Figure 3.

Viral interactions with Xrn1. (a) During infection with Tomato bushy stunt virus, Xrn1 can prevent the accumulation of viral RNA and of viral RNA intermediates that serve as substrates for recombination. (b) Some viruses prevent Xrn1 degradation of their uncapped genomic RNAs (gRNA) by having highly structured sequences in the 5^′ UTR, as in the case of 20S narnavirus, or by recruiting protein complexes to this region, as in the case of Picornaviruses. (c) Flaviviral RNAs contain Xrn1 blocking sequences in their 3^′ UTR. Xrn1‐mediated degradation of the RNAs up to the blocking sequence results in the generation of a functional subgenomic RNA, sfRNA.