The Biochemistry of Genetic Recombination/RecA Protein

描述(申请人提供)：大肠杆菌的RecA蛋白在体外促进DNA链交换反应，为同源基因重组的中心步骤提供了一个方便的分子模型。这种蛋白质是在所有生物体中发现的重组酶家族的原型。在人类中，主要的RecA同源物(HRad51)是抑制肿瘤的主要途径的一部分。这项提案中研究的长期目标是详细了解RecA蛋白的调节和功能。假设停滞不前的复制叉的重组DNA修复是RecA蛋白的主要功能，这提供了一个智力框架。该项目已经进化到包括大肠杆菌和耐辐射葡萄球菌的RecA蛋白，以及酵母的RAD51蛋白。有四个主要的重点领域：(A)结构-功能关系，(B)RecA家族重组酶的一般生物化学，(C)RecA的调控，(D)RecA蛋白的特殊功能。结构-职能努力集中在两个倡议上。首先，我们正在研究一些突变的RecA蛋白，在这些蛋白中，ATP水解与一个或多个功能的耦合被破坏。我们也有几个项目来阐明RecA蛋白与DNA结合的结构。生化研究主要集中在重组酶细丝的组装和拆解，DNA配对和链交换，以及ATP水解酶在重组酶反应中的作用。对RecA蛋白的调控工作包括研究RecFOR、RecX、DINL、REC1、RdgC、UvrD和PsiAB蛋白的功能。研究中的RecA的特殊功能包括由RecA刺激的DNA聚合酶V的跨损伤DNA合成反应，并可能扩展到包括理解DNA交联修复的新努力。

DESCRIPTION (provided by applicant): The RecA protein of E. coli promotes a DNA strand exchange reaction in vitro that provides a convenient molecular model for the central steps of homologous genetic recombination. This protein is the prototype for a family of recombinases found in all organisms. In humans, the primary RecA homologue (hRad51) is part of a major pathway for tumor suppression. The long-range goal of the research in this proposal is a detailed understanding of the regulation and function of RecA protein. The hypothesis that recombinational DNA repair of stalled replication forks is the primary function of RecA protein provides an intellectual framework. The project has evolved to include the RecA proteins of E. coli and D. radiodurans, as well as the Rad51 protein of yeast. There are four major areas of emphasis: (a) structure-function relationships, (b) general biochemistry of RecA family recombinases, (c) regulation of RecA, and (d) special functions of RecA protein. Structure-function efforts are focused on two initiatives. First, we are examining a number of mutant RecA proteins in which the coupling of ATP hydrolysis to one or more functions is disrupted. We also have several projects to elucidate the structure of RecA protein bound to DNA. Biochemical studies are focused on recombinase filament assembly and disassembly, DNA pairing and strand exchange, and the role of ATP hydrolysis in recombinase reactions. The work on the regulation of RecA protein includes efforts to investigate the function of the RecFOR, RecX, Dinl, RecL, RdgC, UvrD, and PsiAB proteins. Special functions of RecA under investigation include the RecA-stimulated translesion DNA synthesis reaction of DNA polymerase V, and may be extended to include a new effort to understand DNA crosslink repair.