The RNA-binding protein Hfq is important for ribosome biogenesis and affects translation fidelity
The RNA-binding protein Hfq is important for ribosome biogenesis and affects translation fidelity
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DOI：
10.15252/embj.201797631
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发表时间：
2018-06-01
期刊：
影响因子：
11.4
通讯作者：
Arraiano, Cecilia M.
中科院分区：
文献类型：
--
作者：
Andrade, Jose M.;dos Santos, Ricardo F.;Arraiano, Cecilia M.
核糖体的生物发生是一个涉及多个因素的复杂过程。在这里，我们证明了广泛保守的RNA伴侣Hfq，它可以调节sRNA-mRNA的碱基对，在大肠杆菌中的rRNA加工和核糖体组装中起着关键作用。Hfq与17S rRNA前体结合，促进其正确加工和折叠为成熟的16S rRNA。HFQ协助核糖体组装，并与30S前颗粒结合，但不与成熟的30S亚基结合。Hfq的失活显著减少了成熟70年代核糖体的数量。核糖体水平的降低取决于位于HfQ远侧表面的残基，而不是控制与sRNAs相互作用的近端和边缘表面的残基。我们的结果表明，Hfq介导的核糖体调节不依赖于其作为sRNA调节因子的功能。此外，我们观察到Hfq的失活影响了翻译效率和保真度，这两个特征都是异常组装的核糖体的特征。我们的工作扩展了类Sm蛋白Hfq的功能，超越了其在小RNA介导的调节中的功能，并揭示了Hfq在核糖体生物发生和翻译中的一个新的角色。
Ribosome biogenesis is a complex process involving multiple factors. Here, we show that the widely conserved RNA chaperone Hfq, which can regulate sRNA-mRNA basepairing, plays a critical role in rRNA processing and ribosome assembly in Escherichia coli. Hfq binds the 17S rRNA precursor and facilitates its correct processing and folding to mature 16S rRNA. Hfq assists ribosome assembly and associates with pre-30S particles but not with mature 30S subunits. Inactivation of Hfq strikingly decreases the pool of mature 70S ribosomes. The reduction in ribosome levels depends on residues located in the distal face of Hfq but not on residues found in the proximal and rim surfaces which govern interactions with the sRNAs. Our results indicate that Hfq-mediated regulation of ribosomes is independent of its function as sRNA-regulator. Furthermore, we observed that inactivation of Hfq compromises translation efficiency and fidelity, both features of aberrantly assembled ribosomes. Our work expands the functions of the Sm-like protein Hfq beyond its function in small RNA-mediated regulation and unveils a novel role of Hfq as crucial in ribosome biogenesis and translation.