INVESTIGATION INTO THE STRUCTURAL MECHANISM OF ALLOSTERIC MODULATION OF DNA CLEA

DNA CLEA 变构调节的结构机制研究

• 批准号: 8362411
• 负责人: Nancy C Horton
• 金额: $ 0.03万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8362411
• 关键词: Bacteriophages; Binding; Cleaved cell; DNA; DNA Sequence; Enzymes; Funding; Genome; Grant; Invaded; Investigation; Metabolism; National Center for Research Resources; Principal Investigator; Radiation; Research; Research Infrastructure; Resources; Site; Source; Structure; United States National Institutes of Health; cost; endonuclease; pressure; recombinational repair; structural biology; three dimensional structure

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. We are investigating the structure of an endonuclease, SgrAI, bound to its target DNA. Endonucleases are important enzymes involved in all aspects of DNA metabolism including replication, recombination, and repair. SgrAI serves to protect its host from invading phage DNA, and oligomerizes on DNA causing sequestration of the activated SgrAI enzyme. Activated SgrAI, caused by oligomerization, cleaves primary site DNA sequences 200 fold faster than the unactived form, and also cleaves more efficiently at secondary site DNA sequences. The secondary sites are not protected in the host DNA, and cleavage by SgrAI would result in genome damage to the host, resulting in strong selective pressure to sequestration of activated SgrAI enzymes. The oligomerization interfaces, and the structures of both activated and unactivated forms of SgrAI, are investigated for their three dimensional structures.

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供。子项目的主要支持 并且子项目的主要研究者可能是由其他来源提供的， 包括其他 NIH 来源。 子项目可能列出的总成本 代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。 我们正在研究与其靶 DNA 结合的核酸内切酶 SgrAI 的结构。 核酸内切酶是参与 DNA 代谢各个方面（包括复制、重组和修复）的重要酶。 SgrAI 用于保护其宿主免受噬菌体 DNA 的入侵，并在 DNA 上寡聚，导致激活的 SgrAI 酶的隔离。 由寡聚化引起的激活的 SgrAI 切割一级位点 DNA 序列的速度比未激活形式快 200 倍，并且在二级位点 DNA 序列上的切割效率也更高。 宿主 DNA 中的二级位点不受保护，SgrAI 的切割会导致宿主基因组损伤，从而对激活的 SgrAI 酶的隔离产生强大的选择压力。 研究了 SgrAI 的低聚界面以及激活和未激活形式的结构的三维结构。