Gottesman S, McCullen C A, Guillier M, Vanderpool C K, Majdalani N, Benhammou J, Thompson K M, FitzGerald P C, Sowa N A, FitzGerald D J
Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892, USA.
Cold Spring Harb Symp Quant Biol. 2006;71:1-11. doi: 10.1101/sqb.2006.71.016.
Recent studies have uncovered dozens of regulatory small RNAs in bacteria. A large number of these small RNAs act by pairing to their target mRNAs. The outcome of pairing can be either stimulation or inhibition of translation. Pairing in vivo frequently depends on the RNA-binding protein Hfq. Synthesis of these small RNAs is tightly regulated at the level of transcription; many of the well-studied stress response regulons have now been found to include a regulatory RNA. Expression of the small RNA can help the cell cope with environmental stress by redirecting cellular metabolism, exemplified by RyhB, a small RNA expressed upon iron starvation. Although small RNAs found in Escherichia coli can usually be identified by sequence comparison to closely related enterobacteria, other approaches are necessary to find the equivalent RNAs in other bacterial species. Nonetheless, it is becoming increasingly clear that many if not all bacteria encode significant numbers of these important regulators. Tracing their evolution through bacterial genomes remains a challenge.
最近的研究在细菌中发现了几十种调控性小RNA。其中大量的小RNA通过与它们的靶标mRNA配对发挥作用。配对的结果可以是刺激或抑制翻译。体内配对通常依赖于RNA结合蛋白Hfq。这些小RNA的合成在转录水平受到严格调控;现在发现许多经过充分研究的应激反应调节子都包含一种调控RNA。小RNA的表达可以通过重定向细胞代谢帮助细胞应对环境应激,以铁饥饿时表达的小RNA RyhB为例。虽然在大肠杆菌中发现的小RNA通常可以通过与密切相关的肠道细菌进行序列比较来鉴定,但在其他细菌物种中找到等效的RNA则需要其他方法。尽管如此,越来越清楚的是,许多(如果不是所有的话)细菌都编码大量这些重要的调节子。通过细菌基因组追踪它们的进化仍然是一个挑战。