BACTERIAL PROTEINS INVOLVED IN DNA REPAIR

描述（改编自研究者摘要）： 细菌中的同源遗传重组是细菌的非诱变性修复， 在正常生长条件下抑制复制叉。几乎每一 起源于oriC的复制叉在某个时候遇到DNA损伤， 必须经历DNA重组修复。这个过程可能代表了 最复杂的，当然也是最不为人所知的DNA主要途径 修复. GM52725支持的工作目标是全面了解 在这些关键的修复途径中，复制和重组 系统紧密结合。提出了五个具体目标。第一、 DNA重组中涉及的几种蛋白质的基础生物化学 将探讨修复，重点是RecF，RecO，RecR和RecG蛋白。 第二，多种重组蛋白与RecA的相互作用 蛋白质将被探索。这项工作将集中在RecG蛋白，沿着 与RuvA和RuvB蛋白质结合。在第三个目标中，DNA底物将是 构建以模拟可能出现的至少一种所提出的DNA结构， 被逮捕的复制叉然后他们将确定这些DNA 结构由重组酶处理，包括RuvAB复合物， RecG蛋白和RecA蛋白。为了进一步阐明 当它们遇到DNA损伤时，复制叉，第四个目的是检查 复制叉生物化学系统地使用DNA底物 不同类型的DNA损伤嵌入特定位点。最后一个目标是 通过DNA聚合酶V检测DNA损伤的致突变复制旁路 体外这些实验的目的是重建部分的建议， 复制叉重新激活的途径，以进一步实现 用纯化的酶完全重构。

DESCRIPTION (adapted from the investigator's abstract): The primary function of homologous genetic recombination in bacteria is the nonmutagenic repair of arrested replication forks under normal growth conditions. Virtually every replication fork originating at oriC encounters DNA damage at some point, and must undergo recombinational DNA repair. This process represents perhaps the most complex and certainly the least understood of the major pathways for DNA repair. The goal of the work supported by GM52725 is a complete understanding of these critical repair pathways, where the replication and recombination systems are closely integrated. Five specific aims are proposed. First, fundamental biochemistry of several proteins involved in recombinational DNA repair will be explored, focusing on the RecF, RecO, RecR, and RecG proteins. Second, the interaction of a variety of recombination proteins with RecA protein will be explored. This effort will focus on the RecG protein, along with the RuvA and RuvB proteins. In the third aim, DNA substrates will be constructed to mimic at least one of the proposed DNA structures that may occur at arrested replication forks. They will then determine how these DNA structures are processed by recombination enzymes, including the RuvAB complex, the RecG protein, and the RecA proteins. To further elucidate the fate of replication forks when they encounter DNA damage, a fourth aim is to examine the biochemistry of replication fork arrest systematically, using DNA substrate with different types of DNA damage embedded site-specifically. The last aim is to examine the mutagenic replicative bypass of DNA lesions by DNA polymerase V in vitro. These experiments are designed to reconstitute parts of the proposed pathways for replication fork reactivation, to further the ultimate goal of a complete reconstitution with purified enzymes.