Wadzack J, Burkhardt N, Jünemann R, Diedrich G, Nierhaus K H, Frank J, Penczek P, Meerwinck W, Schmitt M, Willumeit R, Stuhrmann H B
Max-Planck-Institut für Molekulare Genetik, AG Ribosomen, Berlin, Germany.
J Mol Biol. 1997 Feb 21;266(2):343-56. doi: 10.1006/jmbi.1996.0788.
A new technique for neutron scattering, the proton-spin contrast-variation, improves the signal-to-noise ratio more than one order of magnitude as compared to conventional techniques. The improved signal enables small RNA ligands within a large deuterated ribonucleic acid-protein complex to be measured. We used this technique to determine the positions of the two tRNAs within the elongating ribosome before and after translocation. Using a four-sphere model for each of the L-shaped tRNAs, unequivocal solutions were found for the localization of the mass centre of both tRNAs. The centre of gravity is located in the interface cavity separating the ribosomal subunits near the neck of the 30 S subunit. It moves during translocation by 12(+/-4) A towards the head of the 30 S subunit and slightly towards the L1 protuberance of the 50 S subunit.
一种新的中子散射技术——质子自旋对比变化法，与传统技术相比，将信噪比提高了一个多数量级。改善后的信号使得能够测量大型氘代核糖核酸 - 蛋白质复合物中的小RNA配体。我们使用该技术确定了转位前后延伸核糖体中两个tRNA的位置。对每个L形tRNA使用四球模型，明确找到了两个tRNA质心的定位解决方案。重心位于30 S亚基颈部附近分隔核糖体亚基的界面腔中。在转位过程中，它向30 S亚基的头部移动12（±4）埃，并略微向50 S亚基的L1突起移动。
