A NOVEL RNA MOTIF FOR NEOMYCIN RECOGNITION
A NOVEL RNA MOTIF FOR NEOMYCIN RECOGNITION
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DOI：
10.1016/1074-5521(95)90188-4
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发表时间：
1995-08-01
影响因子：
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通讯作者：
FAMULOK, M
中科院分区：
文献类型：
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作者：
WALLIS, MG;VONAHSEN, U;FAMULOK, M
背景：抗生素可以干扰RNA的活性。氨基糖苷新霉素B抑制原核糖体翻译RNA、I组内含子自剪接、HIV复制和锤头状核酶切割。为探索抗生素等小分子抑制RNA功能的分子基础，我们进行了体外筛选，获得了多种具有识别新霉素能力的RNA分子。结果：所筛选的与新霉素特异结合的RNA分子具有核苷酸同源性。从化学探测和不同克隆之间的协变我们发现，在所有序列中，该区域折叠成发夹结构，足迹和部分碱解实验表明该发夹结构是新霉素结合部位。新霉素的识别具有高亲和力(K-d约为100 nM)和高特异性(对新霉素的亲和力比对帕罗霉素高100倍)。结论：包含共有序列的RNA以及在该区域内显示变异的序列特异性识别新霉素的事实表明，识别新霉素需要一个结构基序而不是特定的核苷酸序列。我们认为，发夹茎环结构基序可能具有加宽的主槽，可能是识别新霉素的先决条件。这种结构模式可以外推到其他天然的新霉素反应RNA。
Background: Antibiotics can interfere with RNA activity. Translation of RNA by the prokaryotic ribosome, self-splicing of group I introns, HIV replication and hammerhead ribozyme cleavage are inhibited by the aminoglycoside neomycin B. To explore the molecular basis by which small molecules such as antibiotics inhibit RNA function, we undertook an in vitro selection to obtain a variety of RNA molecules with the capacity to recognize neomycin.Results: The majority of the RNA molecules selected to specifically bind neomycin share a region of nucleotide sequence homology. From chemical probing and covariations among different clones we show that in all sequences this region folds into a hairpin structure, which from footprinting and partial alkaline hydrolysis experiments is shown to be the neomycin-binding site. Neomycin is recognized with high affinity (K-d approximate to 100 nM) and high specifity (>100-fold higher affinity for neomycin than for paromomycin).Conclusions: The fact that RNAs containing the consensus sequence, as well as sequences that display variations within this region, specifically recognize neomycin suggests that a structural motif rather than a particular nucleotide sequence is required for neomycin recognition. We propose that a hairpin stem-loop structural motif, which might feature a widened major groove, may be a prerequisite for neomycin recognition. This structural pattern can be extrapolated to other natural neomycin-responsive RNAs.