Interplay of methionine tRNAs with translation elongation factor Tu and translation initiation factor 2 in Escherichia coli
Interplay of methionine tRNAs with translation elongation factor Tu and translation initiation factor 2 in Escherichia coli
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DOI：
10.1074/jbc.271.37.22321
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发表时间：
1996-09-13
影响因子：
4.8
通讯作者：
Blanquet, S
中科院分区：
文献类型：
--
作者：
Guillon, JM;Heiss, S;Blanquet, S
根据它们在翻译中的作用，trna特异性地与延伸因子Tu （EFTu）或起始因子2 （IF2）相互作用。我们在此描述了过量产生EFTu和IF2对体内各种突变tRNA（Met）物种的延长子和启动子活性的影响。获得的数据表明，通过一种或另一种翻译途径选择tRNA取决于翻译因子的相对数量。适度过度表达EFTu足以导致在延伸过程中误用启动tRNA，而过度表达IF2则允许在未甲酰化的tRNA物种中启动翻译。此外，我们报道了缺乏甲酰化酶活性的菌株可以通过过量生产tRNA(f)（Met）来治愈。本研究为甲酰化在定义tRNA(f)（Met）引发剂身份中的重要性提供了额外的证据，也为缺乏功能性甲酰化酶基因的细菌菌株的残留生长提供了可能的解释，如Guillon， J. M., Mechulam， Y., Schmitter， J.-M.所观察到的。（1992） .微生物学与微生物学杂志（英文版）。
According to their role in translation, tRNAs specifically interact either with elongation factor Tu (EFTu) or with initiation factor 2 (IF2). We here describe the effects of overproducing EFTu and IF2 on the elongator versus initiator activities of various mutant tRNA(Met) species in vivo, The data obtained indicate that the selection of a tRNA through one or the other pathway of translation depends on the relative amounts of the translational factors. A moderate overexpression of EFTu is enough to lead to a misappropriation of initiator tRNA in the elongation process, whereas overproduced IF2 allows the initiation of translation to occur with unformylated tRNA species. In addition, we report that a strain devoid of formylase activity can be cured by the overproduction of tRNA(f)(Met). The present study brings additional evidence for the importance of formylation in defining tRNA(f)(Met) initiator identity, as well as a possible explanation for the residual growth of bacterial strains lacking a functional formylase gene such as observed in Guillon, J. M., Mechulam, Y., Schmitter, J.-M., Blanquet, S., and Fayat, G. (1992) J. Bacteriol. 174, 4294-4301.