Initiation of cRNA Synthesis

Viral vRNA, complexed with NP protein, is bound by the trimeric viral polymerase complex in a stable secondary structure-dependent manner, referred to as a panhandle, fork or cork-screw (Fodor, 1994; Brownlee, 2002; Park, 2003; Crow, 2004). This RNA structure is made of both the 5’ and 3' ends of the vRNA. The polymerase is thought to first bind the 5' end of the vRNA and then the 3' end. Synthesis of cRNA initiates without a host cell methylated RNA cap as a primer (Beaton, 1986; Galarza, 1996; Deng, 2006; Engehardt, 2006).

病毒RNA（vRNA）与NP蛋白复合体在一种稳定的二级结构中结合，该结构被称为泛柄、叉形或螺旋状（Fodor, 1994；Brownlee, 2002；Park, 2003；Crow, 2004）。此RNA结构由vRNA的5'和3'端构成。聚合酶据信首先与vRNA的5'端结合，随后为3'端。cRNA的合成无需以宿主细胞甲基化RNA帽为引物启动（Beaton, 1986；Galarza, 1996；Deng, 2006；Engehardt, 2006）。