Mutations within the decoding site of Escherichia coli 16S rRNA: growth rate impairment, lethality and intragenic suppression.
Mutations within the decoding site of Escherichia coli 16S rRNA: growth rate impairment, lethality and intragenic suppression.
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大肠杆菌 16S rRNA 解码位点内的突变：生长速度受损、致死率和基因内抑制。
DOI：
10.1093/nar/16.16.8129
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发表时间：
1988
影响因子：
14.9
通讯作者：
Zimmermann,RA
中科院分区：
文献类型：
--
作者：
Thomas,CL;Gregory,RJ;Winslow,G;Muto,A;Zimmermann,RA
通过体外诱变，在大肠杆菌16SrRNA中以C1400碱基为中心的保守区引入了几个C→U转换和小的缺失。将突变置于多拷贝质粒上的rrnB操纵子内，在正常rrnB P1P2启动子或来自噬菌体的温度诱导型PL启动子的转录调控下，并引入E. coilhost。当从P1P2启动子表达时，几个突变的16S rRNA损害细胞生长，而其他的，包括其中一个在核糖体解码位点内的1400位的U取代C，对细胞倍增时间几乎没有影响。然而，在1395和1407位的C→U转换，以及C1400的缺失，似乎使它们的宿主失去活性。从AP启动子表达这些突变的细胞在诱导后四代内死亡。出乎意料的是，通过用A、C或U替换01505，致死表型被基因内抑制。抑制可减轻含有U1395、U1407或△C1400突变的30S亚基的功能缺陷。
Several C→U transitions and small deletions were introduced into the conserved region centered on base C1400 in Escherichia coil 16S rRNA byin vitromutagenesis. The mutations were placed withinrrnB operons on multicopy plasmids under the transcriptional regulation of either the normalrrnB P1P2promoters or the temperature-inducible PLpromoter from bacteriophage lain and introduced intoE. coilhosts. When expressed from the P1P2promoters, several of the mutant l6S rRNAs impaired cell growth while others, including one in which U replaced C at position 1400 within the ribosoital decoding site, had little or no effect on cell doubling time. However, C→U transitions at positions 1395 and 1407, as well as the deletion of C1400, appeared to render their hosts inviable. Cells in which these mutations were expressed from the AP promoter died within four generations after induction. Unexpectedly, the lethal phenotype was suppressed intragenically by replacement of 01505 with A, C or U. Suppression may alleviate a functional defect in 30S subunits containing the U1395, U1407 or △C1400 mutations.