A functional interaction between ribosomal proteins S7 and S11 within the bacterial ribosome
A functional interaction between ribosomal proteins S7 and S11 within the bacterial ribosome
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DOI：
10.1074/jbc.m306534200
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发表时间：
2003-11-07
影响因子：
4.8
通讯作者：
Brakier-Gingras, L
中科院分区：
文献类型：
--
作者：
Robert, F;Brakier-Gingras, L
在这项研究中，我们使用定点突变来破坏细菌30 S亚基晶体结构中核糖体蛋白S7和S11之间的相互作用。这种相互作用位于E位点，将30个S亚基的头部连接到平台上，并参与形成出口通道，通过该通道传递30个S结合的信使RNA。无论是S7的突变还是S11的突变都不能阻止蛋白质整合到S的30个亚基中，但它们扰乱了核糖体的功能。体内分析表明，S7或S11突变的核糖体在控制翻译保真度方面发生了变化，具有更强的移码、阅读无义密码子和密码子误读的能力。脚印和滤膜结合分析表明，30个S7或S11突变的S亚基与mR NA的结合能力增强。S7和S11突变的影响可能与30个S的头部的灵活性增加、mR NA出口通道的开放以及A和E位点之间拟议的变构耦合的扰动有关。综上所述，我们的结果表明S7和S11以功能方式相互作用，并支持蛋白质-蛋白质相互作用有助于核糖体动态的概念。
In this study, we used site-directed mutagenesis to disrupt an interaction that had been detected between ribosomal proteins S7 and S11 in the crystal structure of the bacterial 30 S subunit. This interaction, which is located in the E site, connects the head of the 30 S subunit to the platform and is involved in the formation of the exit channel through which passes the 30 S-bound messenger RNA. Neither mutations in S7 nor mutations in S11 prevented the incorporation of the proteins into the 30 S subunits but they perturbed the function of the ribosome. In vivo assays showed that ribosomes with either mutated S7 or S11 were altered in the control of translational fidelity, having an increased capacity for frameshifting, readthrough of a nonsense codon and codon misreading. Toeprinting and filter-binding assays showed that 30 S subunits with either mutated S7 or S11 have an enhanced capacity to bind mRNA. The effects of the S7 and S11 mutations can be related to an increased flexibility of the head of the 30 S, to an opening of the mRNA exit channel and to a perturbation of the proposed allosteric coupling between the A and E sites. Altogether, our results demonstrate that S7 and S11 interact in a functional manner and support the notion that protein-protein interactions contribute to the dynamics of the ribosome.