Activation of 2′-5′ oligoadenylate synthetase by single-stranded and double-stranded RNA aptamers
Activation of 2′-5′ oligoadenylate synthetase by single-stranded and double-stranded RNA aptamers
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DOI：
10.1074/jbc.273.6.3236
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发表时间：
1998-02-06
影响因子：
4.8
通讯作者：
Justesen, J
中科院分区：
文献类型：
--
作者：
Hartmann, R;Norby, PL;Justesen, J
已经通过SELEX方法鉴定了许多作为46-kDa形式的人2 ′-5 ′寡腺苷酸合成酶的高亲和力配体的小RNA分子。表面等离子体共振分析表明这些RNA以纳摩尔范围内的解离常数与酶结合，竞争实验表明，2 ′-5 ′寡腺苷酸合成酶分子上的小RNA的结合位点至少部分地与合成的双链腺苷酸合成酶分子上的小RNA的结合位点重叠。链RNA，聚（I）。聚（C）。几种RNA在体外作为2 '-5'寡腺苷酸合成酶的有效激活剂，尽管结合亲和力和激活能力之间没有相关性。具有最强激活潜力的RNA适体似乎具有很少的碱基配对区域。这表明，以前认为仅由双链RNA激活的2 ′-5 ′寡腺苷酸合成酶也可以由几乎没有二级结构的RNA配体激活，因为2 ′-5 ′寡腺苷酸合成酶与其它已知的RNA结合蛋白没有同源性，通过SELEX开发的小的特异性配体将促进RNA-蛋白质相互作用的研究，并可能揭示其结构的新特征-与这种酶有关的功能关系。
A number of small RNA molecules that are high affinity ligands for the 46-kDa form of human 2'-5' oligoadenylate synthetase have been identified by the SELEX method, Surface plasmon resonance analysis indicates that these RNAs bind to the enzyme with dissociation constants in the nanomolar range, Competition experiments indicate that the binding site for the small RNAs on the 2'-5' oligoadenylate synthetase molecule at least partially overlaps that for the synthetic double-stranded RNA, poly(I). poly(C). Several of the RNAs function as potent activators of 2'-5' oligoadenylate synthetase in vitro, although there is no correlation between binding affinity and ability to activate, The RNA aptamers having the strongest activation potential appear to have few base-paired regions. This suggests that 2'-5' oligoadenylate synthetase, which has previously been believed to be activated only by double-stranded RNA, can also be activated by RNA ligands with little secondary structure, Since 2'-5' oligoadenylate synthetase possesses no homology to other known RNA-binding proteins, the development of small specific ligands by SELEX should facilitate studies of RNA-protein interactions and may reveal novel features of the structure-function relationships involving this enzyme.