A 9Å resolution x-ray crystallographic map of the large ribosomal subunit
A 9Å resolution x-ray crystallographic map of the large ribosomal subunit
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DOI：
10.1016/s0092-8674(00)81455-5
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发表时间：
1998-06-26
期刊：
影响因子：
64.5
通讯作者：
Steitz, TA
中科院分区：
文献类型：
--
作者：
Ban, N;Freeborn, B;Steitz, TA
核糖体的 50S 亚基催化蛋白质合成的肽基转移酶反应。我们使用衍射至 3 埃的晶体数据，生成了 Haloarcula marismortui 的大核糖体亚基的 X 射线晶体电子密度图，分辨率高达 9 埃。将这些粒子的 20 埃分辨率 EM 图像定位在晶格中，产生的相足够精确，可以使用差分傅里叶图定位三个导数中的束缚重原子，从而证明 EM 模型及其在晶胞中的位置的正确性。在 20 埃分辨率下，X 射线图与 EM 图类似；然而，在 9 埃时，它显示出长、连续但有分支的特征，其形状、直径和右旋扭曲与交叉亚基的双螺旋 RNA 片段一致。
The 50S subunit of the ribosome catalyzes the peptidyl-transferase reaction of protein synthesis. We have generated X-ray crystallographic electron density maps of the large ribosomal subunit from Haloarcula marismortui at various resolutions up to 9 Angstrom using data from crystals that diffract to 3 Angstrom. Positioning a 20 Angstrom resolution EM image of these particles in the crystal lattice produced phases accurate enough to locate the bound heavy atoms in three derivatives using difference Fourier maps, thus demonstrating the correctness of the EM model and its placement in the unit cell. At 20 Angstrom resolution, the X-ray map is similar to the EM map; however, at 9 Angstrom it reveals long, continuous, but branched features whose shape, diameter, and right-handed twist are consistent with segments of double-helical RNA that crisscross the subunit.