Integration of Nucleotide Synthesis and DNA Replication in E.coli

对几种细菌的细胞学研究表明，参与DNA复制、修复和染色体浓缩的多种蛋白质在细胞中心高度富集。增加这些蛋白质的局部浓度被认为有助于DNA复制的持续合成能力和效率。从噬菌体感染的细菌细胞到哺乳动物细胞的多条证据表明，在脱氧核苷三磷酸（dNTPs）的合成中涉及多酶复合物，其与DNA复制机制的组分物理相关。虽然这些复合物的偶联是不必要的，但偶联的含义是在复制的活性位点处将存在增加的dNTP浓度，从而使复制叉的效率和稳定性最大化。这项研究的目的是了解必须在空间和时间上控制的过程，以最大限度地提高DNA复制的效率：（i）通过解决核苷酸合成和DNA复制的协调和（ii）通过确定构成或与复制体相关的因素，负责DNA复制的多酶复合物或“工厂”。这些研究的一个关键特征是它们有可能定义与DNA复制相关的蛋白质相互作用网络。了解这些过程对所有细胞都至关重要，因为在所有生物体中，遗传信息从母细胞到子细胞的忠实和准确传递至关重要。此外，复制叉稳定性的丧失可导致叉崩溃，从而导致突变或活力丧失。研究生和本科生是这个研究项目的关键参与者。

Cytological studies in several bacterial species have shown that multiple proteins involved in DNA replication, repair and chromosome condensation are highly enriched at the cell center. Increasing the localized concentration of such proteins is thought to facilitate the processivity and efficiency of DNA replication. Multiple lines of evidence, from phage infected bacterial cells to mammalian cells, indicate that there is a multi-enzyme complex involved in the synthesis of deoxynucleoside triphosphates (dNTPs), physically associated with components of the DNA replication machinery. Although the coupling of these complexes is non-essential, the implication for coupling is that there would be an increased concentration of dNTPs at active sites of replication, maximizing the efficiency and stability of replication forks. This research is aimed at understanding the processes that must be spatially and temporally controlled to maximize the efficiency of DNA replication: (i) by addressing the coordination of nucleotide synthesis and DNA replication and (ii) by identifying factors that constitute or are associated with the replisome, a multi-enzyme complex or 'factory' responsible for DNA replication. A key feature of these studies is that they have the potential to define the protein interaction network associated with DNA replication. Understanding these processes is of fundamental importance to all cells because faithful and accurate transmission of genetic information from mother cell to daughter cell is crucial in all organisms. Additionally, loss of replication fork stability can lead to fork collapse, resulting in mutation or loss of viability. Graduate and undergraduate students are critical participants in this research project.