Table 3.

Amino acid substitutions in H7N9 virus from the family clusters.

Gene	Amino acid position	H7N9 viral strains
		A/Anhui/1/2013	A/Fujian/10/2015	A/Fujian/16/2015	A/Fujian/18/2015	A/Fujian/22/2015
PB2	106	T	A	A	—	—
	191	K	E	E	E	E
	199	A	—	—	S	S
	340	R	K	K	—	—
	453	P	—	—	H	H
	508	R	—	—	K	K
	534	S	—	—	F	—
	559	N	T	T	T	T
	588	A	V	V	—	—
	627	K	—	—	E	—
	701	D	—	—	N	N
	707	A	S	S	—	—
	711	N	—	—	S	S
PB1	209	K	N	N	—	—
	213	N	T	T	—	—
	398	D	N	N	—	—
PA	100	A	—	—	V	V
	262	R	—	—	K	K
	272	N	—	—	D	D
	343	A	—	—	S	S
	394	N	—	—	D	D
	419	D	—	—	G	G
	561	M	—	—	I	—
HA	46	N	—	—	S	S
	109	S	N	N	—	—
	134	A	V	V	—	—
	177	L	I	I	I	I
	225	G	—	—	D	—
	299	S	—	—	R	R
	387	E	A	A	A	A
	490	S	R	R	R	R
	497	M	—	—	I	I
NP	237	A	—	—	—	T
NA	16	I	T	T	T	T
	46	H	R	R	—	—
	114	V	—	—	I	I
	212	V	—	—	—	A
	245	S	P	P	P	P
	251	D	—	—	E	E
	308	V	—	—	I	I
	325	N	S	S	S	S
	405	G	V	—	—	—
M2	24	E	D	D	D	D
	27	V	—	—	I	I
NS1	206	S	—	—	C	C

Note. The HA gene was under the H3 numbering system and the NA gene under the N2 numbering system. Other internal genes were numbered from the start codon (M).