RNase G complementation of rne null mutation identifies functional interrelationships with RNase E in Escherichia coli
RNase G complementation of rne null mutation identifies functional interrelationships with RNase E in Escherichia coli
复制标题
DOI：
10.1046/j.1365-2958.2002.02848.x
复制
发表时间：
2002-03-01
影响因子：
3.6
通讯作者：
Cohen, SN
中科院分区：
文献类型：
--
作者：
Lee, K;Bernstein, JA;Cohen, SN
大肠杆菌核糖核酸内切酶RNase E （Rne）和RNase G （Rng）具有序列相似性和广泛相似的序列特异性。虽然缺乏Rne通常是致命的，但我们在这里表明，缺乏Rne基因的大肠杆菌可以通过过度表达Rng而存活。RNA补充细胞积累了5S核糖体RNA （rRNA）和RNase P的RNA成分（即M1 RNA）的前体，表明RNase G没有恢复这些rne切割RNA的正常加工；此外，体外RNase G切割前体不能产生5S rRNA和M1 RNA。利用含有4405个大肠杆菌开放阅读框（orf）的DNA微阵列，我们鉴定出稳态水平受Rne、Rng或RNase E的n端催化结构域影响的mrna。在Rng补充的Rne缺失突变体中，受RNase E缺乏影响的大多数转录物种类也有所增加。然而，在rne缺陷细胞中积累的大约100个mrna通过环互补而减少，从而确定了其加工或降解可能是RNase E必要性基础的靶标。在这一组中，显著突出的是与能量产生途径或大分子合成或降解有关的mrna。
The Escherichia coli endoribonucleases RNase E (Rne) and RNase G (Rng) have sequence similarity and broadly similar sequence specificity. Whereas the absence of Rne normally is lethal, we show here that E. coli bacteria that lack the rne gene can be made viable by overexpression of Rng. Rng-complemented cells accumulated precursors of 5S ribosomal RNA (rRNA) and the RNA component of RNase P (i.e. M1 RNA), indicating that normal processing of these Rne-cleaved RNAs was not restored by RNase G; additionally, neither 5S rRNA nor M1 RNA was generated from precursors by RNase G cleavage in vitro. Using DNA microarrays containing 4405 Escherichia coli open reading frames (ORFs), we identified mRNAs whose steady-state level was affected by Rne, Rng or the N-terminal catalytic domain of RNase E. Most transcript species affected by RNase E deficiency were also elevated in an rne deletion mutant complemented by Rng. However, approximately 100 mRNAs that accumulated in Rne-deficient cells were decreased by rng-complemention, thus identifying targets whose processing or degradation may be the basis for RNase E essentiality. Remarkably prominent in this group were mRNAs implicated in energy-generating pathways or in the synthesis or degradation of macromolecules.