Figure 3.
Model showing non-templated functions of the 5’CL and 3’ NTR-poly(A) tail during initiation of negative-strand synthesis. The model shows the circular RNP complex used to initiate negative-strand synthesis. The long-range interaction between the 5’CL-RNP complex and the 3’ NTR-poly(A) RNP complex results in the formation of a 5’-3’ circular complex. This circular complex is thought to facilitate the initiation of negative-strand synthesis by using VPgpUpU as a primer on the 3’ poly(A) tail. This results in the synthesis of negative-strand RNA containing a 5’ terminal poly(U) sequence.