BACTERIAL PROTEINS INVOLVED IN DNA REPAIR

描述(改编自调查人员的摘要)：的主要功能 细菌中的同源基因重组是非诱变修复 在正常生长条件下，复制叉子受阻。几乎每一个人 起源于ORIC的复制分叉在某个时间点遇到DNA损坏，并且 必须进行重组DNA修复。这一过程可能代表了 最复杂的，当然也是最不被了解的DNA的主要途径 修理。GM52725支持的工作目标是完全理解 在这些关键修复途径中，复制和重组 系统紧密集成在一起。提出了五个具体目标。第一, 参与重组DNA的几种蛋白质的基础生物化学 将探索修复，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 我们将探索蛋白质。这项工作将集中在RecG蛋白上，以及 Ruva和RuvB蛋白。在第三个目标中，DNA底物将是 被构建为模仿可能出现的至少一个提议的DNA结构 在被逮捕的复制叉子。然后他们将确定这些DNA是如何 结构由重组酶处理，包括RuvAB复合体， RecG蛋白和RecA蛋白。为了进一步阐明……的命运 复制分叉当它们遇到DNA损伤时，第四个目标是检查 利用DNA底物系统地研究复制分叉抑制的生物化学 有不同类型的DNA损伤嵌入特定部位。最后一个目标是 DNA聚合酶V检测DNA损伤的致突变复制旁路 在试管中。这些实验旨在重新构建建议的部分 复制分叉重新激活的途径，以进一步实现 用纯化的酶完全重组。

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.