FinO is an RNA chaperone that facilitates sense-antisense RNA interactions
FinO is an RNA chaperone that facilitates sense-antisense RNA interactions
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DOI：
10.1093/emboj/cdg607
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发表时间：
2003-12-01
期刊：
影响因子：
11.4
通讯作者：
Glover, JNM
中科院分区：
文献类型：
--
作者：
Arthur, DC;Ghetu, AF;Glover, JNM
FinO蛋白通过促进主要F质粒转录激活因子TraJ的mRNA和反义RNA FinP之间的相互作用来抑制F质粒接合转移。已知FinO结合FinP和traJ RNA中的茎环结构;然而，FinO促进有义-反义配对的机制知之甚少。在这里，我们表明，FinO作为一个RNA分子伴侣，以促进链交换和最小的RNA目标之间的双链来自FinP。这强烈地表明，FinO可以起到使FinP和traJ RNA内的内部二级结构不稳定的作用，否则这些二级结构将充当有义-反义配对的动力学陷阱。FinO催化的碱基对不稳定的能量不产生ATP水解，但似乎是直接从FinO RNA结合自由能提供。链交换特异性缺陷但不具有RNA结合活性的突变体的活性分析表明，链交换对于FinO介导有义-反义RNA识别的能力是必不可少的，并且这种功能在体内抑制缀合中也起作用。
The protein FinO represses F-plasmid conjugative transfer by facilitating interactions between the mRNA of the major F-plasmid transcriptional activator, TraJ, and an antisense RNA, FinP. FinO is known to bind stem-loop structures in both FinP and traJ RNAs; however, the mechanism by which FinO facilitates sense-antisense pairing is poorly understood. Here we show that FinO acts as an RNA chaperone to promote strand exchange and duplexing between minimal RNA targets derived from FinP. This strongly suggests that FinO may function to destabilize internal secondary structures within FinP and traJ RNAs that would otherwise act as a kinetic trap to sense-antisense pairing. The energy for FinO-catalyzed base-pair destabilization does not arise from ATP hydrolysis but appears to be supplied directly from FinO RNA binding free energy. An analysis of the activities of mutants that are specifically deficient in strand exchange but not RNA-binding activity demonstrates that strand exchange is essential to the ability of FinO to mediate sense-antisense RNA recognition, and that this function also plays a role in repression of conjugation in vivo.