. Author manuscript; available in PMC: 2010 May 20.

Published in final edited form as: Nature. 2009 Jun 18;459(7249):931–939. doi: 10.1038/nature08157

Table 2.

Determinants of viral pathogenicity

Protein	Position	Pathogenicity		Swine-origin H1N1 viruses	Function	Ref.
Protein	Position	Low	High	Swine-origin H1N1 viruses	Function	Ref.
PB2	627	Glu	Lys	Glu	Replicative ability in some mammals including humans	46,47
PB2	701	Asp	Asn	Asp	Nuclear import kinetics affecting replicative ability in mice	53,55
PB1-F2	66	Asn	Ser	Truncated (11 a.a.)	Induction of apoptosis	74
HA		Single basic a.a.	Multiple basic a.a.	Single basic a.a.	HA cleavage	45
NS1	92	Asp	Glu	Asp	Unknown (Interferon response?)	65
NS1	C-term.	RSEV, deletion	ESEV	11 C-term. a.a. truncated	Unknown	69,70

a.a.: amino acid(s)