... Tamura D, Sakai-Tagawa Y, Noda T et al.: In vitro and in vivo characterization of new swine-origin H1N1 influenza viruses. Nature 2009, 460:1021–1025. 3. Kashiwagi T, Hara K, Nakazono Y, Hamada ... endonuclease activity, cap binding, and virion RNA promoter binding. J Virol 2006, 80:7789–7798. 18. Obayashi E, Yoshida H, Kawai F, Shibayama N, Kawaguchi A, Nagata K, Tame JR, Park SY: The ... and involves in promoter and cap binding [20,21]. PB1 contains active sites for nucleotide elongation [22,23] and binding to promoters of vRNA and cRNA [22,24,25]. PB2 involves in cap-snatching...