Studies on the function of two adjacent N6,N6-dimethyladenosines near the 3' end of 16 S ribosomal RNA of Escherichia coli. II. The effect of the absence of the methyl groups on initiation of protein biosynthesis.
Studies on the function of two adjacent N6,N6-dimethyladenosines near the 3' end of 16 S ribosomal RNA of Escherichia coli. II. The effect of the absence of the methyl groups on initiation of protein biosynthesis.
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大肠杆菌16S核糖体RNA 3端附近两个相邻N6,N6-二甲基腺苷的功能研究。
DOI：
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发表时间：
1979
影响因子：
4.8
通讯作者：
P. van Knippenberg
中科院分区：
文献类型：
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作者：
B. Poldermans;C. V. van Buul;P. van Knippenberg
用野生型（甲基化）和抗春雷霉素（非甲基化）大肠杆菌研究了大肠杆菌16 SrTNA 3'端附近两个相邻腺苷的N6原子上甲基存在与否对蛋白质生物合成起始的影响。大肠杆菌核糖体（参见前面的论文（Poldermans，B.，Goosen，N.，和货车Knippenberg，P. H.（1979）J.Biol.Chem.254，9085- 9089））。野生型和突变型核糖体的pH、温度和离子强度条件是相同的，在这些条件下，fMet-tRNA与核糖体的结合最大化。Mg 2+和因子依赖性的核糖体解离以及亚基的缔合对于甲基化和未甲基化的核糖体也是相同的。fMet-tRNA与野生型和突变型70 S核糖体的结合需要相同量的三种起始因子。然而，最佳的fMet-tRNA结合到未甲基化的30 S核糖体需要更多的起始因子3比结合到甲基化的30 S核糖体，前提是起始因子1不存在。当使用来自野生型菌株的纯化甲基化酶和甲基供体S-腺苷甲硫氨酸甲基化突变体30 S核糖体时，这种差异完全消除。
The effect of the presence or absence of methyl groups on the N6 atoms of two adjacent adenosines near the 3' end of 16 S rTNA of Escherichia coli on initiation of protein biosynthesis has been studied using wild type (methylated) and kasugamycin-resistant (unmethylated) E. coli ribosomes (see preceding paper (Poldermans, B., Goosen, N., and Van Knippenberg, P. H. (1979) J. Biol. Chem. 254, 9085--9089)). Conditions of pH, temperature, and ionic strength at which binding of fMet-tRNA to ribosomes proceeds maximally are the same for wild type and mutant ribosomes. Mg2+- and factor-dependent dissociation of ribosomes as well as the association of the subunits is also the same for methylated and unmethylated ribosomes. Binding of fMet-tRNA to wild type and to mutant 70 S ribosomes requires the same amount of the three initiation factors. However, optimal fMet-tRNA binding to unmethylated 30 S ribosomes needs more of initiation factor 3 than does binding to methylated 30 S ribosomes, provided that initiation factor 1 is absent. This difference is completely abolished when mutant 30 S ribosomes are methylated using purified methylase from the wild type strain and the methyl donor S-adenosylmethionine.