Analysis of the acquired microbial defence mechanism against foreign DNA by the CRISPR system

利用CRISPR系统分析微生物对外来DNA的后天防御机制

• 批准号: 150413426
• 负责人: Dr. Ümit Pul
• 金额: --
• 依托单位: EW Nutrition GmbH
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/150413426?language=en
• 关键词: Analysis; acquired; microbial; defence; mechanism

Microbial life is threatened constantly by the invasion of foreign genetic elements, such as phages, transposons or plasmids. Recently, a new defence system has been discovered, which confers inheritable immunity to cells that have survived the invasion of foreign DNA. The system, termed CRISPR, consists of chromosomal arrays of short spacer DNA sequences, originating from the foreign genetic elements, which are separated by palindromic repeats. A siRNA-like mechanism has been assumed to explain resistance to foreign DNA but the molecular details of this defence mechanism are not known. Here we propose the analysis of the basic steps of the CRISPR defence system and its regulation in E. coli. Experiments are suggested to analyze the transcription and processing of the CRISPR elements to short crRNAs and to study the involvement of several Cas proteins in this process. Our main objective is to understand the molecular mechanisms of the crRNA-dependent inactivation of foreign DNA. In our first results we could identify new promoters and characterize several elements of their regulation. The results expected from this proposal are of direct importance for biotechnology and food industries, which use microbial cultures and will have the very useful potential for applications against the spreading of antibiotic resistance.

微生物的生命不断受到外来遗传因素的威胁，如噬菌体、转座子或质粒。最近，一种新的防御系统被发现，它赋予在外来DNA入侵中幸存下来的细胞遗传免疫力。该系统被称为CRISPR，由短间隔DNA序列组成的染色体阵列，起源于外源遗传元素，由回文重复分隔。一种类似siRNA的机制被认为可以解释对外来DNA的抗性，但这种防御机制的分子细节尚不清楚。在这里，我们提出了分析CRISPR防御系统的基本步骤及其在大肠杆菌中的调控。建议通过实验来分析CRISPR元件转录和加工成短crRNA的过程，并研究几种Cas蛋白在这一过程中的参与。我们的主要目的是了解依赖crRNA的外源DNA失活的分子机制。在我们的第一个结果中，我们可以确定新的推动者，并描述他们监管的几个要素。这项提案的预期结果对生物技术和食品工业具有直接重要意义，这些行业使用微生物培养，并将具有非常有用的潜力，用于预防抗生素耐药性的传播。

项目成果

Double-strand DNA end-binding and sliding of the toroidal CRISPR-associated protein Csn2

• DOI: 10.1093/nar/gkt315
• 发表时间: 2013-07-01
• 期刊: NUCLEIC ACIDS RESEARCH
• 影响因子: 14.9
• 作者: Arslan, Zihni;Wurm, Reinhild;Pul, Uemit
• 通讯作者: Pul, Uemit