Table 1.

Molecular markers associated with receptor-binding properties of NA.

	Mutant	Subtypes	Function	Host	Refs
2SBS	N367S	H2N2/N2	A single reversion to the avian-virus-like sequence (N367S) restores Hemadsorption	Human	[49]
	N400S W403R	H2N2/N2	Affect the hemadsorption activity	Human	[49]
	T401A	H7N9/N9	Substrate binding via this site enhances NA catalytic activity	Human	[46]
	S366N	H1N1/N1	Increase viral NA enzyme activity	Human	[52]
	S366D
	K432E		α-2,6 SA, Enhance NA catalytic activity for a human virus	Human	[27]
	N369H TN368/369DS K432E	H5N1/N1 H1N1/N1	Affect the cleavage of fetuin-linked glycans	Avian Human	[43]
	S372N	H1N1/N1	S372N has the major effect on the 6′SLN-LC-2SBS binding	Human	[40]
	S430G	H5N1/N1	α-2,6 SA, NA S430G mutation plays a role in the affinity to human-type receptors	Human	[68]
NA	D151G	H3N2/N2	α-2,6 SA, Receptor binding properties	MDCK cell passage/ Human	[3,60,61]
	T148I			Human	[5,61]
	E119V			Human	[5]
	H150R	H3N2/N2	α-2,6 SA, NA-mediated agglutination of turkey RBCs	Human	[58,61]
	G147R	H3N2/N2	Receptor binding properties	Avian Human	[50,51]
		H1N1/N1
		H5N1/N1