Binding of small interfering RNA molecules is crucial for RNA interference suppressor activity of rice hoja blanca virus NS3 in plants
Binding of small interfering RNA molecules is crucial for RNA interference suppressor activity of rice hoja blanca virus NS3 in plants
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DOI：
10.1099/vir.0.010488-0
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发表时间：
2009-07-01
影响因子：
3.8
通讯作者：
Schnettler, Esther
中科院分区：
文献类型：
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作者：
Hemmes, Hans;Kaaij, Lucas;Schnettler, Esther
水稻白稻瘟病病毒的NS3蛋白是一种体外隔离小干扰RNA （si）的RNA干扰病毒抑制因子。为了确定这种siRNA结合特性是否是NS3抑制活性的关键决定因素，我们通过丙氨酸点突变改变NS3，并在植物中测试了由此产生的突变蛋白的siRNA结合能力和RNAi抑制活性。在植物中，赖氨酸残基在173-175位的丙氨酸取代导致突变蛋白失去了对sirna的亲和力和RNAi抑制活性。这表明NS3的siRNA结合对于NS3的抑制功能确实是必不可少的，并且位置173-175的残基参与了siRNA结合和抑制活性。
The NS3 protein of rice hoja blanca virus represents a viral suppressor of RNA interference (RNAi) that sequesters small interfering (si)RNAs in vitro. To determine whether this siRNA binding property is the critical determinant for the suppressor activity of NS3, NS3 was altered by alanine point mutations and the resulting mutant proteins were tested for both siRNA binding ability and RNAi suppressor activity in plants. Alanine substitutions of lysine residues at positions 173-175 resulted in mutant proteins that lost both their affinity for siRNAs and their RNAi suppressor activity in planta. This indicates that siRNA binding of NS3 is indeed essential for the suppressor function of NS3 and that residues at positions 173-175 are involved in the siRNA binding and suppressor activities.