Rodnina M V, Semenkov Iu P, Savelsbergh A, Katunin V I, Peske F, Wilden B, Wintermeyer W
Institute of Physical Biochemistry, University of Witten/Herdecke, 58448 Witten, Germany.
Mol Biol (Mosk). 2001 Jul-Aug;35(4):655-65.
During the translocation step of the elongation cycle of peptide synthesis two tRNAs together with the mRNA move synchronously and rapidly on the ribosome. Translocation is catalyzed by the elongation factor G (EF-G) and requires GTP hydrolysis. The fundamental biochemical features of the process were worked out in the 1970-80s, to a large part by A.S. Spirin and his colleagues. Recent results from pre-steady-state kinetic analysis and cryoelectron microscopy suggest that translocation is a multistep dynamic process that entails large-scale structural rearrangements of both ribosome and EF-G. Kinetic and thermodynamic data, together with the structural information on the conformational changes of the ribosome and of EF-G, provide a detailed mechanistic model of translocation and suggest a mechanism of translocation catalysis by EF-G.
在肽合成延伸循环的转位步骤中，两个tRNA与mRNA一起在核糖体上同步且快速地移动。转位由延伸因子G（EF-G）催化，并且需要GTP水解。该过程的基本生化特征在20世纪70年代至80年代得以阐明，很大程度上是由A.S.斯皮林及其同事完成的。来自稳态前动力学分析和冷冻电子显微镜的最新结果表明，转位是一个多步骤的动态过程，需要核糖体和EF-G都进行大规模的结构重排。动力学和热力学数据，以及关于核糖体和EF-G构象变化的结构信息，提供了一个详细的转位机制模型，并提示了EF-G催化转位的机制。
