UmuD'蛋白的结构及其对DNA损伤的反应调节
T S Peat1, E G Frank, J P McDonald
1Deparment of Biochemistry and Molecular Biophysics, Columbia University, NY 10032, USA.
Nature
|April 25, 1996
概括
对DNA修复的耐受性对生命至关重要. 研究人员研究了 UmuD.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 结构生物学 结构生物学
背景情况:
- 生命需要容忍DNA修复错误,当遗传信息被掩盖时.
- 大肠杆菌的SOS反应是对DNA损伤的调节系统.
- 专门的蛋白质能够通过病变进行DNA复制,尽管其可靠性降低.
研究的目的:
- 阐明参与细菌DNA修复的 UmuD' 蛋白质的结构基础.
- 获取有关大肠杆菌SOS响应机制的详细见解.
主要方法:
- 使用X射线晶体学以2.5A分辨率确定大肠杆菌Umud'蛋白质的结构.
主要成果:
- 晶体结构揭示了 UmuD' 蛋白质通过球状头形成二极体,具有不寻常的Beta结构.
- 延伸的氨基末尾结合在一起,形成结晶的纤维.
- 该结构为UmuD类蛋白质的自我分裂反应机制提供了洞察力.
结论:
- UmuD'的确定的结构提供了对其在SOS响应中的作用的机制理解.
- 结构洞察力有助于理解细菌如何在复制过程中耐受DNA损伤.
相关概念视频
Nucleotide Excision Repair
Overview
Overview of DNA Repair
In order to be passed through generations, genomic DNA must be undamaged and error-free. However, every day, DNA in a cell undergoes several thousand to a million damaging events by natural causes and external factors. Ionizing radiation such as UV rays, free radicals produced during cellular respiration, and hydrolytic damage from metabolic reactions can alter the structure of DNA. Damages caused include single-base alteration, base dimerization, chain breaks, and cross-linkage.
Chemically...
Chemically...
Nucleotide Excision Repair
Overview
Overview of DNA Repair
In order to be passed through generations, genomic DNA must be undamaged and error-free. However, every day, DNA in a cell undergoes several thousand to a million damaging events by natural causes and external factors. Ionizing radiation such as UV rays, free radicals produced during cellular respiration, and hydrolytic damage from metabolic reactions can alter the structure of DNA. Damages caused include single-base alteration, base dimerization, chain breaks, and cross-linkage.
Chemically...
Chemically...
Nucleotide Excision Repair
DNA Distortion and Damage
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
DNA Damage Can Stall the Cell Cycle
In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...


