Allosteric collaboration between elongation factor G and the ribosomal L1 stalk directs tRNA movements during translation
Allosteric collaboration between elongation factor G and the ribosomal L1 stalk directs tRNA movements during translation
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DOI：
10.1073/pnas.0908077106
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发表时间：
2009-09-15
影响因子：
11.1
通讯作者：
Gonzalez, Ruben L., Jr.
中科院分区：
文献类型：
--
作者：
Fei, Jingyi;Bronson, Jonathan E.;Gonzalez, Ruben L., Jr.
确定tRNA在翻译过程中快速精确地通过核糖体A、P和E位点的机制仍然是蛋白质合成研究的主要目标。在这里，我们报告的实时动态L1柄，一个结构元件的核糖体大亚基，涉及在翻译过程中指导tRNA运动。在易位前核糖体复合物中，L1柄存在于开放和封闭构象之间的动态平衡中。延伸因子G（EF-G）的结合通过至少两种不同的动力学机制之一将这种平衡向闭合构象转移，其中P-位点tRNA的身份决定了所采取的动力学途径。在posttranslocation复合物，L1柄动力学依赖于E-位点tRNA的存在和身份。总的来说，我们的数据表明，EF-G和L1柄变构合作，直接从P到E站点的tRNA易位，并建议一个模型的E-站点tRNA的释放。
Determining the mechanism by which tRNAs rapidly and precisely transit through the ribosomal A, P, and E sites during translation remains a major goal in the study of protein synthesis. Here, we report the real-time dynamics of the L1 stalk, a structural element of the large ribosomal subunit that is implicated in directing tRNA movements during translation. Within pretranslocation ribosomal complexes, the L1 stalk exists in a dynamic equilibrium between open and closed conformations. Binding of elongation factor G (EF-G) shifts this equilibrium toward the closed conformation through one of at least two distinct kinetic mechanisms, where the identity of the P-site tRNA dictates the kinetic route that is taken. Within posttranslocation complexes, L1 stalk dynamics are dependent on the presence and identity of the E-site tRNA. Collectively, our data demonstrate that EF-G and the L1 stalk allosterically collaborate to direct tRNA translocation from the P to the E sites, and suggest a model for the release of E-site tRNA.