Table 3.

Mutations determinants in polymerase genes that correlated to the replication, spread or pathogenicity of H9N2 viruses.

Protein	Amino acid position	Egyptian H9N2 under study	Avian preference	Mammalian preference	Reference
PB2	44	A	A	S	[44]
	64	M	M	T	[44]
	81	T	T	M	[47]
	199	A	A	S	[44]
	271	T	T	A	[44]
	256	D	D	G	[48]
	318	R(4), K(4)	K	R	[48]
	333	T	T	I	[40]
	355	M(6), I(2)	K	Q	[44]
	475	L	L	M	[40]
	482	K	K	R	[40]
	504	V	I	V	[45]
	588	A	A	I	[44]
	613	V	V	T	[40]
	627	V	E	K	[40]
	647	I	I	I	[40]
	661	A(7), T(1)	A	T	[40]
	674	A	A/S	T	[44]
	701	D	D	N	[40]
	702	K	K	R	[65]
	714	S(2),G(6)	S	R	[44]
PB1	13	P	L	P	[44]
	327	R	R	K	[48]
	336	V	V	I	[48]
	375	N	N	S	[44]
	538	D	D	G	[44]
	578	K	K	Q	[44]
	678	S	S	N	[44]
PB1-F2	68	T	T	I	[48]
	73	K	K	R	[48]
	76	V	V	A	[48]
	79	R	R	Q	[48]
	82	S	L	S	[48]
	87	E	E	G	[48]
PA	28	P	P	L	[48]
	55	D	D	N	[48]
	57	R(6),K(2)	R	Q	[48]
	65	S	S	L/Y	[44]
	100	V	V	A	[44]
	133	E	E	G	[44]
	225	S(7),G(1)	S	C	[48]
	241	C	C	Y	[48]
	268	L	L	I	[48]
	312	K	K	R	[48]
	356	K	K	R	[48]
	382	E	E	D	[48]
	400	S	Q/T/S	L	[48]
	404	A	A	S	[48]
	409	S(7),N(1)	S	N	[48]
	552	T	T	S	[44]
	556	Q	Q	R	[44]
	615	K	K	N	[44]