有答案的架构和机制的DnaA大会在DNA复制的起点。本研究将纳入哈佛大学分子和细胞生物学系PI开展的科学和教育活动。 其中包括实验生物化学和结构生物学领域的研究生和本科生教育以及博士后研究员的培训。