Intrinsic disorder in Viral Proteins Genome-Linked: experimental and predictive analyses.
Intrinsic disorder in Viral Proteins Genome-Linked: experimental and predictive analyses.
复制标题
DOI：
10.1186/1743-422x-6-23
复制
发表时间：
2009-02-16
期刊：
影响因子：
4.8
通讯作者：
Fargette D
中科院分区：
文献类型：
--
作者：
Hébrard E;Bessin Y;Michon T;Longhi S;Uversky VN;Delalande F;Van Dorsselaer A;Romero P;Walter J;Declerck N;Fargette D
VPG是与某些病毒基因组的5‘端相连的病毒蛋白。几种VPG与真核翻译起始因子eIF4E之间的相互作用在植物侵染过程中起着关键作用。然而，VPgs并不局限于植物病毒，还参与了几种动物病毒的基因组复制和蛋白质翻译。到目前为止，结构数据仍然局限于小核糖核酸病毒VPG。最近，三种植物病毒VPgs被证明是天然的未折叠蛋白。本文报道了水稻黄斑病毒(RYMV，SobemoVirus)和生菜花叶病毒(LMV，PotyVirus)两种植物病毒VPgs的细菌表达、纯化和生化特性。利用远紫外圆二色谱和尺寸排除层析法，我们证明了RYMV和LMV VPgs在溶液中分别是主要或部分非结构的。使用几个无序预测因子，我们发现这两种蛋白质都被预测具有无序区域。接下来，我们将这些结果扩展到代表病毒多样性的14个VPG。在所有的VPG序列中都预测到了无序区，无论是属还是科。基于这些结果，我们提出内禀无序是VPG的一个共同特征。根据VPgs的生物学作用，讨论了内源性紊乱的功能作用。
VPgs are viral proteins linked to the 5' end of some viral genomes. Interactions between several VPgs and eukaryotic translation initiation factors eIF4Es are critical for plant infection. However, VPgs are not restricted to phytoviruses, being also involved in genome replication and protein translation of several animal viruses. To date, structural data are still limited to small picornaviral VPgs. Recently three phytoviral VPgs were shown to be natively unfolded proteins. In this paper, we report the bacterial expression, purification and biochemical characterization of two phytoviral VPgs, namely the VPgs of Rice yellow mottle virus (RYMV, genus Sobemovirus) and Lettuce mosaic virus (LMV, genus Potyvirus). Using far-UV circular dichroism and size exclusion chromatography, we show that RYMV and LMV VPgs are predominantly or partly unstructured in solution, respectively. Using several disorder predictors, we show that both proteins are predicted to possess disordered regions. We next extend theses results to 14 VPgs representative of the viral diversity. Disordered regions were predicted in all VPg sequences whatever the genus and the family. Based on these results, we propose that intrinsic disorder is a common feature of VPgs. The functional role of intrinsic disorder is discussed in light of the biological roles of VPgs.