Thiostrepton inhibition of tRNA delivery to the ribosome
Thiostrepton inhibition of tRNA delivery to the ribosome
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DOI：
10.1261/rna.499407
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发表时间：
2007-12-01
期刊：
影响因子：
4.5
通讯作者：
Puglisi, Joseph D.
中科院分区：
文献类型：
--
作者：
Gonzalez, Ruben L., Jr.;Chu, Steven;Puglisi, Joseph D.
核糖体刺激的鸟苷-5 '-三磷酸（GTP）通过鸟苷三磷酸酶（GTdR）翻译因子的水解驱动核糖体的蛋白质合成。在核糖体GTP酶中心的GTP水解被延伸因子Tu（EF-Tu）变构偶联到核糖体解码位点的信使RNA（mRNA）密码子：氨酰基转移RNA（aa-tRNA）反密码子识别对于准确和快速的aa-tRNA选择是必不可少的。在这里，我们使用单分子的方法来研究抗生素thiostrepton的作用机制，并表明，在aa-tRNA选择过程中，核糖体的GTP酶中心至少有两个独立的功能：EF-Tu（GTP）的结合和GTP水解的刺激因子。我们将这两种功能的GTdR中心，并分配到不同的，保守的结构区域的核糖体。这些数据提供了一个特定的模型之间的耦合解码网站和GTdR中心在aa-tRNA的选择，以及一个一般的核糖体刺激的GTP水解的GTdR翻译因子的机械模型。
Ribosome-stimulated hydrolysis of guanosine-5'-triphosphate (GTP) by guanosine triphosphatase (GTPase) translation factors drives protein synthesis by the ribosome. Allosteric coupling of GTP hydrolysis by elongation factor Tu (EF-Tu) at the ribosomal GTPase center to messenger RNA (mRNA) codon:aminoacyl-transfer RNA (aa-tRNA) anticodon recognition at the ribosomal decoding site is essential for accurate and rapid aa-tRNA selection. Here we use single-molecule methods to investigate the mechanism of action of the antibiotic thiostrepton and show that the GTPase center of the ribosome has at least two discrete functions during aa-tRNA selection: binding of EF-Tu(GTP) and stimulation of GTP hydrolysis by the factor. We separate these two functions of the GTPase center and assign each to distinct, conserved structural regions of the ribosome. The data provide a specific model for the coupling between the decoding site and the GTPase center during aa-tRNA selection as well as a general mechanistic model for ribosome-stimulated GTP hydrolysis by GTPase translation factors.