Mechanism of Homologous Recombination in Archaea

同源重组是修复暴露于化学诱变剂和辐射引起的双链断裂的主要机制。 修复这些断裂是进化的必要条件，并确保信息在一代又一代之间正确传递而不会丢失。对这一过程的一般理解主要来自细菌或真核生物分支的研究。 很少有人知道双链断裂修复的第三个，古菌分支。 古细菌在物理上类似于细菌，但使用一些似乎更像真核生物的细胞方法。 在这些类似真核生物的过程中，关键是基因组维护的方法，包括双链断裂修复。这提供了一个独特的机会，研究同源重组机制在进化上不同的一组生物体。 该项目的总体目标是使用成熟的古细菌模型硫磺硫化叶菌来确定三种蛋白质的机械作用，这三种蛋白质与链交换蛋白RadA的序列相关。 对这些旁系同源物的研究将涉及研究生、本科生和高中生，使用两种互补但独立的方法：1）将单独测定蛋白质的体外生化活性，并与其他已知的重组相关蛋白质组合，其中将建立它们在修复途径中的相互作用和功能点; 2）旁系同源物在体内的作用将通过研究辐射损伤后的蛋白质持久性和测量野生型和野生型中的染色体修复率来评估。型和突变株的背景。这个项目的重点是一个机制，细胞生存所必需的DNA损伤后，在一个成员的最好的研究生命的分支。 除了更多地了解所有细胞修复DNA的方式外，这项工作还有望为同源重组的调控和基因组稳定性的维持提供新的全面见解。 这些研究是多学科的，使用生物化学，遗传学和细胞的方法，将为学生在不同的教育阶段提供广泛的实验室教育。具体而言，该项目为一名研究生和两名本科生提供实验室培训，并特别强调扩大招聘代表性不足的少数民族学生。 此外，两名高中生将通过暑期实习获得支持，这将为处于职业生涯早期阶段的年轻科学家提供宝贵的研究经验。

Homologous recombination is a major mechanism for repair of double-strand breaks caused by exposure to chemical mutagens and radiation. Repair of these breaks is an evolutionary imperative and ensures proper transfer of information from generation to generation without information loss. General understanding of this process has come mostly from studies from the bacterial or eukaryotic branches of life. Very little is known about double-strand break repair in the third, archaeal branch. Archaea physically resemble bacteria, but use some cellular approaches to life that seem to be more eukaryotic. Key among these eukaryotic-like processes are methods of genome maintenance, including double-strand break repair. This provides a unique opportunity to study homologous recombination mechanisms in an evolutionarily distinct group of organisms. The overall objective of this project is to use the well established archaeal model Sulfolobus solfataricus to determine the mechanistic role of three proteins that are related by sequence to the strand-exchange protein, RadA. The research on these paralogues will involve graduate, undergraduate, and high school students using two complementary but independent approaches: 1) Biochemical activity of the proteins in vitro will be determined individually and in combination with other known recombination-related proteins, where their interactions and point of function in the repair pathway will be established; 2) Roles of the paralogues in vivo will be assessed through studies of protein persistence after radiation damage and measurement of chromosomal repair rates in both wild-type and mutant strain backgrounds.This project focuses on a mechanism necessary for cellular survival following DNA damage in a member of the least well studied branch of life. In addition to understanding more about the way in which all cells repair their DNA, this work is expected to provide new overall insight into the regulation of homologous recombination and maintenance of genome stability. These studies are multidisciplinary, using biochemical, genetic, and cellular approaches that will provide a broad laboratory education for students at various educational stages. Specifically, this project provides laboratory training for one graduate and two undergraduate students, with a special emphasis on outreach recruiting of underrepresented minority students. Additionally, two high school students will be supported through summer internships, which will offer a valuable research experience to young scientists at early stages in their careers.