S1 is 4501 bp in length and codes for a 168 kDa protein, which is predicted to be a RNA-dependent RNA polymerase (RdRp), because it contains the characteristic motif of GDD (Glycine-Aspartate-Aspartate) and other conserved domains.

• 其中S1全长4501bp，编码约168kDa的蛋白，结构分析它含有依赖RNA的RNA聚合酶(RNA dependent RNA polymerase, RdRp)特征性的GDD(Glycine-Aspartate-Aspartate)结构域和其它保守的区域。