Fraser Christopher S, Doudna Jennifer A
Department of Molecular and Cell Biology & Department of Chemistry, Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA, USA.
Q Rev Biophys. 2007 May;40(2):163-89. doi: 10.1017/S0033583507004647.
The ribosome is a dynamic machine that undergoes many conformational rearrangements during the initiation of protein synthesis. Significant differences exist between the process of protein synthesis initiation in eubacteria and eukaryotes. In particular, the initiation of eukaryotic protein synthesis requires roughly an order of magnitude more initiation factors to promote efficient mRNA recruitment and ribosomal recognition of the start codon than are needed for eubacterial initiation. The mechanisms by which these initiation factors promote ribosome conformational changes during stages of initiation have been studied using cross-linking, footprinting, site-directed probing, cryo-electron microscopy, X-ray crystallography, fluorescence spectroscopy and single-molecule techniques. Here, we review how the results of these different approaches have begun to converge to yield a detailed molecular understanding of the dynamic motions that the eukaryotic ribosome cycles through during the initiation of protein synthesis.
核糖体是一个动态的机器，在蛋白质合成起始过程中会经历许多构象重排。真细菌和真核生物在蛋白质合成起始过程上存在显著差异。特别是，真核生物蛋白质合成的起始比原核生物起始需要大约一个数量级更多的起始因子来促进有效的mRNA募集和核糖体对起始密码子的识别。利用交联、足迹法、定点探测、冷冻电子显微镜、X射线晶体学、荧光光谱和单分子技术研究了这些起始因子在起始阶段促进核糖体构象变化的机制。在这里，我们综述了这些不同方法的结果如何开始趋同，以对真核核糖体在蛋白质合成起始过程中经历的动态运动产生详细的分子理解。
