Table 1. Amino acid differences in the RBS of Aichi68 H3 an Anh13 H7 HAs.

The key amino acids in the 130-, 140-, 150-, 220-loop and 190-helix that bind to the base and extension region of the glycan receptors in Aichi68 and Anh13 are shown. The 150 loop has amino acids (positions 153 and 155) that are involved in contacts with the sialic acid in the base region and those that are involved in binding to extension region. See also Figure S3.

				Base (Neu5Acα2->3/6Galβ1-)														Extension (-4GlcNAcβ1-3Galβ1-4-)
HA	130-loop				140-loop	220-loop							150-loop		150-loop					190-Helix
	131	133	136	138	145	219	221	222	225	226	227	228	153	155	156	157	158	159	160	186	187	188	189	190	192	193	194	196
Aichi68	T	N	S	A	S	S	P	W	G	L	S	S	W	T	K	S	G	S	T	S	T	N	Q	E	T	S	L	V
Anh13	R	N	T	A	S	A	P	Q	G	L	S	G	W	L	S	N	T	D	N	V	S	T	A	E	T	K	L	G