Molecular Dissection of Tn7's Targeting of DNA Metabolism

Tn7 靶向 DNA 代谢的分子剖析

• 批准号: 0315316
• 负责人: Joseph Peters
• 金额: --
• 依托单位: Cornell Univ - State: AWDS MADE PRIOR MAY 2010
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-15 至 2007-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0315316&HistoricalAwards=false
• 关键词: Molecular; Dissection; Tn7; Targeting; DNA

This project dissects how the bacterial transposon Tn7 recognizes targets associated with DNA replication and recombination. Transposons are discrete DNA elements that are able to move within the genome of an organism. Transposons are important in the evolution of bacteria and are often responsible for allowing their host organism to live in new environments through resistance to antibiotics and metals or by novel degradation pathways. The transposon Tn7 is of special interest because of its highly evolved ability to select insertion sites associated with active DNA replication. Tn7 uses the element-encoded protein TnsE to preferentially target transposition into plasmids capable of moving between cells by recognizing factors associated with DNA replication. The ability of Tn7 to recognize mobile plasmids as insertion targets likely aids in the dispersal of the element to other bacteria. Tn7 transposition also recognizes structures associated with the repair of DNA double-strand breaks and allows Tn7 to preferentially direct transposition where DNA replication terminates. Work in this project will focus on understanding the various biochemical activities of TnsE and where these activities reside in the protein. In the project, previously identified mutations with increased transposition activity as well as newly isolated TnsE mutations will be dissected. Additional work will determine the molecular process that accounts for the distribution of TnsE-mediated transposition events around induced DNA double-strand breaks. A clear understanding of how Tn7 recognizes certain targets will lead to a better understanding of the role of transposons in evolution and the processes of DNA replication and repair in all living organisms. The utilization of undergraduates is an important component of this research project.

该项目剖析了细菌转座子Tn7如何识别与DNA复制和重组相关的靶标。转座子是能够在生物体基因组内移动的离散DNA元件。转座子在细菌的进化中很重要，并且通常通过对抗生素和金属的抗性或通过新的降解途径使其宿主生物在新的环境中生存。转座子Tn7因其高度进化的选择与活跃DNA复制相关的插入位点的能力而受到特别关注。Tn7利用元件编码蛋白TnsE，通过识别与DNA复制相关的因子，优先靶向转位到能够在细胞间移动的质粒中。Tn7识别移动质粒作为插入目标的能力可能有助于该元素传播到其他细菌。Tn7转位也识别与DNA双链断裂修复相关的结构，并允许Tn7优先指导DNA复制终止的转位。本项目的工作重点是了解TnsE的各种生化活性以及这些活性在蛋白质中的位置。在该项目中，先前鉴定的具有增加转位活性的突变以及新分离的TnsE突变将被解剖。额外的工作将确定在诱导DNA双链断裂周围tnse介导的转座事件分布的分子过程。清楚地了解Tn7如何识别某些靶标将有助于更好地理解转座子在所有生物体的进化和DNA复制和修复过程中的作用。大学生的利用是本研究项目的重要组成部分。