Fig. 1

Predicted secondary structures of NS gene segment RNA regions 82–148 and 497–564 without and with mutations (a) 82–148 original sequence of A/Brevig Mission/1/1918 (H1N1) (hairpin), (b) 82–148 mutated sequence featuring G123A and A132G substitutions, (c)497–564 original sequence of A/Vietnam/1194/2004 (H5N1) (hairpin), (d) 497–564 mutated sequence featuring G511A, G512A and C537G substitutions