Reprogramming of anaerobic metabolism by the FnrS small RNA
Reprogramming of anaerobic metabolism by the FnrS small RNA
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DOI：
10.1111/j.1365-2958.2010.07044.x
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发表时间：
2010-03-01
影响因子：
3.6
通讯作者：
Storz, Gisela
中科院分区：
文献类型：
--
作者：
Durand, Sylvain;Storz, Gisela
小RNA（sRNA）通过与反式编码的mRNA进行碱基配对来调节代谢，以响应各种环境刺激。在这里，我们描述了一个Hfq结合的sRNA（FnrS），其表达诱导后，从有氧到厌氧条件的转变，并起到下调各种mRNA编码代谢酶的水平。基本培养基中的厌氧诱导强烈依赖于FNR，但也受到ArcA和CRP转录调节因子的影响。全基因组表达分析显示，至少32种mRNA的水平在FnrS过表达时下调，其中15种通过TargetRNA预测与FnrS碱基配对。在许多肠杆菌中，sRNA在其整个长度上高度保守，突变分析显示FnrS的两个独立区域与不同的靶mRNA配对。大多数靶基因先前被报道以FNR依赖性方式下调，但缺乏可识别的FNR结合位点。因此，我们认为，FnrS延长FNR调节子，并通过抑制在这些条件下不需要的酶的合成来提高厌氧代谢的效率。
P>Small RNAs (sRNAs) that act by base pairing with trans-encoded mRNAs modulate metabolism in response to a variety of environmental stimuli. Here, we describe an Hfq-binding sRNA (FnrS) whose expression is induced upon a shift from aerobic to anaerobic conditions and which acts to downregulate the levels of a variety of mRNAs encoding metabolic enzymes. Anaerobic induction in minimal medium depends strongly on FNR but is also affected by the ArcA and CRP transcription regulators. Whole genome expression analysis showed that the levels of at least 32 mRNAs are downregulated upon FnrS overexpression, 15 of which are predicted to base pair with FnrS by TargetRNA. The sRNA is highly conserved across its entire length in numerous Enterobacteria, and mutational analysis revealed that two separate regions of FnrS base pair with different sets of target mRNAs. The majority of the target genes were previously reported to be downregulated in an FNR-dependent manner but lack recognizable FNR binding sites. We thus suggest that FnrS extends the FNR regulon and increases the efficiency of anaerobic metabolism by repressing the synthesis of enzymes that are not needed under these conditions.