NMR structure of stem-loop D from human rhinovirus-14
NMR structure of stem-loop D from human rhinovirus-14
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DOI：
10.1261/rna.313707
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发表时间：
2007-03-01
期刊：
影响因子：
4.5
通讯作者：
Pascal, Steven M.
中科院分区：
文献类型：
--
作者：
Headey, Stephen J.;Huang, He;Pascal, Steven M.
小核糖核酸病毒RNA基因组的5'-三叶草对于核糖核蛋白复制复合体的组装是必不可少的。三叶草茎环D （SLD）是多功能病毒蛋白3C（pro）的识别位点。该蛋白是主要的病毒蛋白酶，它与SLD的相互作用也有助于定位病毒RNA依赖的RNA聚合酶（3D(pol)）进行复制。人鼻病毒-14 （HRV-14）与大多数小核糖核酸病毒不同，其SLD形成cUAUg三环，而不是更常见的uYACGg四环。这种差异在功能上似乎是显著的，因为来自含四爪虫病毒的3C（pro）不能结合HRV-14 SLD。我们用核磁共振光谱法确定了HRV-14 SLD的溶液结构。结构以a型螺旋为主，但具有中心嘧啶-嘧啶碱基配对区和明显加宽的主槽。在uYACGg四环中存在的稳定氢键在cUAUg三环中没有发现。然而，三联环使用不同的结构元素来呈现大致相似的表面：序列和底层架构不保守，但表面结构的关键方面是保守的。然而，重要的结构差异确实存在，这可能解释了3C（pro）和SLD之间观察到的交叉同型结合特异性。
The 5'-cloverleaf of the picornavirus RNA genome is essential for the assembly of a ribonucleoprotein replication complex. Stem-loop D (SLD) of the cloverleaf is the recognition site for the multifunctional viral protein 3C(pro). This protein is the principal viral protease, and its interaction with SLD also helps to position the viral RNA-dependent RNA polymerase (3D(pol)) for replication. Human rhinovirus-14 (HRV-14) is distinct from the majority of picornaviruses in that its SLD forms a cUAUg triloop instead of the more common uYACGg tetraloop. This difference appears to be functionally significant, as 3C(pro) from tetraloop-containing viruses cannot bind the HRV-14 SLD. We have determined the solution structure of the HRV-14 SLD using NMR spectroscopy. The structure is predominantly an A-form helix, but with a central pyrimidine-pyrimidine base-paired region and a significantly widened major groove. The stabilizing hydrogen bonding present in the uYACGg tetraloop was not found in the cUAUg triloop. However, the triloop uses different structural elements to present a largely similar surface: sequence and underlying architecture are not conserved, but key aspects of the surface structure are. Important structural differences do exist, though, and may account for the observed cross-isotype binding specificities between 3C(pro) and SLD.