大核糖体亚单元的A 9 A分辨率的X射线晶体图
1Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, USA.
Cell
|July 10, 1998
概括
研究人员绘制了50S核糖体子单元的地图,这对蛋白质合成至关重要. 在9A分辨率下,X射线结晶学揭示了子单元内的双螺旋RNA结构.
科学领域:
- 结构生物学是结构生物学.
- 分子生物学分子生物学
- 生物物理学的生物物理.
背景情况:
- 50S核糖体子单元是蛋白质合成的核心,催化基转移酶反应.
- 了解大型核糖体子单元的结构组织是阐明蛋白质合成机制的关键.
研究的目的:
- 为了生成来自Haloarcula marismortui的50S核糖体子单元的高分辨率X射线晶体电子密度图.
- 为了可视化大型核糖体子单元中的结构成分,特别是RNA.
主要方法:
- 采用X射线晶体学,从50S核糖体子单元晶体中获得衍射数据,达到高达3A的分辨率.
- 20A分辨率的电子显微镜 (EM) 图像被集成到晶格中,以帮助确定相位.
- 差异里叶图被用来定位三个导数中的绑定重原子,验证了EM模型及其位置.
主要成果:
- 在高达9A的分辨率下生成X射线晶体图.
- 在20A分辨率下,X射线图与EM图非常相似.
- 在9A分辨率下,该地图显示了广泛的,分支的,双螺旋式RNA段,右侧扭转,交叉穿越子单元.
结论:
- 这项研究成功地生成了50S核糖体子单元的详细X射线晶体图.
- 这些发现揭示了大型核糖体子单元内的双螺旋RNA的复杂排列,为其结构组织提供了洞察力.
相关概念视频
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02:18X-ray Crystallography
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Diffraction
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01:27Ribosomes
Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that synthesize large quantities of protein—such as secretory cells in the human pancreas—can contain millions of ribosomes.
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within...
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02:53Ribosomal RNA Synthesis
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Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
01:27Ribosomes
Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that synthesize large quantities of protein—such as secretory cells in the human pancreas—can contain millions of ribosomes.
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within...
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within...
01:27Ribosomes
Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that synthesize large quantities of protein—such as secretory cells in the human pancreas—can contain millions of ribosomes.
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within...
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within...