Repair of Damaged Chromosomes Mediated by the Bacterial RecN Protein

细菌 RecN 蛋白介导的受损染色体修复

• 批准号: 8694055
• 负责人: SHELLEY LUSETTI
• 金额: $ 26.28万
• 依托单位: NEW MEXICO STATE UNIVERSITY LAS CRUCES
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-05 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8694055
• 关键词: ATP Hydrolysis; ATP phosphohydrolase; Affinity; Bacteria; Bacterial Genome; Binding; Biochemical; Biochemistry; Biological; Catalysis; Chromosomal Instability; Chromosomal Rearrangement; Chromosome Deletion; Chromosomes; Congenital Abnormality; DNA; DNA Binding; DNA Double Strand Break; DNA Repair; DNA Repair Pathway; DNA-dependent ATPase; Data; Double Strand Break Repair; Genetic; Genetic Recombination; Genetic Screening; Genome; Goals; Housekeeping; Housing; Hydrolysis; In Vitro; Investigation; Kinetics; Lead; Maintenance; Malignant Neoplasms; Mediating; Metabolism; Modeling; Molecular; Mutation; Nucleotides; Organism; Orthologous Gene; Pathway interactions; Physical condensation; Pilot Projects; Play; Point Mutation; Positioning Attribute; Premature aging syndrome; Process; Property; Protein Family; Proteins; Reaction; Rec A Recombinases; Research Proposals; Role; Sister Chromatid; Substrate Specificity; Tumor Suppressor Proteins; Work; biophysical properties; cohesin; cohesion; ds-DNA; in vitro activity; in vivo; member; mutant; nucleotide analog; public health relevance; recombinase; recombinational repair; reconstitution; repaired

DESCRIPTION (provided by applicant): The overall goal of this research proposal is to reveal the molecular function of RecN, a protein critical to the repair of DNA double-stranded breaks (DSBs) in bacteria. Bacterial RecN proteins share significant homology to the Structural Maintenance of Chromosomes (SMC) family of proteins. Eukaryotic SMC proteins have essential (although not fully understood) housekeeping and tumor suppressor roles in a variety of DNA metabolic processes such as chromosomal condensation, sister chromatid cohesion and recombinational DNA repair. Although extensive genetic evidence underscores the importance of RecN proteins to bacterial genome maintenance, there has been little substantive biochemical investigation into their function and, consequently, the specific reactions requiring RecN have not been identified. We have successfully identified several in vitro activities mediated by the RecN protein including a cohesin function and the stimulation of recombination. We are now positioned to decipher mechanistic details of RecN function in recombinational DNA repair pathways, utilizing a combination of biochemical, biophysical and biological approaches. This project has three specific aims. First, we will further characterize the biochemical and biophysical properties of the RecN protein related to substrate binding and catalysis. Next, we will determine the role of RecN in mediating recombinational repair by using both in vitro pathway reconstitution and genetic screens. And, finally, we will determine the contribution of multiple sequence motifs conserved in all bacterial RecN proteins and shared by eukaryotic SMC orthologs. We anticipate that the results from this work will provide valuable models for understanding the molecular role that eukaryotic SMC proteins play in genome maintenance.

描述（由申请人提供）：本研究计划的总体目标是揭示 RecN 的分子功能，RecN 是一种对修复细菌 DNA 双链断裂 (DSB) 至关重要的蛋白质。细菌 RecN 蛋白与染色体结构维持 (SMC) 家族蛋白具有显着的同源性。真核 SMC 蛋白在染色体浓缩、姐妹染色单体凝聚和重组 DNA 修复等多种 DNA 代谢过程中具有重要的（尽管尚未完全了解）管家和肿瘤抑制作用。尽管大量的遗传证据强调了 RecN 蛋白对细菌基因组维护的重要性，但对其功能的实质性生化研究却很少，因此，需要 RecN 的特定反应尚未确定。我们已经成功鉴定了 RecN 蛋白介导的几种体外活性，包括粘连蛋白功能和重组刺激。我们现在致力于结合生物化学、生物物理和生物学方法，破译重组 DNA 修复途径中 RecN 功能的机制细节。该项目有三个具体目标。首先，我们将进一步表征 RecN 蛋白与底物结合和催化相关的生化和生物物理特性。接下来，我们将通过体外途径重建和遗传筛选来确定 RecN 在介导重组修复中的作用。最后，我们将确定所有细菌 RecN 蛋白中保守且由真核 SMC 直向同源物共享的多个序列基序的贡献。我们预计这项工作的结果将为理解真核 SMC 蛋白在基因组维护中发挥的分子作用提供有价值的模型。