Gao Haixiao, Sengupta Jayati, Valle Mikel, Korostelev Andrei, Eswar Narayanan, Stagg Scott M, Van Roey Patrick, Agrawal Rajendra K, Harvey Stephen C, Sali Andrej, Chapman Michael S, Frank Joachim
Howard Hughes Medical Institute, Health Research, Inc, Empire State Plaza, Albany, NY 12201, USA.
Cell. 2003 Jun 13;113(6):789-801. doi: 10.1016/s0092-8674(03)00427-6.
Cryo-EM density maps showing the 70S ribosome of E. coli in two different functional states related by a ratchet-like motion were analyzed using real-space refinement. Comparison of the two resulting atomic models shows that the ribosome changes from a compact structure to a looser one, coupled with the rearrangement of many of the proteins. Furthermore, in contrast to the unchanged inter-subunit bridges formed wholly by RNA, the bridges involving proteins undergo large conformational changes following the ratchet-like motion, suggesting an important role of ribosomal proteins in facilitating the dynamics of translation.
利用实空间精修分析了冷冻电镜密度图，该图展示了处于两种不同功能状态的大肠杆菌70S核糖体，这两种状态通过类似棘轮的运动相关联。对由此得到的两个原子模型进行比较表明，核糖体从紧密结构转变为较松散的结构，同时许多蛋白质也发生了重排。此外，与完全由RNA形成的亚基间桥未发生变化不同，涉及蛋白质的桥在类似棘轮的运动后发生了较大的构象变化，这表明核糖体蛋白在促进翻译动力学方面发挥着重要作用。
