在2.8A分辨率的met压缩机-操作器复合体的晶体结构揭示了β-链的DNA识别
1Department of Biochemistry and Molecular Biology, University of Leeds, UK.
Nature
|October 1, 1992
概括
甲基抑制蛋白通过将β丝带插入大槽来结合DNA,形成与基对的键. 它还检测到DNA骨干灵活性,用于精确的序列识别.
科学领域:
- 结构生物学 结构生物学
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
背景情况:
- 甲基抑制剂是一个关键的转录调节器.
- 了解蛋白质-DNA相互作用对于基因调节至关重要.
- 抑制剂的特定结合机制决定了基因表达控制.
研究的目的:
- 为了阐明美特抑制器与其操作者DNA之间的原子级相互作用.
- 为了确定met压缩机-操作器复合体中序列特异性的结构基础.
- 研究超越直接基对相互作用的新型识别机制.
主要方法:
- 使用X射线晶体学来确定met压缩机-操作器复合体的3D结构.
- 详细的结构分析侧重于蛋白质-DNA接口.
- 识别键和DNA骨干相互作用.
主要成果:
- 两个二维的抑制分子在一个18个基对的DNA片段上结合相邻的位点.
- 反平行蛋白β条纹插入B型DNA的主要槽.
- 在抑制性氨基酸和DNA基对之间形成直接的键.
- 抑制器识别了依赖序列的DNA骨干扭曲和灵活性.
结论:
- 甲基抑制器通过通过β-带相互作用的直接基对识别来实现序列特异性.
- 抑制器能够感知DNA骨干构造的能力提供了一个额外的特异性层.
- 这种双重识别机制确保了对目标操作员序列的高保真性绑定.
相关概念视频
The DNA Helix
Overview
DNA as a Genetic Template
Two structural features of the DNA molecule provide a basis for the mechanisms of heredity: the four nucleotide bases and its double-stranded nature. The Watson-Crick model of double-helical DNA structure, proposed in 1952, drew heavily upon the X-ray crystallography work of researchers Rosalind Franklin and Maurice Wilkins. Watson, Crick, and Wilkins jointly received the Nobel Prize in Physiology or Medicine for their work in 1962. Franklin was, controversially, excluded from the prize for...
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The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
Cooperative Binding of Transcription Regulators
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that...
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The DNA Helix
Deoxyribonucleic acid, or DNA, is the genetic material responsible for passing traits from generation to generation in all organisms and most viruses. DNA is composed of two strands of nucleotides that wind around each other to form a spring-like structure called a double helix. However, the double helix is not perfectly symmetrical. Instead, there are regularly occurring grooves in the structure. The major groove occurs where the sugar-phosphate backbones are relatively far apart. This space...


