Genetic and comparative analyses reveal an alternative secondary structure in the region of nt 912 of Escherichia coli 16S rRNA.
Genetic and comparative analyses reveal an alternative secondary structure in the region of nt 912 of Escherichia coli 16S rRNA.
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遗传和比较分析揭示了大肠杆菌 16S rRNA nt 912 区域的替代二级结构。
DOI：
10.1073/pnas.92.23.10555
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发表时间：
1995
影响因子：
11.1
通讯作者：
Dahlberg,AE
中科院分区：
文献类型：
--
作者：
Lodmell,JS;Gutell,RR;Dahlberg,AE
大肠埃希菌16S rRNA 912位突变导致两种显著的表型。C-->；U转换使人对链霉素产生抗药性，而C-->；G转换则导致细胞生长速度显著减慢。从生长缓慢的G912突变体开始，使用随机突变法分离出第二个位点突变，该突变使生长恢复到接近野生型的速度。第二个突变为16S rRNA 885位的G-->；C颠换。含有G912突变的细胞倍增时间延长，蔗糖梯度核糖体/亚单位谱异常，对壮观霉素的敏感性增加，在壮观霉素存在下依赖链霉素生长，转化率降低，而G912/C885双突变的细胞在这些检测中与野生型相似。比较分析表明，912位和885位之间存在显著的协变。因此，第二位点抑制分析、功能分析和比较数据表明，NT 912和NT 885之间的相互作用是保守的，是正常核糖体功能所必需的。此外，比较数据表明，相互作用扩展到包括G885-G886-G887与C912-U911-C910配对。提出了16S rRNA中心结构域的另一种二级结构元。
Mutations at position 912 of Escherichia coli 16S rRNA result in two notable phenotypes. The C-->U transition confers resistance to streptomycin, a translational-error-inducing antibiotic, while a C-->G transversion causes marked retardation of cell growth rate. Starting with the slow-growing G912 mutant, random mutagenesis was used to isolate a second site mutation that restored growth nearly to the wild-type rate. The second site mutation was identified as a G-->C transversion at position 885 in 16S rRNA. Cells containing the G912 mutation had an increased doubling time, abnormal sucrose gradient ribosome/subunit profile, increased sensitivity to spectinomycin, dependence upon streptomycin for growth in the presence of spectinomycin, and slower translation rate, whereas cells with the G912/C885 double mutation were similar to wild type in these assays. Comparative analysis showed there was significant covariation between positions 912 and 885. Thus the second-site suppressor analysis, the functional assays, and the comparative data suggest that the interaction between nt 912 and nt 885 is conserved and necessary for normal ribosome function. Furthermore, the comparative data suggest that the interaction extends to include G885-G886-G887 pairing with C912-U911-C910. An alternative secondary structure element for the central domain of 16S rRNA is proposed.