RNAs actively cycle on the Sm-like protein Hfq
RNAs actively cycle on the Sm-like protein Hfq
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DOI：
10.1101/gad.591310
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发表时间：
2010-12-01
影响因子：
10.5
通讯作者：
Wagner, E. Gerhart H.
中科院分区：
文献类型：
--
作者：
Fender, Aurelie;Elf, Johan;Wagner, E. Gerhart H.
Hfq是细菌中小RNA（sRNA）介导的调节所需的蛋白质，以低纳摩尔K-d值和长复合物半衰期（>100 min）结合RNA。这与体内调节的1-2分钟响应时间不一致。我们发现，RNA取代彼此在Hfq在很短的时间尺度上的RNA浓度驱动（主动）循环。已经在亚微摩尔浓度的竞争对手RNA，RNA-Hfq复合物的半衰期约为1分钟。我们建议，竞争对手RNA协会瞬时与RNA-Hfq复合物，RNA交换结合位点，和RNA之一最终解离。这解决了“强结合-高转化率”悖论，并允许高效使用Hfq库。
Hfq, a protein required for small RNA (sRNA)-mediated regulation in bacteria, binds RNA with low-nanomolar K-d values and long half-lives of complexes (>100 min). This cannot be reconciled with the 1-2-min response time of regulation in vivo. We show that RNAs displace each other on Hfq on a short time scale by RNA concentration-driven (active) cycling. Already at submicromolar concentrations of competitor RNA, half-lives of RNA-Hfq complexes are approximate to 1 min. We propose that competitor RNA associates transiently with RNA-Hfq complexes, RNAs exchange binding sites, and one of the RNAs eventually dissociates. This solves the "strong binding-high turn-over" paradox and permits efficient use of the Hfq pool.