IDENTIFICATION OF 2 NOVEL ARGININE BINDING DNAS
IDENTIFICATION OF 2 NOVEL ARGININE BINDING DNAS
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DOI：
10.1002/j.1460-2075.1995.tb00268.x
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发表时间：
1995-12-01
期刊：
影响因子：
11.4
通讯作者：
FRANKEL, AD
中科院分区：
文献类型：
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作者：
HARADA, K;FRANKEL, AD
已知RNA三级结构在RNA-蛋白质识别和RNA功能中起关键作用。为了研究DNA三级结构如何与RNA结构相关，我们进行了体外选择实验以鉴定特异性结合精氨酸的单链DNA，并将结果与用RNA进行的类似实验进行比较。通常发现与人免疫缺陷病毒TAR RNA中的精氨酸结合位点相关的蛾，而在DNA的情况下，发现两个新的基序，没有发现TAR样结构。一个DNA基序，在40%的克隆序列中发现，形成具有高度保守的10个核苷酸环的发夹结构，而第二蛾特别富含G残基。化学干扰和诱变实验确定了两种蛾中形成特异性精氨酸结合位点的核苷酸，硫酸二甲酯足迹实验确定了两种蛾中在精氨酸存在下被保护免于甲基化的单个鸟嘌呤残基，这表明可能的精氨酸接触位点或DNA中的构象变化，圆二色性实验表明，这两种DNA在精氨酸结合时发生构象变化，并且精氨酸胍基团单独负责结合，提出了一种富含G基序的模型，其中鸟嘌呤和腺嘌呤四联体的混合可能形成一种新的DNA结构，精氨酸结合的DNA和RNA将为研究核酸三级结构提供有用的模型系统。
RNA tertiary structure is known to play critical roles in RNA-protein recognition and RNA function, To examine how DNA tertiary structure might relate to RNA structure, we performed in vitro selection experiments to identify single-stranded DNAs that specifically bind arginine, and compared the results with analogous experiments performed with RNA, In the case of RNA, a moth related to the arginine binding site in human immunodeficiency virus TAR RNA was commonly found, whereas in the case of DNA, two novel motifs and no TAR-like structures were found, One DNA motif, found in similar to 40% of the cloned sequences, forms a hairpin structure with a highly conserved 10 nucleotide loop, whereas the second moth is especially rich in G residues. Chemical interference and mutagenesis experiments identified nucleotides in both moths that form specific arginine binding sites, and dimethylsulfate footprinting experiments identified single guanine residues in both that are protected from methylation in the presence of arginine, suggesting possible sites of arginine contact or conformational changes in the DNAs, Circular dichroism experiments indicated that both DNAs undergo conformational changes upon arginine binding and that the arginine guanidinium group alone is responsible for binding, A model for the G-rich motif is proposed in which mixed guanine and adenine quartets may form a novel DNA structure, Arginine binding DNAs and RNAs should provide useful model systems for studying nucleic acid tertiary structure.