Mechanistic Studies of Replicative Polymerases

描述（由申请人提供）：细胞复制酶的催化亚基与简单的聚合酶不同，其复杂的模块化结构允许与多种DNA复制蛋白相互作用。我们将以细菌DNA聚合酶III全酶的α亚基为原型，研究这些模块的功能和它们之间的通信。我们将研究与DnaX复合体的β -加工因子和tau“组织者”亚基结合有关的位点，以及在冈崎片段合成过程中使回收成为可能的亲和关系中的相互作用。确定α中epsilon校对亚基的结合位点，并进一步探索整合聚合酶和外切酶活性位点的机制。我们还将确定在复制聚合酶中发现的其他保守结构域和基序的功能。

DESCRIPTION (provided by applicant): The catalytic subunits of cellular replicases are distinguished from simpler polymerases by a complex modular structure that permits interaction with a wide array of DNA replication proteins. Using the alpha subunit of bacterial DNA polymerase III holoenzyme as a prototype, we will study the function of these modules and communication between them. We will investigate the sites involved in binding the beta processivity factor and the tau 'organizer' subunit of the DnaX complex, as well as the interplay in affinities that enables recycling during Okazaki fragment synthesis. The binding sites for the epsilon proofreading subunit within alpha will be determined, and the mechanism used to integrate the polymerase and exonuclease active sites will be further explored. We will also determine the function of other conserved domains and motifs found in replicative polymerases.