A MODEL OF PROTEIN-SYNTHESIS BASED ON CRYOELECTRON MICROSCOPY OF THE E-COLI RIBOSOME
A MODEL OF PROTEIN-SYNTHESIS BASED ON CRYOELECTRON MICROSCOPY OF THE E-COLI RIBOSOME
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DOI：
10.1038/376441a0
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发表时间：
1995-08-03
期刊：
影响因子：
64.8
通讯作者：
AGRAWAL, RK
中科院分区：
文献类型：
--
作者：
FRANK, J;ZHU, J;AGRAWAL, RK
核糖体由蛋白质和核酸组装而成，并根据所有生物体的遗传指令合成蛋白质。这个基本过程的许多生化步骤是已知的，但详细的理解需要一个明确的核糖体结构模型。电子显微镜结合二维晶体或单个核糖体的图像重建（4）是最有前途的技术，但所得模型的分辨率不足。在这里，我们报告了一个25埃重建的核糖体从大肠杆菌，获得了结合4,300个预测的冰嵌入单颗粒。我们的新的重建揭示了一个通道中的小核糖体亚基和一个分叉的隧道中的大亚基，这可能构成传入的信息和新生的多肽链，分别的途径。基于这些新的发现，蛋白质合成的基本框架的三维模型。
THE ribosome is formed by assembly of proteins and nucleic acids, and synthesizes proteins according to genetic instructions in all organisms. Many of the biochemical steps of this fundamental process are known, but a detailed understanding requires a well-defined structural model of the ribosome. Electron microscopy combined with image reconstruction of two-dimensional crystals or single ribosomes(4) has been the most promising technique, but the resolution of the resulting models has been insufficient. Here we report a 25-Angstrom reconstruction of the ribosome from Escherichia coli, obtained by combining 4,300 projections of ice-embedded single particles. Our new reconstruction reveals a channel in the small ribosomal subunit and a bifurcating tunnel in the large subunit which may constitute pathways for the incoming message and the nascent polypeptide chain, respectively. Based on these new findings, a three-dimensional model of the basic framework of protein synthesis is presented.