Table 6. Molecular analysis of A/TJ/1606/18 compared to other viruses.

Gene product	Function	Amino acid substitution	Virusa
			TJ	FJ	HN	HB	JS	GD	CA
HA	Altered receptor specificity	E190D	D	D	D	D	D	V	D
		D225E	E	E	E	E	E	E	D
NA	Antiviral resistance (oseltamivir)	H275Y	H	H	H	H	H	H	H
		N295S	N	N	N	N	N	N	N
PB2	Enhanced polymerase activity	L89V	V	V	V	V	V	V	V
	Virus replication in mammals	Q591R	R	Q	R	Q	Q	R	R
		E627K	E	E	E	E	E	E	E
		D701N	D	D	D	N	N	D	D
PB1	Between species transmission	X99H	H	H	H	H	H	H	H
		I368V	I	I	I	I	I	I	I
PA	Increased polymerase activity in mice	L336M	M	M	M	L	L	L	M
	Species-associated signature positions	K356R	R	R	R	K	K	K	R
		S409N	N	N	N	N	N	N	N
M1	Increased virulence in mice	T215A	A	A	A	A	A	A	A
M2	Antiviral resistance (amantadine)	S31N	N	N	N	N	N	N	N
NS1	Increased virulence in mice	P42S	S	S	S	S	S	S	S
NP	Mammalian-adaptive and increased virulence in mice	Q357K	K	K	K	Q	Q	K	K

^aTJ, A/Tianjin-baodi/1606/2018(H1N1);FJ, A/Fujian-cangshan/SWL624/2016(H1N1); HN, A/Hunan/42443/2015(H1N1);HB, A/Hebei-yunhua/SWL1250/2012(H1N1);JS, A/Jiangsu/1/2011(H1N1); GD, A/swine/Guangdong/1/2010(H1N1);CA, A/California/07/2009(H1N1)pdm09. For each virus, amino acid positions carrying the substitution are highlighted.