Protein displacement by DExH/D "RNA helicases" without duplex unwinding
Protein displacement by DExH/D "RNA helicases" without duplex unwinding
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DOI：
10.1126/science.1095596
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发表时间：
2004-04-30
期刊：
影响因子：
56.9
通讯作者：
Jankowsky, E
中科院分区：
文献类型：
--
作者：
Fairman, ME;Maroney, PA;Jankowsky, E
DExH/D超家族成员对RNA代谢的几乎所有方面都是必不可少的，包括前信使RNA剪接、RNA干扰、翻译和核质运输。这些酶的生理底物被认为是双链RNA区域，因为几种DExH/D蛋白在体外催化链分离。这些“RNA解旋酶”也可以破坏RNA-蛋白质的相互作用，但目前还不清楚这种活动是否与双链解离有关。在这里，我们证明了两个不相关的DExH/D蛋白催化蛋白质置换不依赖于双链解离。因此，DExH/D蛋白的基本功能并不局限于RNA双链，而是可以在广泛的核糖核蛋白底物上发挥作用。
Members of the DExH/D superfamily of nucleic acid-activated nucleotide triphosphatases are essential for virtually all aspects of RNA metabolism, including pre-messenger RNA splicing, RNA interference, translation, and nucleocytoplasmic trafficking. Physiological substrates for these enzymes are thought to be regions of double-stranded RNA, because several DExH/D proteins catalyze strand separation in vitro. These "RNA helicases" can also disrupt RNA-protein interactions, but it is unclear whether this activity is coupled to duplex unwinding. Here we demonstrate that two unrelated DExH/D proteins catalyze protein displacement independently of duplex unwinding. Therefore, the essential functions of DExH/D proteins are not confined to RNA duplexes but can be exerted on a wide range of ribonucleoprotein substrates.